Impact of non-culprit coronary chronic total occlusion on outcomes after ST-elevation myocardial infarction complicated by out-of-hospital cardiac arrest

Abstract Background Out-of-hospital cardiac arrest (OHCA) in the setting of ST-segment elevation myocardial infarction (STEMI) remains associated with high mortality. Chronic total occlusions (CTOs) are frequent in coronary artery disease and have been linked to poor outcomes in acute coronary syndromes, but their prognostic impact in OHCA-STEMI patients is unclear. Methods We analyzed data from the prospective PROCAT registry including consecutive OHCA patients with return of spontaneous circulation and STEMI who underwent emergent coronary angiography between 2007 and 2024. The presence of CTO was assessed at baseline. The primary endpoint was 90-day all-cause mortality; secondary endpoints included in-hospital mortality. Logistic regression and Cox models were used to assess associations between CTO and outcomes. Results Among 352 patients included, CTO was present in 58 (16%). CTO patients were older, had more comorbidities, and exhibited more extensive coronary artery disease. In-hospital mortality (55.2% vs. 39.8%, p = 0.030) and 90-day mortality (69.0% vs. 49.0%, p = 0.005) were higher in the CTO group. In univariable analysis, CTO was associated with increased in-hospital death (OR 1.86, 95% CI 1.05–3.29) and 90-day mortality (HR 1.76, 95% CI 1.18–2.62). However, after multivariable adjustment for clinical and resuscitation-related factors, CTO was not independently associated with either endpoint. Conclusions In OHCA-STEMI patients, CTO is associated with increased crude mortality but does not independently predict outcomes after adjustment. CTO likely reflects a higher atherosclerotic burden rather than being a direct driver of early mortality. Its detection remains clinically relevant for long-term management and secondary prevention.