Chronic Chagas Cardiomyopathy Patients and Resynchronization Therapy: a Survival Analysis

Abstract Introduction: Chagas disease represents an important health problem with socioeconomic impacts in many Latin-American countries. It is estimated that 20% to 30% of the people infected by Trypanosoma cruzi will develop chronic Chagas cardiomyopathy (CCC), which is generally accompanied by heart failure (HF). Cardiac resynchronization therapy (CRT) may be indicated for patients with HF and electromechanical dysfunctions. Objective: The primary endpoint of this study was to analyze the response to CRT in patients with CCC, while the secondary endpoint was to estimate the survival rates of CRT responder patients. Methods: This is an observational, cross-sectional and retrospective study. The records of 50 patients with CRT pacing devices implanted between June 2009 and March 2017 were analyzed. For statistical analyses, Pearson's correlation was used along with Student's t-test, and survival was analyzed using the Kaplan-Meier method. A P value of <0.05 was considered significant. Results: Out of 50 patients, 56% were male, with a mean age of 63.4±13.3 years and an average CRT duration of 61.2±21.7 months. The mean QRS duration was 150.12±12.4 ms before and 116.04±2.2 ms after the therapy (P<0.001). The mean left ventricular ejection fractions (LVEF) were 29±7% and 39.1±12.2% before and after CRT, respectively (P<0.001). A total of 35 (70%) patients had a reduction of at least one New York Heart Association (NYHA) functional class after six months of therapy (P=0.014). The survival rate after 72 months was 45%. Conclusion: This study showed clinical improvement and a nonsignificant survival rate in patients with CCC after the use of CRT.

摘要 引言：查加斯病（Chagas disease）是众多拉丁美洲国家面临的重要公共卫生问题，同时伴随显著的社会经济影响。据估算，感染克氏锥虫（Trypanosoma cruzi）的人群中，有20%至30%会发展为慢性查加斯心肌病（CCC），此类患者通常伴随心力衰竭（HF）。对于合并机电功能异常的心力衰竭患者，心脏再同步化治疗（CRT）可作为其治疗指征。
研究目的：本研究的主要终点为分析慢性查加斯心肌病患者对心脏再同步化治疗的应答反应，次要终点为评估CRT应答患者的生存率。
研究方法：本研究为观察性、横断面回顾性研究。分析了2009年6月至2017年3月期间植入CRT起搏装置的50例患者的病历资料。统计学分析采用Pearson相关分析与Student t检验，生存率分析采用Kaplan-Meier法，以P值<0.05作为差异具有统计学意义的判定标准。
研究结果：50例患者中，男性占比56%，平均年龄为63.4±13.3岁，平均CRT治疗时长为61.2±21.7个月。治疗前平均QRS时限为150.12±12.4 ms，治疗后降至116.04±2.2 ms（P<0.001）。治疗前与治疗后的左心室射血分数（LVEF）分别为29±7%与39.1±12.2%（P<0.001）。共计35例（70%）患者在接受6个月治疗后，纽约心脏协会（NYHA）心功能分级至少降低1级（P=0.014）。患者72个月生存率为45%。
研究结论：本研究显示，慢性查加斯心肌病患者接受心脏再同步化治疗后可获得临床症状改善，但患者生存率未呈现统计学显著性差异。