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

Abstract

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.

Keywords: Long-term outcomes; Mortality; Out of hospital cardiac arrest survivors; readmission.