Predictors of Left Ventricular Ejection Fraction Improvement after Radiofrequency Catheter Ablation in Patients with PVC-Induced Cardiomyopathy: A Systematic Review

BACKGROUND: Frequent premature ventricular contractions (PVC) can result in PVCinduced cardiomyopathy (PVC-iCMP), leading to reduced Left Ventricular Ejection Fraction (LVEF) that can be improved by radiofrequency catheter ablation (RFCA). We performed a systematic review to determine the variables predicting LVEF improvement after RFCA in PVCiCMP. METHODS: We developed a "population, intervention, outcome and predictive factors" framework and searched MEDLINE, Embase, Cochrane Library, Cochrane Collaboration and Cochrane Database of Systematic Reviews (CDSR) for full-text, peer-reviewed publications. These publications addressing predictive factors of LVEF improvement showed ≥5% improvement only if deemed significant by the respective study, ≥10% or ≥ 50% after RFCA ablation in patients with PVCiCMP with no type/date/language limitation until the end of 2017. RESULTS: Our initial search yielded 2226 titles, 1519 of which remained after removing the duplicates. Finally, 11 articles - 2 cohorts, 7 quasi-experimental studies, 1 case-control and 1 metaanalysis- were included. Sustained successful ablation, higher baseline PVC burden, LVEF, QRS duration, post-PVC systolic blood pressure rise and post-PVC pulse pressure change, the absence of an underlying cardiomyopathy, younger age, and variability of the frequency of PVCs during the day and lower left ventricular end-diastolic diameter (LVEDD) have been suggested as predictive factors for LVEF improvement in patients with PVC-iCMP. CONCLUSION: The mentioned factors may all be useful to identify PVC-iCMP patients who would benefit from RFCA, although the evidence is not yet strong enough.