Assessing the Futility of Thrombolysis in Out-of-Hospital Cardiac Arrest. A Retrospective Cohort study.

Abstract Background Thrombolysis has been considered a potential intervention to improve outcomes in out-of-hospital cardiac arrest (OHCA). This retrospective cohort study aimed to evaluate whether thrombolysis offers any meaningful survival benefit by assessing 30-day survival and return of spontaneous circulation (ROSC) upon hospital arrival, with a focus on demonstrating futility.Methods Data from a single-centre registry, comprising 2,862 OHCA patients, including 171 who received thrombolysis, were analysed. Logistic regression was employed to calculate unadjusted and adjusted odds ratios (OR) with 95% confidence intervals (CI) for the primary outcome of 30-day survival and the secondary outcome of ROSC.Results The 30-day survival rate in the thrombolysis group was 4%, substantially lower than in the non-thrombolysis group. The unadjusted odds ratio (OR) for survival with thrombolysis was 0.36 (95% CI 0.16–0.81), and after adjusting for confounders, the OR decreased to 0.08 (95% CI 0.04–0.19), indicating a significantly reduced likelihood of survival with thrombolysis. The adjusted OR for achieving return of spontaneous circulation (ROSC) was 0.21 (95% CI 0.14–0.33), suggesting a similarly diminished likelihood of ROSC with thrombolysis. Both models were highly significant for predictors such as shockable rhythm (OR 15.89 for survival, OR 4.14 for ROSC), witnessed bystander CPR (OR 1.99 for survival, OR 2.04 for ROSC). A MacFaddens R-squared value of 0.27 for the primary outcome, represents a moderate model fit at best.Conclusion Thrombolysis administration in OHCA was associated with a significant reduction in both 30-day survival and ROSC rates, demonstrating the futility of thrombolysis in improving outcomes in this context. The poor fit of the regression models underscores the need for further investigation to identify additional factors that may impact survival, and to reevaluate the use of thrombolysis in OHCA management.