Aims: To examine risk factors for out-of-hospital cardiac arrest in the Reykjavik Study, a long-term, prospective, population-based cohort study that started in 1967.
Methods and results: From 1987 to 1996, 137 men and 44 women out of the 8006 men and 9435 women in the study sustained out-of-hospital cardiac arrest due to cardiac causes. Determinants included coronary artery disease (CAD), its classical risk factors, and age, body mass index (BMI), heart rate, cardiomegaly, and erythrocyte sedimentation rate. Electrocardiograms (ECGs) were examined for various abnormalities. Significance was determined by Cox regression analysis. In multivariable analysis, the risk in men was significantly associated with age, diastolic blood pressure, cholesterol, current smoking, and previous diagnosis of myocardial infarction (MI). In women, the risk was associated with diastolic blood pressure, elevated levels of cholesterol and triglycerides, and increased voltage on ECG. Increased BMI was inversely related to women's risk of out-of-hospital cardiac arrest.
Conclusion: In this prospective, population-based cohort study previous MI and the classical risk factors for CAD significantly increased the risk of out-of-hospital cardiac arrest, the endpoint of this study. Increased voltage on ECG additionally increased women's risk.