Risk stratification in patients with frequent premature ventricular complexes in the absence of known heart disease

BACKGROUND Frequent premature ventricular complexes (PVCs) can be an indicator of structural heart disease. OBJECTIVE The purpose of this study was to determine the prevalence of scarring detected by delayed enhancement cardiac magnetic resonance (DE-CMR) imaging in patients with frequent PVCs without apparent structural heart disease and to determine the value of programmed ventricular stimulation (PVS) for risk stratification in patients with frequent PVCs and myocardial scarring. METHODS DE-CMR imaging was performed in patients without apparent heart disease who had frequent PVCs and were referred for ablation. In the presence of scarring, scar volume was measured and correlated with outcome variables. All patients underwent PVS and were monitored for the occurrence of ventricular arrhythmias. Logistic regression was used to compare imaging and procedural findings with long-term outcomes, with adjustment for postablation ejection fraction (EF). RESULTS The study consisted of 272 patients (135 men; mean age 52 +/- 15 years; EF 52% +/- 12%). DE-CMR scar was found in 67 patients (25%), and 7 (3%) were found to have inducible ventricular tachycardia (VT). The presence and amount of DE-CMR were related to the risk of long-term VT independent of EF (hazard ratio 18.8 [95% confidence interval] [2.0-176.6], P=.01; and hazard ratio 1.4 [1.1-1.7] per cm(3) scar, P=.001, respectively). The positive predictive value and negative predictive value of PVS for VT during long-term follow-up were 71% and 100%, respectively. CONCLUSION Preprocedural cardiac DE-CMR and PVS can be used to identify patients with frequent PVCs without apparent heart disease who are at risk for VT.