CTO PCI vs. medical therapy in stable CAD: real-world outcomes from a target trial emulation of SCAAR registry data

BACKGROUND: The prognostic benefit of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) in stable coronary artery disease (CAD) remains uncertain. OBJECTIVES: To evaluate long-term survival following CTO PCI compared with medical therapy (MT) using target trial emulation and a nationwide real-world registry. METHODS: We included 7813 patients with stable CAD and a documented CTO from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) between 2015 and 2024. CTO PCI was modeled as a time-dependent exposure. The primary outcome was all-cause mortality. We used inverse probability of treatment weighting (IPTW), time-dependent Cox regression, and instrumental variable (IV) analysis to adjust for confounding. RESULTS: Over a median follow-up of 5.08 years, 1253 deaths occurred. While unadjusted survival favored CTO PCI (HR 0.74; 95% CI, 0.64-0.86; p < 0.001), IPTW and IV adjustment showed no significant reduction in mortality compared with MT (IPTW HR 0.94; 95% CI, 0.80-1.10; p = 0.41; IV HR 1.00; 95% CI, 0.71-1.40; p = 0.999). Successful CTO PCI was associated with improved survival (HR 0.74; 95% CI, 0.62-0.87), whereas unsuccessful procedures were not (HR 1.08; 95% CI, 0.79-1.47). Subgroup analyses showed no consistent benefit, although a modest survival advantage was observed in non-diabetic patients. CONCLUSIONS: In this large nationwide study using target trial emulation, CTO PCI was not associated with improved overall survival compared with MT. Only successful procedures conferred a benefit, highlighting the importance of procedural success and patient selection in CTO revascularization strategies.