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Cardiac resynchronization is pro-arrhythmic in the absence of reverse ventricular remodelling: a systematic review

Bishoy Deif1, Brennan Ballantyne1, Fahad Almehmadi1

  • 1Division of Cardiology, Department of Medicine, Western University, 339 Windermere Road, London, Ontario, Canada.

Cardiovascular Research
|July 17, 2018
PubMed

Insights

Cardiac resynchronization therapy (CRT) responders show reduced ventricular arrhythmias (VAs) compared to non-responders. CRT non-responders may have an increased risk of VAs, suggesting a potential pro-arrhythmic effect without reverse remodeling.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Heart Failure Management

Background:

  • Cardiac resynchronization therapy (CRT) reduces mortality and heart failure hospitalizations.
  • The impact of CRT on ventricular arrhythmias (VAs) is debated, with some evidence suggesting a neutral effect.
  • A hypothesis exists that CRT with left ventricular (LV) epicardial stimulation may be pro-arrhythmic in non-responders but anti-arrhythmic in responders.

Purpose of the Study:

  • To systematically review and meta-analyze the rate of VAs in patients undergoing CRT.
  • To compare VA rates between CRT-defibrillator (CRT-D) non-responders, CRT-D responders, and patients with implantable cardioverter-defibrillator (ICD) only.
  • To investigate the potential pro-arrhythmic or anti-arrhythmic effects of CRT based on patient response.

Main Methods:

  • Systematic review and meta-analysis of retrospective cohort, prospective cohort, and randomized controlled trials.
  • Studies compared VA rates between CRT-D non-responders, CRT-D responders, and ICD-only patients.
  • CRT-D responders were defined by discrete LV volumetric values assessed by imaging.

Main Results:

  • 23 full-text articles were analyzed from 2579 initial citations.
  • CRT-D responders had significantly lower VA rates than CRT-D non-responders (RR 0.49) and ICD-only patients (RR 0.59).
  • CRT-D mechanical non-responders had a higher likelihood of VAs compared to ICD-only patients (RR 0.76).

Conclusions:

  • CRT-D non-responders exhibit higher VA rates than CRT-D responders and ICD-only patients.
  • These findings suggest that CRT with LV epicardial stimulation might be pro-arrhythmic in the absence of reverse ventricular remodeling.
  • CRT appears to confer an anti-arrhythmic benefit in mechanical responders.
Abstract

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