Risk Factors of Sudden Death From Subarachnoid Hemorrhage

Background and Purpose—One in every 4 subarachnoid hemorrhage (SAH) patients dies suddenly outside hospital, but most SAH risk factor studies focus on hospitalized patients. We studied the differences in risk factors between hospitalized SAH and sudden-death SAH patients. Methods—The population-based FINRISK study cohort of 65 521 individuals was followed up for 1.52 million person-years. The Cox proportional hazards model calculated hazard ratios (HRs), with all analyses adjusted for known SAH risk factors, marital status, and socioeconomic status. A competing risks model analyzed differences in risk factors between hospitalized SAHs and sudden-death SAHs. Results—We identified 98 sudden-death SAHs and 445 hospitalized SAHs confirmed by autopsy or by standard SAH diagnostics. Increase by 5 cigarettes smoked per day elevated sudden-death SAH risk (HR, 1.28; 95% confidence interval [CI], 1.17–1.39) more than hospitalized SAH risk (HR, 1.19; 95% CI, 1.13–1.24; P=0.05 for difference). Per SD (21.4 mm Hg) inc...