Abstract
BACKGROUND: The effect of chronic total occlusion (CTO) revascularization on survival remains controversial. Furthermore, data regarding outcome differences for CTO revascularization based on left ventricular systolic function (LVSF) are limited. The differential outcomes from CTO revascularization in patients with preserved LVSF (PLVSF) versus reduced LVSF (RLVSF) were assessed. METHODS: A total of 2,173 CTO patients were divided into either a PLVSF (n = 1661, Ejection fraction ≥ 50%) or RLVSF (n = 512, < 50%) group. Clinical outcomes were compared between successful CTO revascularization (SCR) versus optimal medical therapy (OMT) within each group. The primary endpoint was a composite of all-cause death or non-fatal myocardial infarction. Inverse probability of treatment weighting for endpoint analysis and a contrast test for comparison of survival probability differences according to LVSF were used. RESULTS: Patients with RLVSF had a mean 37% ejection fraction (EF) and 19% had EF < 30%. The median follow-up duration was 1,138 days. Regardless of LVSF, the primary endpoint incidence was significantly lower in patients treated with SCR [RLVSF: 29.7% vs. 49.7%, hazard ratio (HR) = 0.46, 95% confidence interval (CI): 0.36-0.62, p < 0.0001; PLVSF 7.3% vs. 16.9%, HR = 0.68, 95% CI: 0.54-0.93, p = 0.0019], which was mainly driven by a reduction in cardiac death. The difference in survival probability was greater and became more pronounced over time in patients with RLVSF than with PLVSF (1-year, p = 0.197; 3-years, p = 0.048; 5-years, p = 0.036). CONCLUSIONS: SCR was associated with better survival benefit than OMT regardless of LVSF. The benefit was greater and became more significant over time in patients with RLVSF versus PLVSF.