ISCHEMIA Shows Medical Therapy Outcomes As Good As Coronary Stents or Bypass For Most CAD Patients

The ISCHEMIA (International Study of Comparative Health Effectiveness With Medical And Invasive Approaches) study presented at the AHA meeting this week provides further evidence that a conservative approach utilizing optimal medical therapy is an acceptable strategy for most patients with stable coronary disease (CAD).

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), coronary 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 stabilize atherosclerotic plaque, dilate the coronary artery or slow the heart’s pumping action 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.

What Did ISCHEMIA Prove?

ISCHEMIA (paper unpublished but slides available here) showed that an invasive strategy (employing cardiac catheterization with resulting stenting or coronary bypass surgery (CABG)) offered no benefit over optimal medical therapy in preventing cardiovascular events in patients with moderate to severe CAD.

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Rates of all-cause death were nearly superimposable over the years studied, reaching 6.5% and 6.4% at 4 years for the invasive and conservative groups,

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Inclusions and exclusion criteria are listed below. Patients with unnaceptable angina despite optimal medical therapy were not included. These patients clearly benefit symptomatically from revascularization (as long as their chest pain is actually angina and not from another cause.)

All patients had stress imaging studies demonstrating moderate to severe amounts of ischemia. Such patients with very abnormal stress tests in the past have typically been sent immediately to the cath lab.

Based on ISCHEMIA we now know in these patients there is no need to do anything urgently other than institute OMT.

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These patients were on good medical therapy which likely explains the very good outcomes in both conservative and invasive arms. The “high level of medical therapy optimization” is what cardiologists should be shooting for with LDL<70, on a statin with systolic blood pressure <140 mm Hg, on an antiplatelet drugg and not smoking.

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Interestingly coronary CT angiography (CCTA) was utilized prior to patients receiving catheterization. I’ve been  utilizing this noninvasive method for visualizing the coronary arteries increasingly prior to committing to an invasive approach.

Quality Of Life 

Finally, in a separate presentation the ISCHEMIA trial showed that the invasive strategy did improve symptoms and quality of life modestly. It did not improve quality of life in those without angina symptoms.

The ORBITA study (which I wrote about here) showed that a large amount of the symptomatic improvement in patients following stenting may be a placebo effect.

Importance Of ISCHEMIA

Hopefully the results of ISCHEMIA will cut down on the number of unnecessary catheterizations, stents and bypass operations performed. This, in turn, will save our health system millions of dollars and prevent unnecessary complications.

Outside the setting of an acute heart attack the best approach to patients with blocked coronary arteries is a calm, thoughtful, and measured one which allows ample time for shared decision-making between informed patients and knowledgeable physicians. Such decisions should carefully consider the ISCHEMIA, COURAGE and ORBITA results.

Nonischemically Yours,

-ACP

N.B. Ischemia is a fantastic acronym for this study. Doctors use it a lot to describe the absence of sufficient blood flow to tissues.

N.B.2 Although I deplore the number of unnecessary caths and stents performed in the US, especially in patients without symptoms and those with noncardiac chest pain, I still utilize them in my patients with flow-limiting coronary stenoses and unacceptable anginal chest pain with symptoms despite optimal medical therapy and have noticed outstanding results. This angiogram shows a tight, eccentric LAD blockage in such a patient who now, post stent, has had complete resolution of the chest pain that limited him from even short walks.

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16 thoughts on “ISCHEMIA Shows Medical Therapy Outcomes As Good As Coronary Stents or Bypass For Most CAD Patients”

  1. Hello, Dr P. I am obviously very pleased with my results and quality of life since my quintuple bypass surgery more than 7 years ago. You may recall that I had had a couple episodes of chest pain but no evidence of an actual heart attack and have no regrets about our treatment plan. But I am curious if this report suggests that if my symptoms presented today we might have taken a different course. Thx.

  2. Is your above blog article telling me I probably didn’t need my stent? Not intending to be flippant, but my question is pretty much the same as John Crotty’s before. I will tell you that I seemed to be doing better after the stent but a short while later (couple weeks perhaps when I actually got into my rehab program) I began experiencing chest pain during treadmill workou. Isosorbide mononitrate was prescribed and suddenly I’ve got the energy I had some ten years ago and earlier. My BP runs very low anyway, so I have to be careful as the Imdur lowers it further. Anyway, nothing to be done about the existing stent, but this is good to know that I may never need another one, though I’ll have to live with the nitrate, antiplatelet and cholesterol meds and the attendant colorful bruises.

    1. P.S. Just read the NYT article of the 16th on this. This stood out re the Ischemia study: “The participants in Ischemia were not experiencing a heart attack, like Senator Bernie Sanders, nor did they have blockages of the left main coronary artery, two situations in which opening arteries with stents can be lifesaving. Instead, the patients had narrowed arteries that were discovered with exercise stress tests.” My stent is to the LAD.

      1. Yes. Stents in the setting of acute MI (heart attack) are life saving. The NYT article is somewhat blurring the truth when it implies left main blockage is best treated by stents. Left main blockage >50% is best treated by bypass surgery. One of the purposes the coronary CT angio served in ISCHEMIA was to exclude left main.

        1. I just got diagnosed yesterday with CAD following a negative stress echocardiogram, scheduled due to sudden onset of PVC (or AVC: I keep getting a differenct story) and chest pain following sustained exertion). I think (but am not confident that) the diagnosis was LMA blockage and a (possible urgent) PCI has been scheduled for Tuesday. The lack of “a calm, thoughtful, and measured [conversation] which allows ample time for shared decision-making” concerns me a lot–it’s partly my fault b/c I was not feeling very calm! And I’ll be making a phone call on Monday morning and probably seeking a second opinion. Here’s my question: the ISCHEMIA study demonstrates that GDMT is as effective as PCI for most patients. However, as you indicate at the end of your post, they specifically excluded LMA blockage and in section 5 state that either PCI or CABG are preferable treatments for LMA. However, the final paragraph of 5.12.1 (“women”) claims that that for women, GDMT therapy should be pursued before revascularization. Am I understanding that correctly? Thanks, Christina (P.S. The PA did prescribe Imdur, Lopressor, and aspirin, all of which I have begun taking. I myself rather recklessly declined the statin: will correct asap).

          1. Christina,
            Can you copy the relevant paragraphs you are asking about into a comment?
            I am not aware of this differentiation based on gender and would not to research where it comes from.
            Obviously, I can’t comment or make recommendations on your case but in general determining the degree of blockage/stenosis in the left main is tricky from invasive coronary angiography (ICA).
            Depending on which cardiologist is viewing the ICA you can get wildly varying estimates of the degree of stenosis. To improve assessment, invasive cardiologists sometimes use intravsclar ultrasound or FFR.
            This paper discusses it in more and more interesting detail.
            About the size of the average cigarette butt, the left main coronary artery is a relatively small vessel, yet it is arguably 1 of the most valuable sections of real estate within the body. Since Herrick’s description 100 years ago, we are well aware of the lethality of left main disease (1). Stenosis of the left main coronary is 1 of the few, specific coronary lesions in which revascularization reduces the likelihood of death compared with medical therapy (2–4). Thus, seeking out and revascularizing left main disease has become established as 1 of the tenets of modern cardiology.
            See page 1021
            Identification of significant left main disease is not always easy. Angiography routinely underestimates and overesti- mates the degree of left main narrowing. This is particularly true for ostial, distal bifurcation, and diffusely diseased segments or in the presence of dense calcium or eccentric disease (Fig. 1). Wary of missing a potentially lethal condi- tion, clinicians tend to “overcall” lesions and refer patients for bypass surgery who might not actually have significant stenosis. When this happens, grafts may occlude or become atretic (5). Thus, there are consequences to both missing the diagnosis as well as overestimating disease severity. It is really important to get this right.
            Adjunctive methods, including fractional flow reserve (FFR) and intravascular ultrasound (IVUS), have been employed in the assessment of ambiguous left main lesions (6–12). For IVUS, minimal luminal area (MLA) is mea- sured; the cutoff value defining significance is not entirely clear. The lower range for a normal left main stem is 7.5 mm2 (6). An MLA 􏰀5.9 mm2 has been shown to correlate with an ischemic FFR in 1 study (7), but in another study, an MLA 􏰀4.8 mm2 best predicted FFR 􏰀0.80 (8)

            1. Thanks for responding! i am not looking for medical advice but rather making sure that I understand the basic conclusions. I’m a pretty good reader but my goodness this is some complicated stuff! From the ISCHEMIA study: “The risk of procedural complications also ap- pears to be significantly higher in women.1149 Although fewer data on the experience of women after CABG are available, in the New York State registry, the odds of in-hospital death for women were 2-fold higher than for men.1149,1150 On the basis of these observations, the initial approach to therapy for women with SIHD should be to prescribe a full regimen of GDMT and to reserve consideration of revascularization for patients who do not obtain a satisfactory response or who experience unacceptable adverse effects. On the basis of the higher risk associated with PCI in women, it might be reasonable to adopt a more conservative approach in under- taking this procedure than in men, although the general principle of using revascularization in patients whose symp- toms are refractory to medical therapy and who are not satisfied with their current level of angina persists.” Section 5.12.1, page e423

              1. In case I’m not being clear about my source: 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease

              2. Christina,
                I thought you were implying specific gender differences in treatment of left main but these comments from the 2012 guidelines for stable ischemic heart disease don’t really mention left main. I agree with the general concept that women are at higher risk for complications and we should have higher thresholds for intervention due to that higher risk.
                In someone who has had a normal stress test with imaging without any high risk features from the treadmill strest test I am suspicious of the diagnosis of left main which, as I indicated in the previous comment, is frequently overcalled and is best confirmed by another modality. in ISCHEMIA they utilized CCTA

                1. OK. I see. Thanks for pointing that out. Would it be appropriate for me to ask for CCTA prior to going forward with the PCI?

  3. Stents and CABG to not prevent further progression of CAD and no patient should be led to believe that they do. If you have a stent placed and don’t change your life style, you will end up eventually right where you started. Atherosclerosis is a life style disease of developed countries and populations such as South Asians. I agree with the doctor that there are stents placed in non-symptomatic patients which are costly and unnecessary. If you have symptomatic angina you are a victim of easy living. By easy living I mean low physical activity, high fat, high cholesterol diet, smoking, obesity, excessive alcohol use or abuse. Ain’t nothing gonna turn that around except YOU.

    1. Not always true. I don’t smoke or drink and exercise daily. I eat nothing but fruits, vegetables, fish, whole grains – and am the perfect weight for my height. Some of us are just born with bad genes as heart disease runs rampant in my family. It’s nice that you are so perfect but some of us have to deal with the hand we are dealt with.

      1. As I said above, people like us need to be even more vigilant. Also, at least we know what we’ve got and the medication available does help us–at least it has greatly helped me and hope whatever you and your doctor are doing helps you.

    2. Ditto if you happen to be unlucky enough to have inherited some undesirable genes but thought you have been living [mostly] right. Just have to be even more stringent in adhering to very healthy diet and lifestyle.

  4. Do you look for collateral vessels that might be bridging blockages when you do angiography? It’s my understanding that these small vessels are difficult to visualize with standard methods.

    If not, when you do a bypass (or refer for one) mightn’t you unknowingly destroy these vessels that, in their numbers, may have obviated the need for that bypass?

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