Science continued to progress in the field of cardiology in 2017. Some cardiology interventions were proven to be more beneficial (TAVR) and some less (coronary stents). A class of cholesterol lowering drugs had a big winner and a big loser. A supplement that many thought, based on observational studies, was crucial to prevent heart disease, turned out to be unhelpful. More evidence emerged that saturated fat is not a dietary villain.
From the skeptical cardiologist’s viewpoint, the following were the major scientific studies relevant to cardiology:
1. “Thousands of heart patients get stents that may do more harm than good”
Indeed this was an earth-shattering study for interventional cardiologists, many of whom agreed with the NY Times headline “Unbelievable: Heart Stents Fail To Ease Chest Pain.”
Cardiologists have known for a decade (since the landmark COURAGE study) that outside the setting of an acute heart attack (acute coronary syndrome or ACS), stents don’t save lives and that they don’t prevent heart attacks.
Current guidelines reflect this knowledge, and indicate that stents in stable patients with coronary artery disease should be placed only after a failure of “guideline-directed medical therapy.” Despite these recommendations, published in 2012, half of the thousands of stents implanted annually in the US continued to be employed in patients with either no symptoms or an inadequate trial of medical therapy.
Yes, lots of stents are placed in asymptomatic patients. And lots of patients who have stents placed outside the setting of ACS are convinced that their stents saved their lives, prevented future heart attacks and “fixed” their coronary artery disease. It is very easy to make the case to the uneducated patient that a dramatic intervention to “cure” a blocked artery is going to be more beneficial than merely giving medications that dilate the artery or slow the heart’s pumping to reduce myocardial oxygen demands.
Stent procedures are costly in the US (average charge around $30,000, range $11,000 to $40,000) and there are significant risks including death, stroke and heart attack. After placement, patients must take powerful antiplatelet drugs which increase their risk of bleeding. There should be compelling reasons to place stents if we are not saving lives.
I, along with the vast majority of cardiologists, still recommended stents for those patients with tightly blocked coronary arteries and stable symptoms, which were not sufficiently helped by medications. ORBITA calls into question even this indication for stenting.
The ORBITA study investigators recruited 230 patients to whom most American cardiologists would have recommended stenting. These patients appeared to have a single tightly blocked coronary artery and had chest pain (angina) that limited their physical activity.
They treated the patients for 6 weeks with aspirin/statins/ and medications that reduce anginal symptoms such as beta-blockers, calcium-channel blockers or long-acting nitrates. At this point patients were randomized to receive either a stent or to undergo a catheteriation procedure which did not result in a stent, a so-called sham procedure.
The performance of a sham procedure was a courageous move that made the study truly double-blinded; neither the patients nor the investigators knew which patients had actually received a stent. Thus, the powerful placebo effects of having a procedure were neutralized.
Surprisingly, the study found that those patients receiving stents had no more improvement in their treadmill exercise time, angina severity or frequency or in their peak oxygen uptake on exercise.
ORBITA hopefully will cause more cardiologists to avoid the “oculo-stenotic” reflex wherein coronary artery blockages are stented without either sufficient evidence that the blockage is causing symptoms or that a medical trial has failed.
Although this was a small study with a very narrowly defined subset of patients, it raises substantial questions about the efficacy of coronary stenting. If ORBITA causes more patients and doctors to question the need for catheterization or stenting, this will be a very good thing.
2. Vitamin D Supplementation Doesn’t Reduce Cardiovascular Disease (or fractures, or help anything really).
One of my recurring themes in this blog is the gullibility of Americans who keep buying and using useless vitamins, supplements and nutraceuticals, thereby feeding a $20 billion industry that provides no benefits to consumers (see here and here).
Vitamin D is a prime player in the useless supplement market based on observational studies suggesting low levels were associated with increased mortality and cardiovascular disease
Despite well done studies showing a lack of benefit of Vitamin D supplementation, the proportion of people taking more than 1,000 IU daily of Vitamin D surged from just 0.3 percent in 1999-2000 to 18 percent in 2013-2014.
I’ve written previously (calcium supplements: would you rather a hip fracture or a heart attack) on the increased risk of heart attack with calcium supplementation.
Most recently a nicely done study showed that Vitamin D supplementation doesn’t reduce the risk of heart disease.
In a randomized clinical trial that included 5108 participants from the community, the cumulative incidence of cardiovascular disease for a median follow-up period of 3.3 years was 11.8% among participants given 100 000 IU of vitamin D3 monthly, and 11.5% among those given placebo.
Aaron Carroll does a good job of summarizing the data showing Vitamin D is useless in multiple other areas in a JAMA forum piece:
Last October, JAMA Internal Medicine published a randomized, controlled trial of vitamin D examining its effects on musculoskeletal health. Postmenopausal women were given either the supplement or placebo for one year. Measurements included total fractional calcium absorption, bone mineral density, muscle mass, fitness tests, functional status, and physical activity. On almost no measures did vitamin D make a difference.
The accompanying editor’s note observed that the data provided no support for the use of any dose of vitamin D for bone or muscle health.
Last year, also in JAMA Internal Medicine, a randomized controlled trial examined whether exercise and vitamin D supplementation might reduce falls and falls resulting in injury among elderly women. Its robust factorial design allowed for the examination of the independent and joined effectiveness of these 2 interventions. Exercise reduced the rate of injuries, but vitamin D did nothing to reduce either falls or injuries from falls.
In the same issue, a systematic review and meta-analysis looked at whether evidence supports the contention that vitamin D can improve hypertension. A total of 46 randomized, placebo controlled trials were included in the analysis. At the trial level, at the individual patient level, and even in subgroup analyses, vitamin D was ineffective in lowering blood pressure.
Finally, if the Vitamin D coffin needs any more nails, let us add the findings of this recent meta-analysis:
calcium, calcium plus vitamin D, and vitamin D supplementation alone were not significantly associated with a lower incidence of hip, nonvertebral, vertebral, or total fractures in community-dwelling older adults.
3. PCSK9 Inhibitors: Really low cholesterol levels are safe and reduce cardiac events
I reported the very positive results for evolocumab and disappointing results for bosocizumab on the physician social media site SERMO in March but never put this in my blog.
As a practicing cardiologist I’ve been struggling with how to utilize the two available PCSK9 inhibitors (Amgen’s Repatha (evolocumab) and Sanofi’s Praluent (alirocumab) in my clinical practice. I would love to use them for my high risk statin-intolerant patients but the high cost and limited insurance coverage has resulted in only a few of my patients utilizing it.
The lack of outcomes data has also restrained my and most insurance companies enthusiasm for using them.
The opening session at this year’s American College of Cardiology Scientific Sessions in DC I think has significantly changed the calculus in this area with two presentations: the first showing Amgen’s “fully humanized” evolocumab significantly lowers CV risk in high risk patients on optimal statin therapy and the second showing that Pfizer’s “mostly humanized” bococizumab loses efficacy over time and will likely never reach the market.
The FOURIER study of evolocumab randomized 27, 564 high risk but stable patients who had LDL>70 with prior MI, prior stroke or symptomatic PAD to receive evolocumab or placebo on top of optimized lipid therapy. 69% of patients were recieving high intensity statin therapy and the baseline LDL was 92. LDL was reduced by 59% to average level of 30 in the treated patients. The reduction in LDL was consistent through the duration of the study.
IN 1/4 of the patients LDL was <20! These are unprecedented low levels of LDL.
Active treatment significantly reduced the primary endpoint by 15% and reduced the secondary endpoinf of CV death, MI, stroke by 20%. absolute difference 2% by 3 years.
There was no difference in adverse effects between placebo and Evo.
The next presentation featured data using Pfizer’s candidate in the PCSK9 wars and the acronym SPIRE (Studies of PCSK9 Inhibition and the Reduction in vascular Events (SPIRE) Bococizumab Development Program).
Paul Ridker presented the outcomes data for bococizumab which was actually similar to evolocumab data but given the declining efficacy and development of antibodies to the Pfizer drug over time these were very disappointing for Pfizer and I would presume their drug will never reach the market.
How will these results impact clinical practice?
I am now more inclined to prescribe evolocumab to my very high risk patients who have not achieved LDL< 70. I’m willing to do what I can to jump through insurance company hoops and try to make these drugs affordable to my patients.
I am less worried about extremely low LDL levels and have more faith in the LDL hypothesis: the lower the LDL the lower the risk of CV disease.
Cost is still going to be an issue for most of my patients I fear and the need for shared decision-making becomes even more important.
4. “Pure Shakes Up Nutritional Field: Finds High Fat Intake Beneficial.”
As one headline put it.
I recorded my full observations on this observational international study here
Here is a brief excerpt:
The Prospective Urban Rural Epidemiology (PURE) study, involved more than 200 investigators who collected data on more than 135000 individuals from 18 countries across five continents for over 7 years.
There were three high-income (Canada, Sweden, and United Arab Emirates), 11 middle-income (Argentina, Brazil, Chile, China, Colombia, Iran, Malaysia, occupied Palestinian territory, Poland, South Africa, and Turkey) and four low-income countries (Bangladesh, India, Pakistan, and Zimbabwe)
This was the largest prospective observational study to assess the association of nutrients (estimated by food frequency questionnaires) with cardiovascular disease and mortality in low-income and middle-income populations,
The PURE team reported that:
-Higher carbohydrate intake was associated with an increased risk of total mortality but not with CV disease or CV disease mortality.
I particular liked what the editorial for this paper wrote:
Initial PURE findings challenge conventional diet–disease tenets that are largely based on observational associations in European and North American populations, adding to the uncertainty about what constitutes a healthy diet. This uncertainty is likely to prevail until well designed randomised controlled trials are done. Until then, the best medicine for the nutrition field is a healthy dose of humility
I wish for all those following science-based medicine a healthy dose of humility. As science marches on, it’s always possible that a procedure we’ve been using might turn out to be useless (or at least much less beneficial than we thought), and it is highly likely that weak associations turn out to be causally nonsignificant. Such is the scientific process. We must continually pay attention, learn and evolve in the medical field.
Happy New Year to Be from the Skeptical Cardiologist the EFOSC!