Abstract 16531: Absence of Remodeling Benefit of Lv-crt Over Bv-crt in Patients With Heart Failure and Wide Qrs: Insight From the Evaluation of Resynchronization Therapy for Heart Failure (EARTH) Trial
Purpose: Cardiac Resynchronization Therapy (CRT) is recommended for patients with advanced heart failure (HF) and wide QRS, but 30% of these patients fail to respond to CRT. The EARTH trial showed similar clinical benefit with two pacing modes, LV- and BV-CRT. Nevertheless, experimental data have suggested hemodynamic and biochemical benefits of LV pacing over BV. Whether LV-CRT leads to beneficial remodeling (by echocardiography and biomarkers) over BV-CRT remains unknown.
Methods and Results: 120 patients with HF (NYHA II-IV, LVEF 35%, QRS width ≥120ms) requiring a defibrillator were randomized to CRT: Bi-ventricular (BV) versus LV pacing, in GREATER-EARTH. Echocardiography was performed using a standardized protocol; biomarkers of inflammation (HS-CRP), myocardial damage and overload (troponin & NT-proBNP) and LV remodeling/fibrosis (Osteopontin, PIIINP, matrix metalloproteinases and their inhibitor-TIMPs) were collected. After 6-months of pacing, marked reverse remodeling occurred (table), with improved diastolic dysfunction, without any difference between the two pacing modes (LV=BV). Interestingly, the interventricular delay was the only parameters of dyssynchrony improved by CRT, merely with LV-CRT; this was associated with a decrease in TIMP-4, an important HF prognostic marker.
Conclusions: BV and LV-CRT lead to similar improvement in cardiac remodelling after 6-months of pacing, without any effect on intra-LV dyssynchrony measured by echocardiography. Only LV-CRT significantly decreased the interventricular mechanical dyssynchrony and TIMP-4, an important prognostic biomarker in HF.
- © 2011 by American Heart Association, Inc.