Risk stratifiers for sudden cardiac death (SCD) in the community: primary prevention of SCD

CHD was associated with a 2.8-5.3-fold increase in the risk of SCD and CHF was associated with a 2.6-6.2-fold increased risk Left ventricular dysfunction, in par-There are currently 250,000 sudden cardiac deaths ticular, is the most powerful independent predictor of SCD (SCD) in the United States every year constituting approxin patients with both ischemic and non-ischemic carimately 50% of all coronary heart disease (CHD) deaths diomyopathy However, the majority of SCDs occur in Despite the decline in CHD mortality over the last those without known cardiac disease and not in the welldecade, little proportionate change has been seen in the recognized high-risk subsets such as patients with a history characteristics of CHD deaths. The majority of deaths are of MI, severe LV dysfunction, or a prior cardiac arrest [10]. still sudden, occurring out-of-hospital and in the Approximately 55% of male and 63% of female SCD emergency room SCD is the most common cause of victims have no previous history of heart disease, and ischemic heart disease death in adults under the age of 65 therefore SCD is often the initial manifestation of heart years [2,3] and, therefore, is a major public health problem disease Therefore, SCD in this segment of the in the US and other industrialized countries Despite population must be addressed to impact significantly on the improved cardiopulmonary resuscitation, survival to hospioverall incidence of SCD. tal discharge is only 3-6% in unselected cases in major Despite the large numbers of SCDs in the general metropolitan centers. Even in cities with advanced EMS population, the overall incidence is only 0.1% per year systems, such as in Seattle, USA, survival to hospital Therefore, to reduce the incidence of SCD, These percentages do not include those arrests that we must either accurately identify those at risk or develop are not witnessed and for which resuscitation is not safe, low-cost interventions that can be applied to the attempted. Undoubtedly, this percentage will improve with population at large. There are a number of populationan increase in deployment of automated external defibrilbased characteristics that appear to predict risk of SCD in lators and public access defibrillation, however, it is clear the general population. These include traditional CHD risk from these statistics that any substantial reduction in SCD factors, lifestyle and dietary habits, genetic influences, incidence will require effective preventive interventions.