Comparison of left ventricular lead upgrade vs continued medical care among patients eligible for cardiac resynchronization therapy at the time of defibrillator generator replacement: Predictors of left ventricular lead upgrade and associations with long-term outcomes

Heart Rhythm. 2020 Nov;17(11):1878-1886. doi: 10.1016/j.hrthm.2020.05.032. Epub 2020 Jun 1.

Abstract

Background: Randomized trials evaluating cardiac resynchronization therapy (CRT) have excluded patients with a pre-existing implantable cardioverter-defibrillator (ICD). The association of CRT upgrade with clinical outcomes in patients with a pre-existing ICD is unclear.

Objective: The purpose of this study was to examine a CRT-eligible population to evaluate clinical outcomes associated with CRT upgrade compared to patients who did not undergo CRT.

Methods: Using the National Cardiovascular Data Registry (NCDR) ICD Registry between April 2010 and December 2014, we created a hierarchical logistic regression model to identify predictors of CRT upgrade in a CRT-eligible ICD population. In the subpopulation of patients with Medicare-linked claims data, differential outcomes were determined with censoring at 3 years. The primary endpoint of this study was all-cause mortality, with secondary endpoints of rates of hospitalization and procedural complications.

Results: CRT upgrade was performed in 75.5% of CRT-eligible patients with pre-existing ICD (n = 15,803). Presence of left bundle branch block conduction was the strongest predictor of CRT upgrade (odds ratio [OR] 4.56; 95% confidence interval [CI] 4.08-5.11; P <.0001). In both unadjusted and adjusted analyses, CRT upgrade was associated with a reduction in mortality at 3 years (unadjusted hazard ratio [HR] 0.80; 95% CI 0.70-0.92; P = .001; adjusted HR 0.84; 95% CI 0.72-0.98; P = .02, respectively). Compared to patients with ICD generator replacement only, patients who underwent CRT upgrade experienced no different 3-year rates of hospitalization (adjusted HR 1.01; 95% CI 0.91-1.12; P = .81) or 1-year periprocedural complication rates (adjusted HR 1.07; 95% CI 0.79-1.45; P = .66).

Conclusion: In a national registry of CRT-eligible patients with pre-existing ICD, upgrade to CRT was associated with lower rates of mortality than continued medical management.

Keywords: Adverse events; Cardiac resynchronization therapy; Generator replacement; Implantable-cardioverter defibrillator; Mortality.

Publication types

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

MeSH terms

  • Aged
  • Cardiac Resynchronization Therapy / methods*
  • Defibrillators, Implantable*
  • Female
  • Follow-Up Studies
  • Heart Failure / physiopathology
  • Heart Failure / therapy*
  • Heart Ventricles / physiopathology*
  • Humans
  • Male
  • Registries*
  • Retrospective Studies
  • Treatment Outcome