Leading Indian cardiologists have said that a study in The Lancet, which showed insertion of stents may not always benefit people suffering from chest pain precipitated by exertion (medically called stable angina), has neither charted new ground nor has it followed up enough patients for long enough to be a reliable commentary on stenting, or its outcome.
“It is a very superficial study. Just 200 people have been followed for six weeks — and merely on the parameter of whether they get chest pain or not,” Dr Naresh Trehan, cardiologist and chairman and managing director of Medanta, the Medicity, said.
“In any case, for a single artery blockage — provided that single vessel is not the left anterior descending artery (LAD) or one with a 90-per cent blockage — even now we are treating with medical therapy. But the study does not address the quality of life,” he said. “It is actually a very lightweight study, just dealing with people who feel chest pain if they, say, walk for a while, which (pain) goes away when they stop. “Such patients are already being treated only with medicines. It (Lancet study) does not, in any way, change the way we look at stents.”
A branch of the left coronary artery, which supplies oxygenated blood to the heart and is crucial for its function, LAD is supposed to be the most important vessel for maintenance of blood supply to the heart.
The issue of stents and their pricing is being debated in India after the National Pharmaceutical Pricing Authority capped their prices earlier this year, causing an outcry from hospitals and stent manufacturers.
According to a study published in the journal ‘Circulation’ last year, “Cardiovascular diseases (CVDs) have now become the leading cause of mortality in India. A quarter of all mortality is attributable to CVD. Ischemic heart disease and stroke are the predominant causes and are responsible for >80% of CVD deaths. The Global Burden of Disease study estimate of age-standardized CVD death rate of 272 per 100,000 population in India is higher than the global average of 235 per 100,000 population.”
One of its authors, Dr Ambuj Roy, professor of cardiology at AIIMS, who, like Dr Trehan, also does interventions, agrees that there is nothing new in the Lancet study to change the mode of treatment of stable angina, as it has always been well recognised and well-documented that stents do not have much use for such patients.
But, he said, it does not make a very important differentiation between stable angina and acute coronary syndrome. It is people suffering from the latter for whom stents can be lifesaving, he said.
“People who suddenly have a heart attack — for them, stenting is important,” Dr Roy said. “Stents were never known to improve stable angina. Where this study breaks new ground is, it is the first one to look at whether there can be a placebo effect of stenting.”
In terms of the effects of stenting, he said The Lancet report is merely a reiteration of what was revealed by the far bigger and deeper 15-year follow-up period COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) study of 2007, which showed that for stable coronary artery disease (clogged arteries nourishing the heart), artery-opening angioplasty was no better than medications and lifestyle changes at preventing future heart attacks or strokes, nor did it extend life.
Cardiologist Dr Devi Shetty of Narayana Health said, “It is already known that angioplasty, if done for non-critical lesions or single artery blockage, does not really give any benefit. But for critical lesions, angioplasty certainly makes life better. This study dealt with relatively asymptomatic patients, the follow-up period was too less. Yes, one needs to be careful when advising angioplasty…. But the distinction between symptomatic and asymptomatic patients is very crucial.”