Risk factors for sudden cardiac death in middle-aged British men

Background Risk factors specific to sudden cardiac death (SCD), ie, death within 1 hour after onset of symptoms, have been poorly identified, although recent findings from the present study incriminate heavy drinking and elevated heart rate. This paper examines the relations between a wide range of established and potential risk factors for ischemic heart disease (IHD) and SCD to identify independent risk factors for SCD and factors that might particularly or specifically relate to SCD. Methods and Results We present a prospective study of a cohort that was drawn from general practices in 24 British towns of 7735 middle-aged men who were followed up for 8 years. During 8 years of follow-up, the men experienced 488 major IHD events (nonfatal and fatal), of which 117 (24%) were classified as SCD. Age, preexisting IHD, arrhythmia, systolic blood pressure, blood cholesterol, elevated heart rate (≥90 beats per minute), physical activity (all, P P =.06), HDL cholesterol ( P P Conclusions Three risk factors appear to be specific or particular to the risk of SCD, and these and other risk factors operate differently in patients with versus those without preexisting IHD. These findings have implications for the causes and prevention of SCD.