External applicability of the ISCHEMIA trial: an analysis of a prospective, nationwide registry of patients with stable coronary artery disease

Aims: We sought to assess the proportion of patients eligible for the ISCHEMIA trial and to compare the characteristics and outcomes of these patients with those without ISCHEMIA inclusion or with ISCHEMIA exclusion criteria in a contemporary, nationwide cohort of patients with stable coronary artery disease (CAD). Methods and results: Among the 5,070 consecutive patients enrolled in the START registry, 4,295 (84.7%) did not fulfil the inclusion criteria (ISCHEMIA-Not Included or ISCHEMIA-Unclassifiable), 582 (11.5%) had exclusion criteria (ISCHEMIA-Excluded), and the remaining 193 (3.8%) were classified as ISCHEMIA-Like. At one year, the incidence of the primary outcome, a composite of death from cardiovascular (CV) causes, myocardial infarction (MI), or hospitalisation for unstable angina and heart failure, was 0.5% in the ISCHEMIA-Like versus 3.3% in other patients (p=0.03). The composite secondary outcome of CV mortality and MI occurred in 0.5% of the ISCHEMIA-Like patients and in 1.4% of the remaining patients (p=0.1). Conclusions: In a contemporary real-world cohort of stable CAD patients, only 4% resulted in being eligible for the ISCHEMIA trial. These patients presented an extremely low annual risk of adverse events, especially when compared with other groups of stable CAD patients.