Asymptomatic Cardiac Ischemia Pilot (ACIP) Study Two-Year Follow-up

TLDR

Patients with ischemia detected on stress testing or ambulatory ECG monitoring are at higher risk of cardiac events, yet it is unclear whether more aggressive treatment improves their prognosis. A larger long‑term study is required to confirm the benefit of initial revascularization and to evaluate the potential of intensified drug therapy. The ACIP study randomized 558 patients with coronary anatomy amenable to revascularization to three strategies: angina‑guided drug therapy, angina plus ischemia‑guided drug therapy, or revascularization by angioplasty or bypass surgery. After two years, revascularization lowered mortality to 1.1% versus 6.6% and 4.4% for the drug‑therapy groups, reduced death or myocardial infarction to 4.7% versus 12.1% and 8.8%, and cut death, myocardial infarction or rehospitalization to 23.1% versus 41.8% and 38.5%, confirming that initial revascularization improves prognosis.

Abstract

Background Patients with ischemia during stress testing and ambulatory ECG monitoring have an increased risk of cardiac events, but it is not known whether their prognosis is improved by more aggressive treatment with anti-ischemic drugs or revascularization. Methods and Results The Asymptomatic Cardiac Ischemia Pilot study randomized 558 such patients who had coronary anatomy suitable for revascularization to three treatment strategies: angina-guided drug therapy (n=183), angina plus ischemia–guided drug therapy (n=183), or revascularization by angioplasty or bypass surgery (n=192). Two years after randomization, the total mortality was 6.6% in the angina-guided strategy, 4.4% in the ischemia-guided strategy, and 1.1% in the revascularization strategy ( P <.02). The rate of death or myocardial infarction was 12.1% in the angina-guided strategy, 8.8% in the ischemia-guided strategy, and 4.7% in the revascularization strategy ( P <.04). The rate of death, myocardial infarction, or recurrent cardiac hospitalization was 41.8% in the angina-guided strategy, 38.5% in the ischemia-guided strategy, and 23.1% in the revascularization strategy ( P <.001). Pairwise testing revealed significant differences between the revascularization and angina-guided strategies for each comparison. Conclusions A strategy of initial revascularization appears to improve the prognosis of this population compared with angina-guided medical therapy. A larger long-term study is needed to confirm this benefit and to adequately test the potential of more aggressive drug therapy.