Kerala

Understanding ISCHEMIA trial and after

Cardiologists say though medical management may suit stable patients, in acute cases, the choice is angioplasty

It certainly cannot be a happy situation for a clinician in a busy casualty when a patient with a history of diabetes, brought in with acute chest pain in the middle of the night, and showing elevated troponin (cardiac marker) levels, turns around and questions the doctor, “Do I really need an angiography? I read recently that angioplasty is unnecessary...”

Given the speed and enthusiasm with which the results of ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) has been splashed across the media, the above scenario is something that many cardiologists here dread, especially when ‘over medicalisation’ is the buzz word.

ISCHEMIA studied patients with stable coronary heart disease due to ischemia (reduced supply of blood to heart muscles because of blocked arteries).

Investigators at 320 sites in 37 countries, including India, randomly selected 5,179 stable patients, who were found to be having moderate or severe ischemia.

One group was treated with percutaneous coronary intervention (PCI or angiography with stent) as well as optimal medical therapy (OMT), a combination of medicines and lifestyle modifications to reduce risk factors. Another group was treated only using OMT. At the end of 3.3 years, it was found that there was no overall difference between the two groups in the rates of cardiovascular death or heart attack.

Instances of hospitalisation for unstable angina (chest pain), heart failure and resuscitation after cardiac arrest were also similar in both groups.

In the U.S., where almost every other patient with a coronary block ends up in the Cath lab, the trial results have been hailed as “practice-changing.”

Cardiologists in India are, however, more moderate in their response and point out that ISCHEMIA has only confirmed what is already known. That, for stable coronary artery disease (CAD), angioplasty is not a lifesaver. The removal of arterial blocks might give symptomatic relief to a stable CAD patient, but it does not “fix” the future risk of heart attacks.

However, headlines such as “Meds work as well as invasive surgery for heart disease” have drummed up enough excitement among the public that people could be misled into thinking that angioplasty is “useless”, fears Tiny Nair, a senior consultant cardiologist.

In acute cases

“The public need to be told clearly that for any acute coronary event like a heart attack, the choice of treatment is always angioplasty. But if you are a stable CAD patient, ie, despite having a block you do not have many symptoms, you can very well be managed on medical therapy,” says Dr. Nair.

Today, about 30% of the interventional procedures are done in people with stable CAD. While PCI procedures are not considered life-saving in this category, doctors cannot be faulted for wanting to remove the blocks because PCI does relieve their chest pain and give patients a better quality life, says V. K. Ajitkumar, Professor of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, who had been part of ISCHEMIA.

In fact, ISCHEMIA had also reported that patients with symptoms of angina who underwent PCI were angina-free and had a better quality of life through the study period.

Pertinently, at the end of 3 years, 23% of patients in the OMT arm of the trial had crossed over to the PCI group, as their disease could not be managed by medical therapy alone.

“ISCHEMIA proved that for a heart patient who has stable disease, there is always room for medical management and lifestyle modification before attempting invasive procedures. But to prevent missing high-risk cases who might need PCI, a CT-guided or a standard coronary angiogram may be performed to reach a final decision,” Dr. Ajitkumar says.

The take home message is clear: medical management or a PCI may not be the final answer to prevent acute coronary events in future, which will always depend on the patient’s burden of atherosclerosis. Hence, there is no harm in trying the medical management route first. However, if the symptoms persist, the clinician and the patient should discuss about revascularisation.

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Printable version | Feb 18, 2020 11:55:04 AM | https://www.thehindu.com/news/national/kerala/ischemia-trial-and-after/article30091026.ece

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