Abstract 1890: Reverse Anatomical Remodeling after Resynchronization is Associated with Reduced Ventricular Arrhythmias
Background: Cardiac resynchronization therapy (CRT) has become an effective means of reversing anatomical remodeling, improving hemodynamics, and improving the neurohormonal profile. In addition, left ventricular remodeling correlates with ventricular arrhythmias in congestive heart failure (CHF) patients. This analysis investigates the association between reverse remodeling and ventricular arrhythmias in a multicenter randomized study.
Methods: A retrospective analysis was performed of the Medtronic InSync III Marquis study, which randomized 238 biventricular (BiV) ICD pts [mean age 67 ± 10, 78% male] to optimized BiV timing vs. simultaneous BiV pacing. All patients presented with NYHA class III–IV CHF, LV ejection fraction ≤35%, and LV end-diastolic diameter ≥55 mm. Echocardiograms were obtained at baseline and 6 months post implant to measure the anatomic response to CRT, defined as LV end-systolic volume (LVESV) reduction of at least 15%. Effective anatomical remodeling was analyzed for correlation to baseline characteristics and ventricular arrhythmias recorded in the ICD diagnostics.
Results: Reverse anatomical remodeling occurred in 71/198 (3 patients were missing device data). The only significant differences in baseline data were responders had a higher proportion of non-ischemic cardiomyopathy pts (34% vs. 15%, p<0.05) and more female pts (30% vs. 15%, p <0.05) than non-responders. After 6 months, responders had on average 29% fewer counts of single premature ventricular beats (PVCs) (p=0.0001), 48% fewer PVC runs (p=0.0096), and fewer VT and VF episodes than non-responders (p=0.05). In multiple regression models, only responder status predicted number of PVCs and PVC runs.
Anatomic responders to CRT demonstrate significantly fewer single PVCs and runs of PVCs.
Anatomic responders demonstrate fewer VT/VF episodes.
The inference of these observations is that anatomic remodeling may lead to electrical remodeling.