Relationship of reverse anatomical remodeling and ventricular arrhythmias after cardiac resynchronization

Cardiac resynchronization (CRT) affects reverse anatomical remodeling in patients with heart failure. CRT has also been associated with fewer ventricular arrhythmias and reduced sudden death in some clinical trials, but the predictors and mechanism of the antiarrhythmic actions of CRT have not been well defined. The purpose of this study is to investigate the relationship of reverse anatomical remodeling to ventricular arrhythmias in CRT patients.

A retrospective analysis was performed of the InSync III Marquis study, a prospective, randomized, multicenter CRT trial. Echocardiographic data from 198 patients were obtained at baseline and after 6 months of CRT, and anatomical responders were defined as a reduction in left ventricular end systolic volume (LVESV) of >or=15%. Anatomical responders (n = 71, 36%) demonstrated 29% fewer single premature ventricular contractions beats (PVCs) (P = 0.0001), 48% fewer PVC runs (p = 0.0096), and fewer treated episodes of ventricular tachycardia or fibrillation (VT/VF) (P = 0.050) than nonresponders. Multiple regression analysis demonstrated that responder status significantly predicted single PVCs and PVC runs. Gender was the most important predictor of treated VT/VF with females having no episodes over 6 months of follow-up.

Anatomic responders to CRT demonstrate significantly fewer single PVCs and runs of PVCs. The implication of these observations is that anatomic remodeling is linked to electrical remodeling.