Out of hospital sudden cardiac death in Italy: a population-based case-control study

Sudden cardiac death (SCD) is a major cause of death in western countries, with coronary heart disease (CHD) being the basis of over 70% of SCD. Incidence in high-CHD risk countries has already been studied, but this information is not available for Mediterranean low-CHD risk countries. Incidence is of paramount importance when cost-effectiveness rate of actions against SCD must be estimated.

We estimated the incidence of SCD and its potential risk associated with clinical variables, by a means of a case-control study in a general practice setting. The enrolled general practitioners (GPs) provided data about the total number of their patients, and identified all their patients who suffered an out-of-hospital SCD during the previous 365 days. Two age-matched and gender-matched controls visiting GPs office after the SCD selection were also selected. We used a structured questionnaire to obtain information about potential risk factors for SCD. Covariates that were univariately associated with SCD were included in the multivariate regression analyses.

In a population of 297 340 (age greater than 14 years), a total of 230 cases were identified (0.77 per 1000 individuals), mostly occurring at home and among persons with known high cardiovascular risk. In the multivariate analysis only CHD (OR: 1.67; 95% CI: 1.09-2.58), arrhythmia (OR: 2.2; 95% CI: 1.3-3.9), obesity (OR: 2.3; 95% CI: 1.5-3.6), alcohol abuse (OR: 1.8; 95% CI: 1.2-2.7), and family history of CHD (OR 3.1; 95% CI: 1.8-5.3) resulted in a significant association with SCD.

The incidence of SCD in Italy is lower than that reported in high-CHD risk population, most of the cases occurring at home and among persons with known high cardiovascular risk. Implementing recommendations for these patients seems to be the most effective strategy to reduce the incidence of SCD.