Objective: To evaluate the prevalence and prognostic significance of asymptomatic complex or frequent ventricular premature beats detected during ambulatory electrocardiographic (ECG) monitoring.
Design: Cohort study with a follow-up period of 4 to 6 years.
Participants: Surviving patients of the original Framingham Heart Study cohort and offspring of original cohort members (2727 men and 3306 women).
Measurements: One-hour ambulatory electrocardiography.
Results: The age-adjusted prevalence of complex or frequent arrhythmia (more than 30 ventricular premature complexes per hour or multiform premature complexes, ventricular couplets, ventricular tachycardia, or R-on-T ventricular premature complexes) was 12% (95% Cl, 11% to 13%) in the 2425 men without clinically evident coronary heart disease and 33% (Cl, 24% to 42%) in the 302 men with coronary heart disease. The corresponding values in women (3064 without disease and 242 with disease) were 12% (Cl, 11% to 13%) and 26% (Cl, 9% to 43%). After adjusting for age and traditional risk factors for coronary heart disease in a Cox proportional hazards model, men without coronary heart disease who had complex or frequent ventricular arrhythmias were at increased risk for both all-cause mortality (relative risk, 2.30; Cl, 1.65 to 3.20) and the occurrence of myocardial infarction or death from coronary heart disease (relative risk, 2.12; Cl, 1.33 to 3.38). In men with coronary heart disease and in women with and without coronary heart disease, complex or frequent arrhythmias were not associated with an increased risk for either outcome.
Conclusions: In men who do not have clinically apparent coronary heart disease, the incidental detection of ventricular arrhythmias is associated with a twofold increase in the risk for all-cause mortality and myocardial infarction or death due to coronary heart disease. The preventive and therapeutic implications of these findings await further investigation.