Long-term clinical outcomes and predictors for survivors of out-of-hospital cardiac arrest

Aims Improvement in resuscitation efforts has translated to an increasing number of survivors after out-of-hospital cardiac arrest (OHCA). Our objectives were to assess the long-term outcomes and predictors of mortality for patients who survived OHCA. Methods We conducted a population-based cohort study linking the Toronto RescuNET cardiac arrest database with administrative databases in Ontario, Canada. We included patients with non-traumatic OHCA from December 1, 2005 to December 31, 2014. The primary outcomes were mortality at 1 year and 3 years. Cox proportional hazard models were constructed to evaluate the predictors of mortality. Results Among the 28,611 OHCA patients who received treatment at the scene of arrest, 1591 patients survived to hospital discharge. During hospitalization, 36% received coronary revascularizations and 27% received an implantable cardioverter defibrillator. At one year after discharge, 12.6% of patients had died and 37.3% were readmitted. At 3 years, mortality rate was 20% and all-cause readmission rate was 54.1%. Older age and a history of cancer were associated with higher risk of 3-year mortality. Shockable rhythm at presentation (hazard ratio [HR] 0.62, 95% CI 0.45–0.85), use of coronary revascularization (HR 0.37, 95% CI 0.28–0.51) or implantable cardioverter defibrillator (HR 0.28, 95% CI 0.20–0.41) was associated with substantially lower 3-year mortality. Prior cardiac conditions and other arrest characteristics were not associated with long-term mortality. Conclusions Survivors of OHCA face significant morbidity and mortality after hospital discharge. Clinical trials are needed to evaluate the potential benefits of invasive cardiac procedures in OHCA survivors.