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Arterial Disease

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 Angioplasty Disappointment?

No group of diseases has received more attention than diet-related arterial disease. No other diseases have received more drug promotion and educational effort both from government agencies and from private fund-raising organizations such as the American and Canadian Heart Associations. The rule in cardiovascular medicine is that all current practices and beliefs will change. The one constant is the diet revision and exercise cure all ills. You can fool some diseases some of the time, but not all diseases all the time. We continue to champion the simple idea that removing the cause of the disease is smarter than treating the effects.

One of the key innovations in heart attack prevention was unplugging blocked arteries by cardiac catheterization and angioplasty also known as Percutaneous Coronary Interventions (PCI). A catheter is inserted into the femoral artery in the groin and guided through the aorta into the coronary arteries. Injected dye shows the arteries on X-rays and the catheter is guided to sites of obstruction. A balloon is inflated to dilate the blocked artery and a metal stent is left behind to hold the artery in an expanded position. Bare metal stents were associated with recurrent arterial blockage months to years after. Drug eluting stents were developed using anti-inflammatory agents that reduce restenosis but cost three times more. Anticoagulants are used to reduce the risk of stent thrombosis. Vitamin K antagonists (VKAs) have been the main choice now replaced by new anticoagulants that act directly on clotting factors (direct oral anticoagulants -DOACs). Bleeding in patients taking traditional oral anticoagulants is a risk. The most devastating complication of VKA treatment is intracranial hemorrhage/hemorrhagic stroke, Bleeding remains a risk of taking DOACs.

The enthusiasm for PCI and drug-eluting arterial stents (DES) peaked in 2006. Drug coated stent sales generated $6 billion in the USA. Follow-up studies have raised doubt about the safety of DES. According to Kaul and Diamond: “Thus, in the absence of a definitive trial, based on the reported estimate of 0.6% excess late stent thrombosis per year, and the attendant case fatality rate of 45%, we nevertheless estimate that using DES in 80% out of 1 million percutaneous coronary intervention cases would translate into 2,160 excess deaths per year attributable to late stent thrombosis in the United States alone.”

The results of a large study reported at the American Cardiology Conference in New Orleans March 2007 that people with coronary artery disease who are treated with diet, exercise and optional drugs do as well as patients who had a angioplasty to unblock clogged arteries.

Boden et al stated: “Although successful PCI of flow-limiting stenosis might be expected to reduce the rate of death, myocardial infarction, and hospitalization for acute coronary syndromes, previous studies have shown only that PCI decreases the frequency of angina and improves short-term exercise performance.” They concluded that preventive PCI in patients with CAD with did not reduce the risk of death, myocardial infarction, or other major cardiovascular events when added to optimal medical therapy.

The value of stents was again negated by the ORBITA study published in the Lancet, 2017 that showed that among people with severe blockage of the coronary arteries, the procedure did not improve angina—the reason for nearly 500,000 PCI procedures worldwide every year—or ability to exercise on a treadmill. Now after 40 years, millions of procedures, and billions of dollars, doctors are questioning whether the common procedure is, in most nonemergency cases, doing much less good than previously believed, if any. [i]To discard the findings from ORBITA indicates hubris—a doctor's greatest enemy.

Intervention cardiologist John Mandrola summarized a good response to ORBITA’s findings:” It's also wrong to overextend these findings to unstable patients or to focus only on overuse of PCI. Overuse is a problem, but I see two broader messages from this study. One is to respect the placebo and nocebo effect. Our ability to help or harm people with our words and actions gets too little attention. We think our procedures help people, and they clearly do, but how often is it simply our caring and effort that delivers most of the benefit? The other, and perhaps most lasting message from ORBITA, is that it could force a rethinking of the stenosis-centric frame for treating CAD. For decades, cardiologists feared focal lesions because they cause ischemia. PCI relieves ischemia. So PCI is good. Then COURAGE came along. We understood it, we accepted it, but we didn't really believe it. And we didn't have to, we had an out: a stent may not reduce the rate of MI or death, but it relieved human suffering. Now that ORBITA has cast great doubt on this last promise of PCI in stable CAD, maybe we can—finally—start to see atherosclerosis in a new way. And if that happens, if we get out of the frame of mind that progress means building a better way to fix blockages, who knows what new treatment for heart disease could be discovered?”  [ii]


[i] ORBITA: Sham Comparison Casts Doubt on PCI for Stable Angina - Medscape - Nov 03, 2017.
[ii] John Mandrola. Coronary Stents Humbled Yet Again in Stable CAD. Why ORBITA Could Be Good News for Cardiology. Medscape November 07, 2017

 

Kaul, S. Diamond GA. Drug-Eluting Stents: An Ounce of Prevention for a Pound of Flesh? Amer Coll Cadiology, Cardioscope, Online 10/11/2006

Boden W.E. et al Optimal Medical Therapy with or without PCI for Stable Coronary Disease. NEJM March 26 2007


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