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

Abstract Background Emerging evidence suggests that dynamic risk assessment may enhance sudden cardiac arrest (SCA) risk stratification. While cardiovascular events, including acute coronary syndrome (ACS) and heart failure (HF) hospitalization, are associated with increased SCA risk, the impact of recurrent events on subsequent SCA risk in a contemporary, real-world population is unknown. This study aimed to assess whether patients with a first-time ACS or HF hospitalization who experience a recurrent cardiovascular event have higher risk of SCA compared to those who do not. Methods The Observational Study of Cardiac Arrest Risk (OSCAR) is a prospective cohort study with adjudicated SCA outcomes. In the current study, patients who survived a first ACS or HF hospitalization were categorized into index ACS or HF cohorts. Participants were followed for recurrent cardiovascular events and SCA. Associations between recurrent events and SCA were assessed using Cox models with recurrent event modeled as a time-dependent variable. Findings were validated in the Framingham Heart Study (FHS). Results In the OSCAR discovery cohort, 2946 patients experienced an index ACS event. The incidence rate of SCA was higher following a recurrent ACS event than without (3.70 vs 1.28 per 100 patient-years). Recurrent ACS event was associated with a significantly higher risk of SCA (adjusted HR 3.15, 95% CI 2.06-4.83, p