Outcomes According to Coronary Revascularization Modality in the ISCHEMIA Trial

In the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial, the risk of ischemic events was similar in patients with stable coronary artery disease treated with an invasive (INV) strategy of angiography and percutaneous coronary intervention (PCI) or surgical (coronary artery bypass grafting [CABG]) coronary revascularization and a conservative (CON) strategy of initial medical therapy.

The authors analyzed separately the outcomes of INV patients treated with PCI or CABG.

Patients without preceding primary outcome events were categorized as INV-PCI or INV-CABG from the time of revascularization. The ISCHEMIA primary outcome (composite of cardiovascular death, protocol-defined myocardial infarction or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest) was used.

Among INV-CABG patients, primary outcome events occurred in 84 of 512 (16.4%) at a median follow-up of 2.85 years; 48 events (57.1%) occurred within 30 days after CABG, including 40 procedural MIs. Among INV-PCI patients, primary outcome events occurred in 147 of 1,500 (9.8%) at median follow-up of 2.94 years; 31 of which (21.1%) occurred within 30 days after PCI, including 24 procedural MIs. In comparison, 352 of 2,591 CON patients (13.6%) had primary outcome events at a median follow-up of 3.2 years, 22 of which (6.3%) occurred within 30 days of randomization. The adjusted primary outcome risks were higher after both CABG and PCI within 30 days (HR: 16.25 [95% CI: 11.44-23.07] and HR: 2.99 [95% CI: 1.97-4.53]) and lower thereafter (0.63 [95% CI: 0.44-0.89] and 0.66 [95% CI: 0.53-0.82]).

In ISCHEMIA, early revascularization by PCI and CABG was associated with higher early risks and lower long-term risks of cardiovascular events compared with CON. The early risk was greatest after CABG, owing to protocol-defined procedural MIs.