Long-Term Echocardiographic Response to Cardiac Resynchronization Therapy in Initial Nonresponders

JACC Heart Fail. 2015 Dec;3(12):990-7. doi: 10.1016/j.jchf.2015.09.006. Epub 2015 Nov 11.

Abstract

Objectives: The aim of this study was to investigate the frequency and clinical implications of a delayed echocardiographic response to cardiac resynchronization therapy (CRT).

Background: Long-term prognosis for CRT patients is routinely based on the assessment of echocardiograms after 6 to 12 months of therapy. Some patients, however, may require a longer period of therapy before echocardiographic improvements are detectable.

Methods: This observational study included all patients with heart failure (HF) receiving a CRT device at a single center from 2003 to 2011. Eligible patients met current indications and had technically adequate echocardiograms from before implantation, approximately 1 year after implantation (mid-term), and ≥3 years after implantation (long-term). A positive echocardiographic response to CRT was defined as a reduction in left ventricular end-systolic volume ≥15%. All-cause mortality was compared for patients in 3 response groups: mid-term responders, long-term responders, and nonresponders.

Results: During this study, 294 patients met the study criteria. Of the 120 patients who were nonresponders after 1 year, 52 (43%) experienced a delayed positive response. Delayed, long-term responders had mortality and hospitalization rates similar to mid-term responders and significantly lower than nonresponders.

Conclusions: Among patients surviving at least 3 years after implantation of a CRT device and with echocardiographic follow-up, a significant portion of nonresponders after 1 year of CRT experience a delayed echocardiographic response after a longer period of time. Survival and hospitalization rates were similar for all echocardiographic responders, regardless of the time at which the response occurred.

Keywords: cardiac resynchronization therapy; echocardiography; heart failure; nonresponders.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cardiac Resynchronization Therapy / methods*
  • Cardiac Resynchronization Therapy / mortality
  • Cause of Death / trends
  • Echocardiography / methods*
  • Emergency Responders*
  • Female
  • Follow-Up Studies
  • Heart Failure / diagnostic imaging*
  • Heart Failure / physiopathology
  • Heart Failure / therapy
  • Humans
  • Male
  • Stroke Volume / physiology*
  • Survival Rate / trends
  • Time Factors
  • United States / epidemiology