Category Archives: Atrial Fibrillation

Apple Heart Study: Despite The Ballyhoo, No Benefits Demonstrated, Harms Not Measured

The results of the Apple Heart Study, were presented this morning at the American College of Cardiology Scientific Sessions amid intense media scrutiny. The AHS is a “prospective, single arm pragmatic study” which had the primary objective of measuring the proportion of participants with an irregular pulse detected by the Apple Watch who turn out to have atrial fibrillation on subsequent ambulatory ECG patch monitoring.

 

I and over 400,000 other Apple Watch owners participated in the AH study by downloading the Apple Heart Study app and self-verifying our eligibility. 

My assessment is that we have learned little to nothing from the AHS that we didn’t already know. I’m also concerned that many patients suffered anxiety or unnecessary testing after being referred to urgent care centers, emergency departments, cardiologists or primary care providers and the results of these inappropriate referrals may never be determined.

Here is the study in a nutshell:

  1. Participants enrolled by submitting  information using the iPhone Heart Study app and none of their isubmitted nformation was verified.
  2. An irregular pulse notification was issued to 0.5% of participants who were then  contacted and asked to participate in a Telehealth visit with a doctor (who we will call Dr. Appleseed)
  3. Only 945 of the 2161 who received a pulse notification participated in the first study visit.
  4. Interestingly, Dr. Appleseed was empowered to send participants to the ER if they had symptoms (chest pain, shortness of breath, fainting/losing consciousness) It is not clear how many were sent to the ER and what their outcomes were but this flow diagram shows that 20 were excluded from further testing due to “emergent symptoms.”

  5. Another 174 participants were excluded after finding out at the first visit that they had a history of afib or aflutter and 90 due to current anticoagulant use (both of these factors were exclusion criteria which gives us an idea of how accurate the information was at the time of participant entry.)
  6. After all these exclusions only 658 ECG monitor patches were shipped to the participants of which only 450 were returned and analyzed.
  7. This means of the original 2161 participants who were notified of pulse irregularity, the study only reports data on 450 or 21%. Such a low rate of participation makes any conclusions from the study suspect.
  8. Of the 450 ECG patches analyzed only 34% were classified as having afib. Only 25% of this afib lasted longer than 24 hours.
  9. After the patch data was analyzed, patients had a second Telehealth visit with Dr. Appleseed who reviewed the findings with the patient. Per the initial published description of the methods of the AHS (see here) Dr. Appleseed  would tell the participant to head to the ER if certain abnormalities were found on the ECG.

Per the study description (apple heart study), Dr. Appleseed recommended a visit to the PCP for “AF or any other arrhythmia” detected by the patch:”

“If AF or any other arrhythmias have been detected in reviewing the ambulatory ECG monitor data, or if there are other non-urgent symptom identified by the study physician during the video visit that may need further clinical evaluation, the Study Telehealth Provider directs the participant to his or her primary health care provider”

At this point it seems likely that a lot of participants were instructed to go see their PCPs. Because as someone who looks at a lot of 2 week ambulatory ECG recordings I know that is the rare recording that does not show “other arrhythmias.”

Even more distressing is the call that participants would have received based on “the initial technical read:” I’m presuming this “technical read” was by a technician and not by a cardiologist. In my experience, many initial reads from long term monitors are inaccurate.

“If the initial technical read identifies abnormalities that require urgent attention (ventricular tachycardia or ventricular fibrillation, high-degree heart block, long pauses, or sustained and very rapid ventricular rates), then the participant is contacted immediately and directed to local emergency care or advised how to seek local emergency care.”

I wonder how many  ERs had AHS participants show up saying they had been told they had a life-threatening arrhythmia? How much down stream testing with possible invasive, life-threatening procedures such as cardiac catheterization were performed in response to these notifications?

Overall, these findings add nothing to previous studies using wearable PPG technology and they certainly don’t leave me with any confidence that the  Apple Watch is accurately automatically detecting atrial fibrillation.

Was more harm than good done by the Apple Heart Study?

We will never know. The strength of this study, the large number of easily recruited participants is also its Achilles heel. We don’t know that any information about the participants is correct and we don’t have any validated follow up of the outcomes. In particular, I’m concerned that we don’t know what happened to all of these individuals who were sent to various health care providers thinking there might be something seriously wrong. 

Perhaps Apple and Stanford need to review the first dictum of medicine: Primum Non Nocere, First Do No Harm.

Tachogramophobically Yours,

-ACP

Apple Watch Fails To Notify Patient Of 3 Hour Episode Of Rapid Atrial Fibrillation

Apple claims that its Apple Watch can detect atrial fibrillation (AF) and appropriately notify the wearer when it suspects AF.

This claim comes with many caveats on their website:

Apparently it needs to record 5 instances of irregular heart beat characteristic of atrial fibrillation over at least 65 minutes before making the notification.

This feature utilizes the watch’s optical heart sensors, is available  in Apple Watch Series 1 or later and has nothing to do with the Apple Watch 4 ECG recording capability which I described in detail in my prior post.

Failure To Detect AF

A patient of mine with known persistent AF informed me yesterday that she had gone into AF and remained in it for nearly 3 hours with heart rates over 100 beats per minute and had received no notification. She confirmed the atrial fibrillation with both AW4 recordings and AliveCor Kardia recordings while she was in it.

The watch faithfully recorded sustained heart rates up to 140 BPM but never alerted her of this even though the rate was consistently over her high heart rate trigger of 100 BPM.

The patient had set up the watch appropriately to receive notifications of an irregular rhythm.

Reviewing her tracings from both the AW4 and the Kardia this was easily diagnosed AF with a rapid ventricular response.

What does Apple tell us about the accuracy of the Apple Watch AF notification algorithm? All we know is the unpublished , non peer-reviewed data they themselves collected and presented to the FDA.

From this link on their website Apple says:

In a study of 226 participants aged 22 years or older who had received an AFib notification while wearing Apple Watch and subsequently wore an electrocardiogram (ECG) patch for approximately 1 week, 41.6% (94/226) had AFib detected by ECG patch. During concurrent wear of Apple Watch and an ECG patch, 57/226 participants received an AFib notification. Of those, 78.9% (45/57) showed concordant AFib on the ECG patch and 98.2 % (56/57) showed AFib and other clinically relevant arrhythmias. These results demonstrate that, while in the majority of cases the notification will accurately represent the presence of AFib, in some instances, a notification may indicate the presence of an arrhythmia other than AFib. No serious device adverse effects were observed

This tells us that about 80% of notifications are likely to be Afib whereas 20% will not be Afib. It is unclear what the “other clinically relevant arrhythmias”  might be. If I had to guess I would suspect PVCS or PACS which are usually benign.

If 20% of the estimated 10 million Apple Watch wearers are getting false positive notifications of afib that means 2 million calls to doctor or visits to ERs that are not justified.  This could be a huge waste of resources.

Thus the specificity of the AF notification is 80%. The other important parameter is the sensivitiy. Of the cases of AF that last >65 minutes how many are detected by the app?

Apple doesn’t seem to have any data on that but this obvious case of rapid AF lasting for 3 hours does not give me much confidence in their AF detection algorithms.

They do have a lot of CYA statements indicating you should not rely on this for detection of AF:

It is not intended to provide a notification on every episode of irregular rhythm suggestive of AFib and the absence of a notification is not intended to indicate no disease process is present; rather the feature is intended to opportunistically surface a notification of possible AFib when sufficient data are available for analysis. These data are only captured when the user is still. Along with the user’s risk factors, the feature can be used to supplement the decision for AFib screening. The feature is not intended to replace traditional methods of diagnosis or treatment.

My patient took her iPhone and Apple Watch into her local Apple store to find out why her AF was not detected. She was told by an Apple employee that the Watch does not detect AF but will only notify her if her heart rate is extremely low or high. I had asked her to record what they told her about the problem.

As I’ve written previously (see here) the Apple Watch comes with excessive hype and minimal proof of its accuracy. I’m sure we are going to hear lots of stories about AF being detected by the Watch but we need some published, peer-reviewed data and we need to be very circumspect before embracing it as a reliable AF monitor.

Skeptically Yours,

-ACP

Putting The Apple Watch 4 ECG To The Test In Atrial Fibrillation: An Informal Comparison To Kardia

My first patient this morning, a delightful tech-savvy septagenarian with persistent atrial fibrillation told me she had been monitoring her rhythm for the last few days using her Apple Watch 4’s built in ECG device.

Previously she had been using what I consider the Gold Standard for personal ECG monitoring- AliveCor’s Kardia Mobile ECG   and I monitored her recordings through our Kardia Pro connection.

I had been eagerly awaiting Apple’s roll out since I purchased the AW4 in September (see here) and between patients this morning I down-loaded and installed the required iPhone and Watch upgrades and began making AW4 recordings.

Through the day I tried the AW4 and the Kardia on patients in my office.

Apple Watch 4 ECG Is Easy and Straightforward

The AW4 ECG recording process is very easy and straightforward. Upon opening the watch app you are prompted to open the health app on your iPhone to allow connection to the Watch ECG information. After this, to initiate a recording simply open the Watch ECG app and hold your finger on the crown.

Immediately a red ECG tracing begins along with a 30 second countdown.

Helpful advice to pass the time appears below the timer:

“Try Not to move your arms.”

and

“Apple Watch never checks for heart attacks.”

When finished you will see what I and my patient (who mostly stays in sinus rhythm with the aid of flecainide) saw-a declaration of normality:

Later in the day I had a few patients with permanent  atrial fibrillation put on my watch.

This seventy-something farmer from Bowling Green, Missouri was easily able to make a very good ECG recording with minimal instruction

 

 

 

 

The AW4 nailed the diagnosis as atrial fibrillation.

We also recorded a Kardia device ECG on him and with a little more instruction the device also diagnosed atrial fibrillation

 

 

After you’ve made an AW4 recording you can view the PDF of the ECG in the Health app on your iPhone where all of your ECGs are stored. The PDF can be exported to email (to your doctor) or other apps.

ECG of the Bowling Green farmer. I am not in afib.

 

Apple Watch Often “Inconclusive”

The AW4 could not diagnose another patient with permanent atrial fibrillation and judged the recording “inconclusive”

The Kardia device and algorithm despite a fairly noisy tracing was able to correctly diagnose atrial fibrillation in this same patient.

 

 

I put the AW4 on Sandy, our outstanding echo tech at Winghaven who is known to have a left bundle branch block but remains in normal rhythm and obtained this inconclusive report .

 

 

 

 

Kardia, on the other hand got the diagnosis correctly:

 

 

 

 

One Bizarre Tracing by the AW4

In another patient , an 87 year old lady with a totally normal recording by the Kardia device, the AW4 yielded a bizarre tracing which resembled ventricular tachycardia:

Despite adjustments to her finger position and watch position, I could not obtain a reasonble tracing with the AW4.

The Kardia tracing is fine, no artifact whatsoever.

 

 

 

 

 

 

 

 

 

What can we conclude after today’s adventures with the Apple Watch ECG?

This is an amazingly easy, convenient and straightforward method for recording a single channel ECG.

I love the idea that I can record an ECG whereverI am with minimal fuss. Since I wear my AW4 almost all the time I don’t have to think about bringing a device with me (although for a while I had the Kardia attached to iPhone case that ultimately became cumbersome.)

Based on my limited sample size today, however, the AW4 has a high rate of being uncertain about diagnoses. Only 2/3 cases of permanent atrial fibrillation were identified (compared to 3/3 for the Kardia) and only 4/6 cases of sinus rhythm were identified.

If those numbers hold up with larger numbers, the AW4 is inferior to the Kardia ECG device.

I’d rather see the AW4 declare inconclusive than to declare atrial fibrillation when it’s not present but this lack of certainty detracts from its value.

What caused the bizarre artifact and inconclusive AW4 tracing in my patient is unclear. If anybody has an answer, let me know.

We definitely need more data and more studies on the overall sensitivity and specificity of the AW4 and hopefully these will be rapidly forthcoming.

For most of my patients the advantages of the AW4 (assuming they don’t already have one) will be outweighed by its much greater cost and we will continue to primarily utilize the Kardia device which will also allow me to view all of their recordings instantaneously in the cloud.

Conclusively Yours,

-ACP

Has REDUCE-IT Resurrected Fish OIl Supplements (And Saved Amarin)?

The answers are no and yes.

There is still no reason to take over the counter fish oil supplements.

In fact, a study published Saturday found that fish oil supplementation (1 g per day as a fish-oil capsule containing 840 mg of n−3 fatty acids, including 460 mg of eicosapentaenoic acid [EPA] and 380 mg of docosahexaenoic acid [DHA]

did not result in a lower incidence than placebo of the primary end points of major cardiovascular events (a composite of myocardial infarction, stroke, or death from cardiovascular causes) and invasive cancer of any type.

However, another study  published Saturday (REDUCE-IT) and presented at the annual American Heart Association Scientific Sessions to great fanfare found that an ethyl-ester formulation (icosapent ethyl) of eicosapentanoic acid (EPA, one of the two main marine n-3 fish oils)  reduced major cardiovascular events by 25% in comparison to placebo.

When I wrote about Icosapent ethyl (brand name Vascepa) in a previous blog post in 2015 there was no data supporting its use:

A fish oil preparation, VASCEPA,  available only by prescription, was approved by the FDA in 2012.

Like the first prescription fish oil available in the US, Lovaza, VASCEPA is only approved by the FDA for treatment of very high triglycerides(>500 mg/dl).

This is a very small market compared to the millions of individuals taking fish oil thinking that  it is preventing heart disease.

The company that makes Vascepa (Amrin;$AMRN)would also like to have physicians prescribe it to their patients who have mildly or moderatelyelevated triglycerides between 200 and 500 which some estimate as up to 1/3 of the population.

The company has a study that shows that Vascepa lowers triglycerides in patients with such mildly to moderately elevated triglycerides but the FDA did not approve it for that indication.

Given the huge numbers of patients with trigs slightly above normal, before approving an expensive new drug, the FDA thought, it would be nice to know that the drug is actually helping prevent heart attacks and strokes or prolonging life.

After all, we don’t really care about high triglycerides unless they are causing problems and we don’t care about lowering them unless we can show we are reducing the frequency of those problems.

Data do not exist to say that lowering triglycerides in the mild to moderate range  by any drug lowers heart attack risk.

In the past if a company promoted their drug for off-label usage they could be fined by the FDA but Amarin went to court and obtained the right to promote Vascepa to physicians for triglycerides between 200 and 500.

Consequently, you may find your doctor prescribing this drug to you. If you do, I suggest you ask him if he recently had a free lunch or dinner provided by Amarin, has stock in the company (Vascepa is the sole drug made by Amarin and its stock price fluctuates wildly depending on sales and news about Vascepa) or gives talks for Amarin.

If he answers no to all of the above then, hopefully, your triglycerides are over 500.

And although elevated triglycerides confer an elevated CV risk nearly all prior trials evaluating different kinds  of triglyceride-lowering therapies, including extended-release niacin, fibrates, cholesteryl ester transfer protein inhibitors, and omega-3 fatty acids have failed to show reductions in cardiovascular events

REDUCE-IT, Amarin trumpeted widely in September (before the actual data was published)  now provides impressive proof that it prevents cardiovascular disease. Has the skeptical cardiologist changed his mind about fish oil?

Vascepa Is Not Natural Fish Oil

Although Amarin’s marking material states “VASCEPA is obtained naturally from wild deep-water Pacific Ocean fish” the active ingredient is an ethyl ester form of eicosapentoic acid (EPA) which has been industrially processed and distilled and separated out from the other main omega-3 fatty acid in fish oil (DHA or docosohexanoieic acid).

Natural fish oil contains a balance of EPA and DHA combined with triacylglycerols (TAGS).

So even if the REDUCE-IT trial results can be believed they do not support the routine consumption of  over the counter fish oil supplements for prevention of cardiovascular disease.

Does REDUCE-IT  Prove The Benefit of Purified High Dose EPA?

REDUCE-IT was a large (8179 patients) randomized, double-blind placebo controlled trial

Eligible patients had a fasting triglyceride level of 150 to 499 mg per deciliter  and a low-density lipoprotein (LDL) cholesterol level of 41 to 100 mg per deciliter  and had been receiving a stable dose of a statin for at least 4 weeks. In 2013 the protocol was changed and required a triglyceride level>200 mg/dl.

Participants were randomized to icosapent ethyl (2 g twice daily with food [total daily dose, 4 g]) or a placebo that contained mineral oil to mimic the color and consistency of icosapent ethyl and were followed for a median of 4.9 years. A primary end-point event occurred in 17.2% of the patients in the icosapent ethyl group, as compared with 22.0% of the patients in the placebo group.

More importantly, the hard end-points of CV death, nonfatal stroke and heart attack were also significantly lower in the Vascepa arm compared to the “placebo” arm.

These results are almost unbelievably good and they are far better than one would have predicted given only a 17% reduction in triglycerides.

This makes me strongly consider prescribing Vascepa (something I heretofore have never done) to my higher risk patients with triglycerides over 200 after we’ve addressed lifestyle and dietary contributors.

Perhaps the high dose of EPA (4 grams versus the 1 gram utilized in most trials) is beneficial in stabilizing cell membranes, reducing inflammation and thrombotic events as experimental data has suggested.

Lingering Concerns About The Study

Despite these great results I have some concerns:

  1. The placebo contained mineral oil which may not have been neutral in its effects. In fact, the placebo arm had a significant rise in the LDL cholesterol.
  2. Enrolled patients were predominantly male and white. No benefit was seen in women.
  3. Higher rates of serious bleeding were noted in patients taking Vascepa
  4. Atrial fibrillation developed significantly more often in Vascepa patients (3.1%) versus the mineral oil patients (2.1%)

Finally, the trial was sponsored by Amarin Pharma. This is an aggressive company that I don’t trust.  The steering committee consisted of academic physicians (see the Supplementary Appendix), and representatives of the sponsor developed the protocol,  and were responsible for the conduct and oversight of the study, as well as the interpretation of the data. The sponsor was responsible for the collection and management of the data. All the data analyses were performed by the sponsor,

After i wrote my negative piece on Vascepa in 2015 a number of Amarin investors attacked me because Vascepa is the only product Amarin has and any news on the drug dramatically influences its stock price. Here is the price of Amarin stock in the last year.

The dramatic uptick in September corresponds to the company’s announcement of the topline results of REDUCE-IT. Since the actual results have been published and analyzed the stock has dropped 20%.

High Dose Purified and Esterified EPA-Yay or Nay?

I would love to see another trial of high dose EPA that wasn’t totally under the control of Amarin and such trials are in the pipeline.

Until then, I’ll consider prescribing Amarin’s pills to appropriate patients* who can afford it and who appear to have significant residual risk after statin therapy*.

But, I will continue to tell my patients to stop paying money for useless OTC fish oil supplements.

Megaskeptically Yours,-

ACP

N.B.* Appropriate patients will fit the entry criteria for REDUCE-IT described below.

Patients could be enrolled if they were 45 years of age or older and had established cardiovascular disease or were 50 years of age or older and had diabetes mellitus and at least one additional risk factor. Eligible patients had a fasting triglyceride level of 150 to 499 mg per deciliter (1.69 to 5.63 mmol per liter) and a low-density lipoprotein (LDL) cholesterol level of 41 to 100 mg per deciliter (1.06 to 2.59 mmol per liter) and had been receiving a stable dose of a statin for at least 4 weeks;

So either secondary prevention (prior heart attack or stroke) or primary prevention in patients with diabetes and another risk factor.

 

 

AliveCor’s Mobile ECG With Kardia Pro Is Eliminating Any Need For Short or Long Term Cadiac Monitors For Most of My Afib patients: A Tale of Four Cardioversions

I described in detail in March (see here) my early experience in utilizing AliveCor’s KardiaMobile ECG  device in conjunction with their Kardia Pro cloud service to monitor my patient’s with atrial fibrillation (afib). Since that post the majority of my new afib patients have acquired the Kardia device and use it regularly to help us monitor their afib.

This capability has revolutionized my management of atrial fibrillation. In those patients who choose to use AliveCor there is really no need for long-term monitors (Holter monitors, Zio patches, cardiac event monitors) and no need for patients to come to the office to get an ECG when they feel they have gone into afib.

When one of my Kardia Pro patients calls with symptoms or concern of afib, I quickly pull up their chart at Kardiapro.com and review their recordings to determine if they are in or out of rhythm. Most treatment decisions can then be handled over the phone without the need for ordering a monitor or an emergency room or office visit.

One 24 hour period will suffice to show how important KardiaPro is now to my management of my patients with afib

A Day In The Afib Life

Tuesdays I spend the day working in the heart station at my hospital. Typically, on these days I will supervise stress tests, read ECGs and echocardiograms, perform TEES and electrical cardioversions. On a recent Tuesday I had 3 patients scheduled for cardioversion of their atrial fibrillation.

The day before one of these patients called indicating that he suspected he had reverted back to normal rhythm (NSR) based on his Kardia readings. He had had a prior cardioversion after which we know (thanks to daily Kardia recordings) he reverted to afib in 5 days. Subsequently we had started him on flecainide, a drug for maintenance of NSR and scheduled him for the cardioversion.

Not uncommonly after starting flecainide patients will convert to NSR but if they don’t we  proceed to an electrical cardioversion.

I logged into KardiaPro and reviewed his dashboard and sure enough his last two ECGs showed sinus rhythm. I congratulated him on this and we canceled his cardioversion for the next day, saving the lab the time and expense of a cancellation the day of the procedure. The patient avoided much stress, time and inconvenience.

Screen Shot 2018-10-13 at 7.27.49 AM
ECG recordings showing the patient had transitioned from afib (bottom two panels) to NSR (top two panels) after starting flecainide.

It is important to note that in this patient there was no great jump in heart rate with afib compared to NSR. For many patients the rate is much higher with the development of afib and this is often detected by non ECG wearable monitors (like an Apple Watch.)  But for patients like this one, an ECG is the only way to know what the rhythm is.


A second patient with afib who had elected not to acquire an AliveCor ECG device showed up for his cardioversion on Tuesday and after evaluating his rhythm it was clear he had spontaneously reverted back to NSR.  Prior to my adoption of KardiaPro this was a common and scenario.


The third scheduled cardioversion of the day showed up in afib and we successfully cardioverted him back to NSR. I had not addressed utilizing AliveCor with him. Prior to the procedure he asked me about likely outcomes.

My standard response to this question is that we have a 99.9% success rate in converting patients back to NSR at the time of the cardioversion. However, I can’t predict how long you will stay in NSR after the cardioversion. NSR could last for 5 days or it could last for 5 years. Adding medications like flecainide or amiodarone can significantly reduce the risk of afib recurrence after cardioversion.

At this point he asked me “How do I know if I am in afib?” Whereas many afib patients immediately feel bad and are aware that they have gone out of rhythm, this man like many others was not aware.

Prior to AliveCor my answer would have been to check the pulse daily or look for evidence of high or irregular heart rates on BP monitors or fitness wearables. This scenario provided a wonderful opportunity to test the AliveCor’s accuracy at detecting AF in him. I pulled out my trusty AliveCor mobile ECG and prior to the cardioversion we made the recording below

img_0702.jpg

After the cardioversion we repeated the Alivecor recording and the rhythm (AliveCor’s interpretation) had changed from afib  to NSR.

Needless to say, this patient purchased a Kardia device the next day and since the cardioversion he’s made a daily recording which has confirmed NSR. I just logged into Kardia Pro and sure enough he made a recording last night and it showed NSR.


Later in the week I received a call from a patient I had electrically cardioverted a few days earlier. His Kardia device had detected that he had gone back into afib.

I logged into my Mac and saw his KardiaPro chart below.

Kardia Pro displays green dots corresponding to NSR and orange triangles corresponding to afib with 100% accuracy in this patient.

 

 

With perfect precision KardiaPro had verified NSR after the cardioversion lasting for 36 hours. For some reason after dinner the day after the cardioversion, the patient had  reverted back to afib. This knowledge greatly facilitates subsequent treatment and eliminates the need for in office ECGs and long term monitors.


Utilization of the Kardia device with the Kardia Pro monitoring service has proved for me to b a remarkable improvement in the management of patients with afib. Managing non Kardia afib patients feels like navigating a forest with a blindfold.

The improvement is so impressive that I find myself exclaiming to my assistant, Jenny, several times a week “How do other cardiologists intelligently care for afibbers without AliveCor?”

I have a few patients who balk at the 15$ per month charge for Kardia Pro and ask why the device and this monthly charge aren’t covered by insurance or Medicare. Given the dramatic reduction that I have noticed in my use of long-term monitors  as well as  office and ER visits in this population, CMS and third-party insurers would be wise to explore Kardia monitoring as a more cost-effective way of monitoring afib patients.

antifibrillatorily Yours

-ACP

N.B. I realize this post appears to be an unmitigated enthusiastic endorsement of a commercial product which is quite uncharacteristic for the skeptical cardiologist.

One might wonder if the skepcard is somehow biased or compensated for his endorsement of Kardia.

In all honesty, this sprung from my love of the device’s improvement in my afib management and I have received no payment, monetary or otherwise from AliveCor and I own none of their stock (and I’m not even sure if it is on the stock market.)

A Review Of The QardioCore ECG Strap From A Patient’s Perspective

One of my patients has been on the cutting edge of personal cardiac monitoring devices and I asked him to share his recent experience with the QardioCore ECG strap. What he sent me is a fascinating description of how the device works (which is unique in this area) along with how it was crucial in diagnosing the cause of his recent symptoms. I’m sharing it below.


I’m a current patient of the Skeptical Cardiologist and have experienced recovery from 14 months of Atrial Fibrillation with Rapid Ventricular Response, and subsequent heart failure.   While I haven’t had symptoms of heart failure or Atrial Fibrillation in over 6 months, as a former long-distance cyclist, I had been following the progress for the FDA approval of the QardioCore device since it was announced over a year ago.   You can learn more about their device at https://www.getqardio.com/qardiocore-wearable-ecg-ekg-monitor-iphone/, but I’ve pasted text from their website here: (https://support.getqardio.com/hc/en-us/articles/115000257105-Electrocardiogram-ECG-EKG- )

“QardioCore is a clinical-quality wearable electrocardiogram recorder. An electrocardiogram – often abbreviated as ECG or EKG – is a test that measures the electrical activity of the heart. With each heart beat, an electrical impulse (or “wave”) travels through the heart. This wave causes the muscle to squeeze and pump blood from the heart.

 

An ECG gives two major kinds of information. First, by measuring time intervals on the ECG, a doctor can determine how long the electrical wave takes to pass through the heart. Finding out how long the wave takes to travel from one part of the heart to the next shows if the electrical activity is normal or slow, fast or irregular. Second, by measuring the amount of electrical activity passing through the heart muscle, a cardiologist may be able to find out if parts of the heart are too large or are overworked. During an ECG, several sensors, called electrodes, capture the electrical activity of the heart.

QardioCore is ideal for health conscious individuals or those with known or suspected heart conditions to record their everyday ECGs, physical activity, sport performance and medical symptoms and share their data with their doctors. Medical professionals can use QardioCore to quickly assess heart rate and rhythm, screen for arrhythmias, and remotely monitor and manage patients who use QardioCore.

 

QardioCore should be only used in conjunction with professional medical advice, diagnosis, or treatment, and not as a substitute, or a replacement for it. Qardio creates products and services that conform to US quality, safety and security requirements for medical products, while delivering a modern user experience. QardioCore will begin selling in the US after receiving US Food and Drug Administration clearance.”

Unfortunately, the US FDA tends to move slowly, and we can only speculate as too why, but the device is not available for purchase here.   However, I found a friend in France who purchased one for me and shipped me the device.   It is not illegal for me to use the device here, but it is not allowed to be sold here in the US.

I use an Apple I-Phone 8Plus and have used both the AliveCor KardiaBand and the KardiaMobile found here (https://store.alivecor.com), and reviewed by the esteemed Skeptical Cardiologist in other posts as well.   While I find it as a useful tool, my only dissatisfaction is that I want to passively monitor my heart during sporting activities and look for rhythm disturbances.   While I’m no expert in either sporting activities or rhythm disturbances, I’ve completed some healthy reading and living on both subjects and have a general awareness of the topic.

The QardioCore device is simple to wear, comes with three belts that can be used and cleaned, and comes with a charging cable.   Everything that the app, and the product does, seems to be accurately described on their web site, so I won’t cover off on details here.   You can read more about it at this link:   https://www.getqardio.com/qardioapp/   My only dissatisfaction with this device, and other blue tooth devices, has nothing to do with the device itself.   Apple seems to randomly disconnect from Bluetooth devices with their phones.   I don’t pretend to know the specific mechanisms for the problem, but my blue tooth devices for bicycling, music headsets, and heart monitoring have all been plagued with intermittent blue tooth connection problems.   So, at times, I find myself having to restart their app to keep the device connected, which is a minor annoyance.   

I also use the QardioArm product to measure and monitor my blood pressure and am satisfied with it as well.

What follows is my anecdotal experiences of September 26, 2018 through the present day and I agreed to write about them here, in case it provides useful insight to others in some way.

As a person with a short-term history of heart problems, I tend to capture a lot of data with my devices.   I monitor things like heart rate variability, blood pressure, Alivecor Kardia readings, sleep history, etc.   I make an active attempt to monitor my levels of stress, but I know for certain that I lead a stressful life.  I work longer hours than I should, probably sleep less than I should, exercise less than I like and should, and medicate and pray far less than I should.  So, I don’t want to imply that anything that happened is the fault of the medical system, bad blue tooth connections, bad medical care, or bad advice from the Skeptical Cardiologist or any other medical professional.   I tend to listen well, learn well, but I don’t always act as I should.  But, I’m responsible for my choices, my decisions, and I live with the results of my actions.

With that said, I was sitting at the office on Wednesday September 26th, 2018 and was working away without a care in the world.   As a computer programmer, I’m very sedentary and enjoy my work.   I was wearing my QardioCore ECG strap at the time because I’m a big believer in capturing baseline data for my general living and lifestyle.   I believe this data was invaluable in my first episode of heart problems, but have no supporting evidence to support my claim.   At around 8:58:42 AM, I felt somewhat bad, and felt my heart racing.   I glanced over at my phone which was showing the ECG trace at the time and noticed what I believed was Atrial Flutter at the time.   But, after about 20 seconds, the ECG trace returned to normal, and I felt fine again.   I made a quick note of the time, because I was busy, and continued working for the day.  The Quardio App provides no diagnostic information, so it doesn’t analyze and interpret ECG patterns like the Alivecor Kardia app does. When I arrived at home later that day, I went back to look at the ECG trace, as the Quardio App easily allows that through features of the App.   When I found the point in time of the ECG, I became concerned immediately because I believe that I was seeing a pattern that I recognized as Ventricular Tachycardia, a condition that comes in many forms, and has many causes, but can be fatal if not properly treated.   As my cortisol levels increased, I contacted Dr. Google and just quickly verified that I wasn’t completely nuts, although I acknowledge there may be some partial nuttiness there.   While going through this process, I experienced another 4 second episode which only increased my anxiety levels.   After contacting my wife and asking her to return home, and informing some family members, I felt it best that I should contact the Skeptical Cardiologist after hours for input on my problem.   I hate to bother the doctor, as he is a busy man, but contacted his after-hours number.  While the operator on the other end of the line wondered what kind of nut case I was, she kindly contacted the doctor who promptly called me on my cell phone.    I had informed the kind doctor that I had the device about three weeks prior, so he was already aware that I had the QardioCore.   I quickly informed the doctor that I believed I had experienced at least one but possibly two cardiac events.   After briefly talking, I hung up the phone and texted him photos of the screens from the Quardio App, so he could see the ECG tracings.   Here are the photos that I sent to the Skeptical Cardiologist via text:

 

 

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I believe this tool is valuable in many ways, but I believe that it was helpful for the Skeptical Cardiologist, as it helped narrow our focus of blood tests, scans, and potential procedures to run in a faster than normal basis.   Normally, if I had not had evidence (accurate or not), I would have had to schedule an appointment, or go to ER.   At that point, they would have either ordered an event monitor for me to wear while I was away from the hospital, or they would have had to admit me.   Since I had a past history of Atrial Fibrillation, which isn’t quite as serious, we would have been sent home with an event monitor and instructions to take it easy and continue to take meds.   We would have run more blood work, and more scans, but the point is that we would have been more broadly focused, as we would have had to generally guess as to the nature of the event and narrow it down.

I recognize that this is one of the controversies that is active in clinical cardiology, as I listen to podcasts by Dr. John Mandrola and others regarding the latest cardio devices, procedures and research.   I realize that many Cardiologists are not in favor of devices like these, because they lead to uninformed conclusions, which leads to unneeded stress on both patients and their stressed-out doctors and cardiologists.   I’ve listened to both sides of the argument, and I have my own opinions that I won’t express here.   I will just say that I believe that this device saved me time, possibly my life (as I don’t know what I don’t know, unless I know to look), and some time in hastening and narrowing my therapy choices.

I will say that my wife and I were extremely happy with the services provided by his staff, himself, his colleagues, and the hospital staff as well.   While I am confident I may be considered a difficult patient by some, or many, they were very thorough and kind in their treatment and explanation of my treatment options.

I hope that my experience adds helpful insight to the discussion.   I’m confident that the Skeptical Cardiologist will add to this post, with his views on the events I’ve discussed above.   And, I believe he appreciates having a Skeptical Patient every now and then as well.


As The Skeptical Patient wrote,  this device is not sold in the United States. Having seen it in action now, I’m eager to get my hands on one and evaluate it further. It could dramatically alter home arrhythmia monitoring. For this patient it was incredibly helpful.  If any of my European or Australian readers has experience with it please let me know.

Qardio makes a stylish, accurate and portable home BP monitor that I’ve written favorably about here.

Qardiodynamically Yours,

-ACP

N.B. Featured image of man running on beach with QardioCore is not of my patient.

Apple’s Alternative Facts And The Giant Watch Restaurant Next Door To AliveCor

As I pointed out Friday,  Apple’s claim that the ECG sensor on their new Apple Watch 4  (available “later this year”) is  “the First ECG product offered over the counter directly to consumers” is totally bogus.

AliveCor’s Kardia mobile ECG device was approved by the FDA  for over the counter direct to consumer sales on February 10, 2014. Apple had to have known this as they worked with AliveCor to bring the first Apple Watch based ECG device to FDA approval in 2017.

I tried but failed to get AliveCor founder Dr. David Albert’s thoughts on Apple’s disinformation but Yahoo finance was able to speak to Vic Gundotra, the CEO of AliveCor:

Over at the headquarters of AliveCor, a startup based in Google’s hometown of Mountain View, they, too, were surprised by the announcement, CEO Vic Gundotra said in a phone interview on Thursday. Gundotra is a former Googler, widely known as the executive behind the Google+ social network.

Specifically, Gundotra says that his company was confused by Apple’s claims that the Series 4 will be the first over-the-counter ECG testing device for consumers. AliveCor is a 49-employee startup that makes over-the-counter ECG testing devices and software, including an FDA-cleared band for the Apple Watch, called KardiaBand, and a version that attaches to a smartphone, called Kardia.

Gundotra was also surprised by Apple’s claims of ECG primacy

“We were watching [the announcement], and we were surprised,” Gundotra said. “It was amazing, it was like us being on stage, with the thing we’ve been doing for 7 years,” referring to AliveCor’s product for detecting atrial fibrillation  (AFib), a tough-to-spot heart disorder that manifests as an irregular, often quick heart rate that can cause poor circulation.

“Although when they said they were first to go over-the-counter, we were surprised,” he continued. “Apple doesn’t like to admit they copy anyone, even in the smallest things. Their own version of alternative facts.”

One man’s alternative fact is another (less polite) man’s lie.

Gundotra apparently views Apple’s entry as a good thing

“We love that Apple is validating AFib; just wait until you see what AliveCor is going to do next,” he said. “We were a great restaurant in a remote section of town, and someone just opened a giant restaurant right next to us, bringing a lot more attention.”

And as I pointed out previously, the AliveCor mobile ECG device (not the Kardia Band) is significantly cheaper than an Apple Watch and has multiple studies showing its accuracy. Interestingly, Gundotra indicates AliveCor sales has increased after the Apple announcement,.

“Ours is $99, theirs is $399, our sales popped yesterday, big time,”

Antialternafactively Yours,

-ACP

The New Apple Watch 4: Cardiac Accuracy Unknown, “Game-Changing” Benefits Overblown

On February 10, 2014 AliveCor, Inc. announced that its heavily validated personal  mobile ECG monitor had received FDA over-the counter clearance. Previously the device, which allows recording of a single-lead ECG and, in conjunction with a free smart-phone app, can diagnose atrial fibrillation was only available by prescription.

Since 2013, I have been successfully using this device with my patients who have atrial fibrillation (and writing about it extensively)

Apple COO Jeff Williams standing in front of (presumably) an ECG obtained by Apple Watch 4. It’s OK quality (but smallish p waves). Is that the best they could do? Notice that it is making a diagnosis of sinus rhythm. This PDF can be mailed “to your doctor.”

I was shocked, therefore, to hear the COO of Apple, Jeff Williams, announce that Apple will be offering in its new Apple Watch 4  “the first ECG product offered over the counter directly to consumers.”

This seemed blatantly inaccurate as AliveCor’s device clearly preceded by 4 years Apple’s claim.

Furthermore, AliveCor’s Kardia Band which converts any Apple Watch into a single-lead ECG  (which I’ve written about here and here) has been available and providing the Apple Watch-based ECGs since November 30, 2017.

AliveCor has an outstanding website which documents in detail all the research studies done on their products (there are dozens and dozens of linked papers) and all of their press releases dating back to 2012. It also explains in detail how the product works.

The title of their November 30, 2017 release was  FDA Clears First Medical Device Accessory for Apple Watch®

AliveCor shortly thereafter (December 12, 2017) announced Smart Rhythm , an Apple Watch app that monitors your rhythm and alerts you if it thinks you are in atrial fibrillation. I’ve discussed Smart Rhythm here.

Apple’s Watch will tell you that you are not in atrial fibrillation. Given that we don’t know how accurate it is, should that be reassuring?

The new Apple Watch’s rhythm monitoring app sounds a lot like Smart Rhythm but without any of the documentation AliveCor has provided.

So, within 10 months of Alivecor providing the world with the first ever wearable ECG (and proven its accuracy in afib) Apple seems to have come out with a remarkably similar product.

The major difference between Apple and AliveCor is the total lack of any reviewable data on the accuracy of the Apple device. Yes, that’s right Apple has provided no studies and no data and we have no idea how accurate its ECG device is (or its monitoring algorithm).

For all we know, it could diagnose sinus rhythm with frequent APCS or PVCs consistently as atrial fibrillation, sending thousands of Watch 4 wearers into a panic and overloading the health care system with meaningless alerts.

Apple’s website claims

Apple Watch Series 4 is capable of generating an ECG similar to a single-lead electrocardiogram. It’s a momentous achievement for a wearable device that can provide critical real-time data for doctors and peace of mind for you.

Apple’s “momentous achievement” was actually achieved 10 months earlier by AliveCor and if its monitoring algorithm and ECG system are significantly worse than the proven AliveCor system they will be destroying the peace of mind of users.

Electrodes built into the Digital Crown and the sapphire back crystal allow sensing of cardiac electrical signals. Did Apple get this idea from AliveCor?

After describing the Apple Watch’s new health features, Jeff Williams introduced Ivor Benjamin, MD, the President of the American Heart Association. Benjamin proceeded to describe the new Apple Watch cardiac features as “game-changing”, noting that the AHA is committed to helping patients be “proactive.”

Does  Benjamin have access to the accuracy of the Apple Watch ECG sensor? If so, he and the AHA should immediately share it with the scientific community. If not, by endorsing this feature of the Watch he should be ashamed. Users need to know if he or the AHA was paid any money for this appearance. Also, we should demand to know if (as the prominent AHA logo suggested and news reports implied) the AHA is somehow endorsing the Apple Watch.

Frequent readers know I’m a huge Apple fan but this Apple Watch business makes me think something is rotten in the state of Apple.

Skeptically Yours,

-ACP

Update On The Kardia Band Apple Watch Accessory: Accuracy In Atrial Fibrillation Pre and Post Cardioversion

As I described here, the Kardia Band (KB) is an FDA-approved Apple Watch accessory available to the general public without a prescription which records a high quality single-lead ECG.

I’ve been using mine now for a while and can confirm the ease and accuracy of the ECG recordings it makes. I find recordings made with my Apple Watch/Kardia Band are reliably high quality with minimal artifact (unless I’m running on a treadmill.)

Once the 30 second recording is completed, the Kardia app on the Apple Watch takes about 5 seconds to process the information using an AI algorithm and then makes a determination of normal sinus rhythm (NSR), atrial fibrillation or unclassified.

 

 

The New Study

A study published in the June JACC examined the accuracy of  Alivecor’s Kardia Band in detecting atrial fibrillation (AF.)

In the JACC study, investigators from the Cleveland Clinic studied  100 consecutive patients presenting for cardioversion from AF with recordings made before  and after the procedure. KB interpretations were compared to 12 lead ECGS read by electrophysiologists.

KB interpretations  identified AF with  93% sensitivity and 84% specificity. Of the total 169 recordings, 34% were unclassified due to short recordings, low-amplitude p waves, and baseline artifacts.

The authors concluded that the KB algorithm for AF detection, when it is supported by a physician review can reliably differentiate AF from NSR.

(Of note the lead author on this study is on the advisory board of Alivecor the maker of the KB and AliveCor (AliveCor, Mountain View, CA) provided the Kardia Band monitors which were connected to an Apple Watch and paired via Bluetooth to a smartphone device for utilization in the study. AliveCor was not involved in the design, implementation, data analysis, or manuscript preparation of the study.)

My Updated Kardia Experience

I have found the standard Kardia device to be immensely helpful in the management of my afib patients before and after cardioversions (see my prior description here). The paper mentions that 8% of these pre-cardioversion patients showed up for the procedure in normal sinus rhythm, noting that

For each of these patients, the automated KB algorithm did not erroneously identify AF, and the physician interpretation of the KB recording correctly confirmed SR in each case.

Needless to say, it is better to find out a cardioversion is not needed before the patient shows up for the procedure. I would estimate this happens about 5-10% of the time in my practice.

The Kardia device or the KB is also really helpful post cardioversion. If the patient makes daily recordings (which I can review on Kardia Pro online) h/she and I know exactly how long sinus rhythm persisted before reverting back to AF.

This is important information which impacts future management decisions.

Kardia Band Versus Standard Kardia Device

None of my patients have purchased the Kardia Band most likely due to the cost and the fact that they don’t have an Apple Watch. If you have an Apple Watch and want to monitor your heart rhythm I think the KB is a good choice. Otherwise, the original AliveCor mobile ECG device continues to do a fantastic job (in conjunction with Kardia Pro, see here).

The combination of Kardia and Kardia Pro has substantially reduced my use of expensive and annoying long term monitors in my AF population.

In my next update on the KB I will share a reader’s real world description of the pros and cons of the KB (with Smart Rhythm monitoring) in a patient post cardioversion for AF.

Skeptically Yours

-ACP

Is It Safe To Consume Grapefruit If You Take The Blood Thinner Apixiban (Eliquis)?

A patient of mine with atrial fibrillation taking the blood thinner eliquis told me that she had eaten grapefruit for two days in a row and then developed a nose bleed. She had heard of the interaction between grapefruit and certain medications and wondered if this had caused her nose bleed.

I was unaware of any eliquis/grapefruit interaction but thought this was a remarkably astute observation and question and set about to research it properly.

Among other things, I discovered that some researchers believe the grapefruit-drug interaction to be a widespread , underreported and  highly significant problem while others feel it is overblown and a rare cause of clinically important side effects.

For those, who prefer not to delves into the gory details I give you the crux of what BMS/Pfizer, the makers of apixiban (Eliquis) told me and with which I agree:

When consumed in usual dietary volumes, grapefruit juice is considered a moderate inhibitor of CYP3A4. Therefore a dose adjustment of apixaban is not expected to be required.

In other words, although not formally studied, there is no evidence that apixiban levels are increased by moderate grapefruit juice ingestion to a degree that would cause significant bleeding complications.

Although multiple sites on the internet (including the unreliable Web MD) will tell you of a potentially dangerous interaction between grapefruit and apixiban this theoretical interaction has not proven clinically significant.

Interactively Yours,

-ACP

Below is the full text of the letter BMS sent me

Bristol-Myers Squibb and/or Pfizer have not conducted any studies evaluating the concomitant use of apixaban and grapefruit juice. The decision to prescribe apixaban in patients who are concomitantly taking grapefruit juice is a clinical decision for the treating physician based on the individual’s circumstances and inaccordance with the full prescribing information for apixaban.

While in vitro data indicates grapefruit juice can inhibit both cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp), clinical evidence suggests that grapefruit juice mediated interactions would be primarily due to the inhibition of CYP3A4 and the contribution of P-gp inhibition may be limited.1, 2 When consumed in usual dietary volumes, grapefruit juice is considered a moderate inhibitor of CYP3A4.1 Therefore a dose adjustment of apixaban is not expected to be required.

Apixaban is eliminated from the body through multiple pathways, with approximately 25% of the administered dose recovered as metabolites. The main metabolic pathway for apixaban is through CYP3A4/5, with minor contributions from other CYP isoenzymes. Apixaban is also a substrate of transport proteins P-gp and breast cancer resistance protein.3

  1. [1]  Hanley MJ, Cancalon P, Widmer WW,et al. The effect of grapefruit juice on drug disposition. Expert Opin Drug Metab Toxicol. 2011; 7(3):267-286.
  2. [2]  Farkas DG and Greenblatt DJ. Influence of fruit juices on drug disposition: discrepancies between in vitro and clinical studies. Expert Opin Drug Metab Toxicol. 2008;4(4):381-393.
  3. [3]  Eliquis® (apixaban) Package Insert. Bristol-Myers Squibb Company, Princeton, NJ and Pfizer Inc, New York, NY