Outcomes of patients with moderate-to-severe Ischemia excluded from the ischemia trial

Background The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial showed no difference in outcomes between medical therapy vs coronary revascularization in the management of patients with stable coronary artery disease. We aimed to determine the percentage of patients with at least moderate ischemia that would have been eligible for enrollment and evaluate the outcomes of those who would not. Methods Consecutive patients who underwent cardiac single-photon emission computed tomography (SPECT) between April 2016 and September 2019 were identified and all-cause mortality was determined. Results There were a total of 1508 patients (mean age 67 ± 11.6 years, 69.5% males) with any perfusion defect on SPECT. Patients had a high prevalence of cardiac risk factors (73.4% with hypertension and 54.4% with diabetes mellitus.) Nearly half (709, 47%) had moderate-to-severe ischemia but over two-thirds (479/709, 66.3%) had at least one ISCHEMIA trial exclusion criteria. Patients meeting ISCHEMIA enrollment criteria had a significantly lower all-cause mortality than those who would have been excluded (3.91% vs. 11.3%, respectively, P < .001). Conclusion Our results show that ISCHEMIA selected a relatively small subset of lower risk patients among the larger higher risk group of patients with moderate-to-severe ischemia typical to most cardiology centers.