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

Chagas cardiomyopathy is the most prevalent non-ischemic cardiomyopathy in Latin America, with high morbidity and mortality even today. Treatment of these patients is based on the use of medications for heart failure. This study evaluated a cohort of patients with Chagas heart disease who used sacubitril valsartan at a referral hospital for the disease in Brazil. After six months, there was a symptomatic improvement in these individuals assessed by the NYHA classification, with a 44.3% reduction in the absolute number of patients classified as III-IV in the period (p 0.035), but without changes in the parameters on the echocardiogram for reverse ventricular remodeling and still high mortality rate and hospitalization. These results emphasize the importance of studying the use of sacubitril valsartan in chagas heart disease to better describe its effectiveness taking into account the peculiarities of these individuals.

Introduction: 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 uncertain, specially in a population witch Chagas disease is a prevalent cause of HF. Methods and Results: Prospective cohort study that included HF patients indicated for CRT with left ventricular ejection fraction (LVEF) of less than 35%. Clinical and demographic 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. Between May 2017 and September 2019, 93 patients were evaluated with a mean follow-up of 1,0 (0.6) year. Of these, 22 (23,7%) were upgraded from right ventricular pacing. Chagas Disease was the most prevalent cause of HF 29 (31,2%). In overall patients, LVEF at 6 months increased after CRT: 24,0% (7,8) to 30,3% (11,5), p=0.007, and there was no significant difference between upgraded patients and de Novo CRT, p=0.26. Overall mortality at 1-year was 28 (30,1%). In the univariate analysis, Chagas disease and upgraded therapy were associated with mortality at follow-up, HR: 3.9, CI: 1.8-8,4, p = 0.001 and HR: 4.7, CI: 2.2-9.9, p < 0.001, respectively. In the multivariate model, only upgraded therapy remained independently associated with the outcome, adjusted HR: 2.9, CI: 1.2-7,2, p = 0.02. Conclusion: In this specific HF population, with a high prevalence of Chagas disease cardiomyopathy, upgraded therapy was independently associated with worsened 1-year survival after CRT.