title: Prognostic significance of exercise-induced premature ventricular complexes: a systematic review and meta-analysis of observational studies.
abstract: BACKGROUND
  Exercise-induced premature ventricular complexes (EI-PVCs) are common during exercise stress tests. Their optimal management and prognostic significance remain uncertain.
  
  
  OBJECTIVE
  To perform meta-analysis of observational studies on the prognostic significance of EI-PVCs.
  
  
  METHODS
  A search was conducted on Medline and Embase. Inclusion criteria were observational studies comparing the prognosis of patients with and without EI-PVCs whilst exclusion criteria were studies without confounder adjustment and studies with zero endpoints. Composite endpoints included all-cause mortality, cardiac mortality and cardiovascular events. Relative risk of endpoints were analysed with random effects model. Meta-regression and sensitivity analysis were performed.
  
  
  RESULTS
  Ten studies were included. In asymptomatic patients who had no clinical evidence of heart disease, EI-PVCs were associated with a pooled risk ratio of 1.82 (95% CI 1.44 to 2.30) of developing adverse cardiovascular events over 16 years. The corresponding pooled RR for patients with symptomatic heart disease was 1.36 (95% CI 1.18 to 1.57) over 5.4 years. Sensitivity analysis: only EI-PVCs on the recovery phase of an exercise test, not during exercise, had adverse prognostic significance.
  
  
  CONCLUSIONS
  EI-PVCs are correlated with a higher risk of all cause death or cardiovascular events in the long term. This risk is elevated in asymptomatic patients without clinical heart disease and in patients with symptomatic heart disease. The fact that only EI-PVCs during recovery, and not during exercise, have poor prognostic value suggests that autonomic dysfunction may play a role in this association. Further studies are needed to see if autonomic manipulation by drugs or catheter-based methods can improve the poor prognosis associated with EI-PVCs.
authors.affiliation: Princess Margaret Hospital , Kowloon , Hong Kong.
authors.forename: Victor
authors.initials: V
authors.lastname: Lee
authors.affiliation: St Bartholomew's Medical School , London , UK.
authors.forename: Dhanuka
authors.initials: D
authors.lastname: Perera
authors.affiliation: University College London , London , UK.
authors.forename: Pier
authors.initials: P
authors.lastname: Lambiase
keywords: ARRHYTHMIAS