Survival benefit of coronary revascularization after myocardial perfusion SPECT: The role of ischemia

Abstract

BackgroundSurvival benefit of revascularization over medical therapy (MT) in patients with stable ischemic heart disease (SIHD) is uncertain. We evaluated the prognostic effects of revascularization in patients with SIHD undergoing single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). MethodsOf 47,894 patients, 7973 had ischemia ≥ 5% of the left ventricle. Of these, 1837 underwent early revascularization (≤ 60 days after SPECT-MPI). The rest were MT subgroup. Follow-up period was 4.04 ± 1.86 years. Statin therapy intensity and adherence were assessed. Outcomes were all-cause mortality, death + non-fatal myocardial infarction (MI), and MACE [major adverse cardiac event = death + MI + late revascularization (> 60 days after SPECT-MPI)]. ResultsAmong patients with moderate-severe ischemia (≥ 10%), death rate was lower in early revascularization compared to MT subgroup (1.42%/year vs 3.12%/year, adjusted hazard ratio (HR) 0.67 (95% CI 0.50-0.90, P = .008). Death + MI and MACE rates were also lower, adjusted HR 0.69 (0.55-0.88, P = .003) and 0.80 (0.69-0.92, P = .003). Revascularization was beneficial in optimal statin therapy subgroup (death rate 1.04%/year vs 2.36%/year, adjusted HR 0.51 (0.30-0.86, P = .012). In mild ischemia (5%-9%), revascularization did not improve survival or MI-free survival, and was associated with higher MACE rate (8.86%/year vs 7.67%/year, adjusted HR 1.30 (1.12-1.52, P < .001). ConclusionCompared to MT, revascularization was associated with reduced risk of death, death + MI, and MACE in patients with moderate-severe ischemia, incremental over optimal statin therapy. In mild ischemia, revascularization was associated with higher risk of MACE, driven by late revascularization, with no impact on death and death + MI.