Abstract
BACKGROUND: Randomized trials of chronic total occlusion (CTO) revascularization vs medical therapy have yielded inconsistent results. OBJECTIVES: The aim of this study was to evaluate outcomes with an initial invasive strategy (INV) vs an initial conservative strategy (CON) in patients with coronary computed tomographic angiography (CCTA)-determined CTO in the ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) trial. METHODS: Participants in ISCHEMIA who underwent CCTA evaluated for CTO by the core laboratory (3,113 of 5,179 randomized patients [60%]) were categorized into subgroups with (100% stenosis) and without (<100% stenosis) CTO. Primary analysis compared outcomes in those randomized to INV vs CON using an intention-to-treat approach. Secondary analyses compared outcomes using inverse probability weighting to model successful CTO revascularization (REV) in all INV participants vs CON participants. RESULTS: Of the 3,113 CCTA-evaluable participants, 1,470 had at least 1 CTO (752 INV and 718 CON). INV did not reduce cardiovascular (CV) death or myocardial infarction (MI) (5-year difference -3.5%; 95% CI: -7.8% to 0.8%) and resulted in more procedural MIs (2.5%; 95% CI: 1.0%-4.0%) but fewer spontaneous MIs (-6.3%; 95% CI: -9.7% to -3.2%) than CON. CTO REV modeled across INV had a high probability (>90%) of any lower CV death or MI, MI, spontaneous MI, unstable angina, and heart failure counterbalanced by a higher rate of procedural MI. CTO REV significantly improved angina-related quality of life (mean difference 4.6 points), Rose Dyspnea Scale score (rescaled) (mean difference 5.3 points), and EQ-5D visual analog scale score (4.6 points). CONCLUSIONS: In the ISCHEMIA trial, the risks and benefits of INV compared with CON were similar among patients with and without CCTA-determined CTO (more frequent procedural MI, less frequent spontaneous MI, and significantly improved angina and dyspnea-related quality of life). In an observational comparison, successful CTO REV was associated with a high probability of lower CV death or MI (driven by lower MI) compared with CON. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).