title: Time to left ventricular reverse remodeling after cardiac resynchronization therapy: Better late than never.
abstract: BACKGROUND
  Left ventricular reverse remodeling (LVRR), defined as reduction of end-diastolic and end-systolic dimensions and improvement of ejection fraction, is associated with the prognostic implications of cardiac resynchronization therapy (CRT). The time course of LVRR remains poorly characterized. Nevertheless, it has been suggested that it occurs ≤6 months after CRT.
  
  
  OBJECTIVE
  To characterize the long-term echocardiographic and clinical evolution of patients with LVRR occurring >6 months after CRT and to identify predictors of a delayed LVRR response.
  
  
  METHODS
  A total of 127 consecutive patients after successful CRT implantation were divided into three groups according to LVRR response: Group A, 19 patients (15%) with LVRR after >6 months (late LVRR); Group B, 58 patients (46%) with LVRR before 6 months (early LVRR); and Group C, 50 patients (39%) without LVRR during follow-up (no LVRR).
  
  
  RESULTS
  The late LVRR group was older, more often had ischemic etiology and fewer patients were in NYHA class ≤II. Overall, group A presented LVRR between group B and C. This was also the case with the percentage of clinical response (68.4% vs. 94.8% vs. 38.3%, respectively, p<0.001), and hospital readmissions due to decompensated heart failure (31.6% vs. 12.1% vs. 57.1%, respectively, p<0.001). Ischemic etiology (OR 0.044; p=0.013) and NYHA functional class <III (OR 0.056; p=0.063) were the variables with the highest predictive value for late LVRR.
  
  
  CONCLUSIONS
  Late LVRR has better clinical and echocardiographic outcomes than no LVRR, although with a suboptimal response compared to the early LVRR population. Ischemic etiology and NYHA functional class <III are predictors of late LVRR.
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal. Electronic address: andreviveirosmonteiro@gmail.com.
authors.forename: André
authors.initials: A
authors.lastname: Viveiros Monteiro
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Martins Oliveira
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Silva Cunha
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Nogueira da Silva
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Feliciano
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Luísa
authors.initials: L
authors.lastname: Branco
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Rio
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pimenta
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Ana Sofia
authors.initials: AS
authors.lastname: Delgado
authors.affiliation: Serviço de Cardiologia do Hospital de Santa Marta - Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Cruz Ferreira
mesh_terms: D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D006333:Heart Failure; D006801:Humans; D017202:Myocardial Ischemia / Q000209:etiology; D011379:Prognosis; D020257:Ventricular Remodeling
keywords: Cardiac resynchronization therapy; Evolução temporal; Left ventricular reverse remodeling; Remodelagem inversa do ventrículo esquerdo; Terapêutica de ressincronização cardíaca; Time course