J Transcat Intervent.2020;28:eA202005.
Comment on: Initial Invasive or Conservative Strategy for Stable Coronary Disease (ISCHEMIA) clinical trial
Fernando Mendes Sant’Anna
, Lucas Bonacossa Sant’Anna
, Sérgio Lívio Menezes Couceiro
DOI: 10.31160/JOTCI202028A202005
Much has been researched on the treatment of chronic coronary artery disease (CAD).– The ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial had been long awaited, in the hope that it would answer many remaining questions. Our purpose is to prepare a critical analysis of this document, analyzing its methodology, its results and how it may impact the cardiologist’s clinical practice.
Initially, when examining the methodology, a difference is noted between what was planned regarding sample size and what was actually accomplished. The sample size was initially calculated to detect an 18% difference in the event rate, when comparing the Invasive Strategy (INV Group) and the Conservative (CON Group) groups over a 4-year period, assuming an event rate of 20% in the second group. In other words, with an event rate of 16.4% in the INV Group, considering a test power of 90% and an alpha error of 0.05, approximately 2,500 patients would be required in each group.
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