Meta-analysis of ventricular premature complexes and their relation to cardiac mortality in general populations.

Although previous studies have shown that frequent ventricular premature complexes (VPCs) in patients with established heart disease are associated with increased risk of cardiac mortality, the significance of VPCs in general populations is unclear. The aim of this study was to assess the association between VPCs and risk of sudden cardiac death or total cardiac death in general populations by conducting a meta-analysis of published research. The electronic databases MEDLINE and Embase were searched for relevant studies. Data were abstracted using standardized forms. Study-specific relative risk estimates were pooled using a random-effects meta-analysis model. Eleven studies comprising a total of 106,195 participants sampled from general populations were included. Studies generally defined frequent VPCs as occurring ≥1 time during a standard electrocardiographic recording or ≥30 times over a 1-hour recording. The prevalence of frequent VPCs in the studies ranged from 1.2% to 10.7%. The overall adjusted relative risk for sudden cardiac death comparing participants with frequent VPCs versus those without frequent VPCs was 2.64 (95% confidence interval 1.93 to 3.63). The corresponding value for total cardiac death was 2.07 (95% confidence interval 1.71 to 2.50). Although most studies made attempts to exclude high-risk subjects, such as those with histories of cardiovascular disease, they did not test participants for underlying structural heart disease. In conclusion, findings from observational studies in general populations indicate that frequent VPCs are associated with a substantial increase in the risk for sudden cardiac death and total cardiac death. Further study is needed to determine the role of confounding and underlying structural heart disease in the observed association and its utility in cardiovascular risk prediction.