Patients upgraded to cardiac resynchronization therapy due to pacing-induced cardiomyopathy are at low risk of life-threatening ventricular arrhythmias: a long-term cause-of-death analysis

Europace. 2018 Jan 1;20(1):89-96. doi: 10.1093/europace/euw321.

Abstract

Aims: Upgrade to cardiac resynchronization therapy (CRT) should be offered to patients who have developed pacing-induced cardiomyopathy with conventional right ventricular pacing. The extent to which these patients would also benefit from defibrillator back-up at the time of CRT upgrade is, however, unknown.

Methods and results: Retrospective observational cohort study of 199 patients with pacing-induced cardiomyopathy and no history of sustained ventricular arrhythmia, including 104 upgraded to CRT-Pacemaker (CRT-P) and 95 upgraded to CRT-Defibrillator (CRT-D). The incidence of ventricular arrhythmias and the risk of sudden arrhythmic death obtained through a cause-of-death analysis based on clinical data and necropsy results were assessed and compared between the two groups. During a mean follow-up of 66 ± 24 months, 40 (38.5%) CRT-P patients died: three from primary arrhythmic death, while the remaining died of different causes (especially progressive heart failure), giving an incidence of 6.2 sudden arrhythmic deaths per 1000 patient-years. No episode of sustained VT was observed in the study group. There were no sudden arrhythmic deaths in the CRT-D group during a shorter follow-up, but the small and non-significant difference in all-cause mortality between CRT-Pacemaker (CRT-P) and CRT-D groups was mostly accounted for by an increase in non-sudden death. Women upgraded to CRT were at particularly low risk of all-cause mortality compared with men (HR 0.232, P = 0.048).

Conclusion: Our findings suggest that patients who develop pacing-induced cardiomyopathy and are upgraded to CRT may not derive any significant benefit from the addition of the defibrillator in the absence of a history of ventricular arrhythmias.

Keywords: Cardiac resynchronization therapy; Cause of death; Implantable cardioverter-defibrillator; Pacemaker; Sudden arrhythmic death; Ventricular arrhythmias.

Publication types

  • Comparative Study
  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Arrhythmias, Cardiac / etiology
  • Arrhythmias, Cardiac / mortality
  • Arrhythmias, Cardiac / physiopathology
  • Arrhythmias, Cardiac / therapy*
  • Cardiac Pacing, Artificial / adverse effects*
  • Cardiac Pacing, Artificial / methods
  • Cardiac Pacing, Artificial / mortality
  • Cardiac Resynchronization Therapy Devices*
  • Cardiac Resynchronization Therapy* / adverse effects
  • Cardiac Resynchronization Therapy* / mortality
  • Cardiomyopathies / etiology
  • Cardiomyopathies / mortality
  • Cardiomyopathies / physiopathology
  • Cardiomyopathies / therapy*
  • Cause of Death
  • Death, Sudden, Cardiac / etiology
  • Death, Sudden, Cardiac / prevention & control*
  • Defibrillators, Implantable*
  • Disease-Free Survival
  • Electric Countershock / adverse effects
  • Electric Countershock / instrumentation*
  • Electric Countershock / mortality
  • Female
  • Humans
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Treatment Outcome