To Stent or not to Stent? ISCHEMIA Trial brings Game Changers of rules of Stenting

USA: Angioplasty or CABG does not reduce the risk of death in angina pectoris in stable coronary artery disease (CAD) versus medical treatment- startling revelations to this effect have been made by the International Study of Comparative Health Effectiveness With Medical And Invasive Approaches (ISCHEMIA) trial. The trial has delivered a decisive result that invasive strategy by angioplasty or even bypass surgery does not outperform medical treatment in any major cardiovascular events including death, heart attack, and heart failure even after four years of presentation.

One of the largest trial that continued for more than 10 years and spent more than 100 million dollars is trying to answer a 365 million dollar question that whether a patient of angina pectoris should be offered stenting or bypass surgery as the primary treatment compared with the optimal medical therapy or not?

The study was conducted in 5,179 patients out of which more than 50% of patients in the trial had severe inducible ischemia at baseline, 33% had moderate, and 12% had mild ischemia and Positive TMT at the second stage of exercise strategy. The patients with left vein stenosis with severe CAD and recurrent myocardial infarction (MI) having ejection fraction within 35% and unacceptable angina at baseline were excluded. After 4 years it was noted that the serious outcomes of death, MI and heart failure occurred in a similar number of patients who were subjected to intensive medical therapy. However, angioplasty was associated with more harm in the first 6 months and more benefit after 4 years. With angioplasty, the improvement of symptoms were definite in patients having angina pectoris but not in those without angina pectoris. The above results have delivered a definite blow to the executive medical checkup with routine stress testing.

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The results have been taken up with cautious comments from various experts.

Dr. Vijay Trehan, professor of Interventional cardiology at G.B. Pant Hospital said “ The ISCHEMIA trial has only confirmed the finding of COURAGE Trial which suggested that revascularization should be only offered to only the patients having definite indications of ISCHEMIA and symptoms of angina. In this trial once again, invasive therapy has failed to reduce major adverse cardiovascular events (MACE) in patients with less ischemia.

However, with the patients having a high degree of ischemia burden like left main disease and proximal CAD or having an impact of severe ischemia in the form of reduced ejection fraction and development of ischemic cardiomyopathy, revascularization should be of immense value. Unfortunately, these are the patients who are more likely to benefit from revascularization are usually not investigated for the existence and impact of CAD and are denied the treatment.”

This particular trial has only confirmed that an interventionist should choose their patients more judiciously and just because a particular procedure can be easily done, it should not be the criteria for undertaking the same in all patients.

Judith Hochman, who led the study, presented the study at the American Heart Association (AHA) 2019 annual meeting.

One more definite suggestion from this trial comes to the supporters of CT-angiography – In this trial, 434 patients were excluded from the trial because the patients had left main disease and 1.218 patients were excluded from the trial because they did not have any obstructive disease despite symptoms. That simply means that while stress testing does not confidently identify the patients who will benefit from revascularisation CT-angioplasty can be extremely useful in guiding the rule-in and rule-out of revascularization.

If you act on ISCHEMIA and say I will treat all my patients on medical treatment and treat only if angina does not go away or angina increases on medical treatment then without CT-angiography you will be missing the patients of left main disease who have a higher risk of dying in such a case. This suggested that some form of angiography whether CT or invasive shall be necessary to put the patients on medical treatment and ruling out an invasive intervention.