Dynamic Risk Trajectories for Sudden Cardiac Arrest: The Role of Recurrent Cardiovascular Events

Although cardiovascular events increase sudden cardiac arrest (SCA) risk, the impact of recurrent events on subsequent SCA risk in a contemporary population is unknown. This study assessed whether patients with a first-time acute coronary syndrome (ACS) or heart failure (HF) hospitalization who experience a recurrent cardiovascular event have increased SCA risk.

The OSCAR (Observational Study of Cardiac Arrest Risk) is a prospective cohort with adjudicated SCA outcomes. The current study followed up patients who survived a first ACS or HF hospitalization (the index ACS or HF cohorts) for recurrent cardiovascular events and SCA. Recurrent event was a time-dependent variable in Cox models predicting SCA. Findings were validated in the FHS (Framingham Heart Study).

Among 2946 patients in the index ACS cohort, incidence of SCA was higher following a recurrent ACS event than without (3.70 versus 1.28 per 100 patient-years). A recurrent ACS event was associated with higher risk of SCA (adjusted hazard ratio [HR], 3.15 [95% CI, 2.06-4.83]; P<0.0001). Among 6711 patients in the index HF cohort, incidence of SCA was higher following a recurrent HF event than without (1.35 versus 0.97 per 100 patient-years), and SCA risk was higher with recurrent HF (HR, 1.79 [95% CI, 1.44-2.23]; P<0.0001). In the FHS cohort, risk of SCA was higher with recurrent ACS (HR, 2.85 [95% CI, 1.66-4.90]; P=0.0002); the association was not significant for recurrent HF (HR, 1.49 [95% CI, 0.73-3.03]; P=0.27).

Recurrent events were associated with higher risk of SCA; dynamic clinical trajectories of recurrent cardiovascular events may inform prevention of SCA.