Upgrade is independently associated with short-term mortality after cardiac resynchronization therapy.   

Abstract

Background: Cardiac resynchronization therapy (CRT) improves outcomes in heart failure (HF) patients with left bundle branch block (LBBB). However, the benefits of CRT in patients with previous pacing are still uncertain. The aim is to compare the short-term mortality between upgrade and De novo-CRT implantation.Methods: Prospective cohort study that included HF patients indicated for CRT with left ventricular ejection fraction (LVEF) of less than 35%. Data were collected to investigate mortality predictors after 1 year. The overall survival was calculated by the Kaplan-Meier method and multivariate analysis using Cox's regression model was performed. A value of p<0.05 was considered as significant.Results: 93 patients were evaluated with a mean follow-up of 1.0±0.6year. Of these, 22 (23.7%) were upgraded from right ventricular pacing. Chagas Disease (CD) was the most prevalent cause of HF with 29 (31.2%) individuals. LVEF at 6 months increased after CRT: 24,0%±7.8 to 30.3%±11.5, p=0.007, and there was no difference between upgraded patients and De novo CRT, p=0.26. Overall mortality at 1-year was 30.1% (28 patients). In univariate analysis, CD and upgraded therapy were associated with high mortality,