Population-based study of out-of-hospital sudden cardiovascular death: incidence and causes of death in middle-aged adults

Abstract

Introduction and objectives: The data of mortality of out-of-hospital sudden cardiovascular death in middle-aged adults have been poorly characterized. The aim of this study is to analyze their epidemiological, clinical and pathological characteristics.

Methods: Population observational study of all cardiovascular deaths in people 35-49 years old in Vizcaya between 2003 and 2008. The data of Mortality Register and Forensic Pathology Service were analyzed. The out-of-hospital sudden deaths subjected to forensic autopsy were identified.

Results: 216 of the 465 cardiovascular deaths were sudden deaths. The main cause was ischemic heart disease (N=140/216). Other conditions were: cardiomyopathies (N=32), cerebrovascular diseases (N=19) and sudden arrhythmic death in structurally normal hearts (N=10). The causes varied significantly in relation to gender and age. Ten percent had been diagnosed in life of a cardiovascular disease; 66% had cardiovascular risk factors and 27% had recently consumed ethanol and/or abuse drugs. The incidence of sudden death was 13.2/100,000 inhabitants/year, representing 46% of cardiovascular deaths. The incidence was 3.77 times higher in males than in females and increased with the age.

Conclusions: The incidence of sudden death in Vizcaya was lower than in other industrialized countries. In middle-aged adults out-of-hospital sudden cardiac death is the first manifestation of disease in half of all cardiovascular deaths. One challenge in prevention is the development of strategies to identify the highest risk people within the general population at low risk. Studies based on forensic autopsies improve our understanding of cardiovascular mortality.