Pacinchagas: risk stratification in pacemaker patients with Chagas' heart disease

Abstract

Chagas disease (ChD) is considered a major public health problem in Latin America and recent estimates suggest about 10 million people infected worldwide. Progression to chronic chagasic cardiomyopathy (CCC) occurs in approximately 20-40% of those infected, and the main causes of death are heart failure (HF) and sudden death (SD). The conduction system is commonly affected and CCC remains one of the most frequent indications for pacemaker implantation in Brazil. Several variables have already been evaluated in order to stratify the risk of patients with CCC, however, patients with pacemaker were excluded from the main studies of this issue. Objectives: 1. To define clinical and functional predictors of death and/or cardiovascular events in patients with CCC and pacemaker. 2. To assess the weight of clinical and functional variables that determine the outcome during the follow-up (risk score). 3. To assess the impact of applying the risk score at the time of exchange the generator. Outcome variables: * Primary: total mortality, arrhythmic mortality, worsening heart failure, sustained ventricular tachycardia. * Secondary: syncope, thromboembolism, hospitalization rates, electronic programming. Methods: This study will be held in two distinct phases. The first phase, retrospective, a relational database with clinical and functional variables of patients with pacemaker and CCC enrolled in the Clinical Unit of Cardiac Pacing of the Heart Institute, University of São Paulo, will be performed. After univariate and multivariate analysis, the cohort will be used for development and validation of a prognostic risk score for this specific population. The second phase, prospective, consist in applying the risk score obtained in Phase I to patients with CCC and pacemaker at the moment of generator's replacement. Patients classified as intermediate/high cardiovascular risk will be selected and randomized to ICD implantation or not. Patients will be systematically evaluated for cardiac resynchronization therapy (CRT). Patients presenting CF e II and LVEF d 35% an upgrade for CRT will be automatically performed and then randomized to defibrillator (ICD) implantation. (AU)