Effects of Cardiac Resynchronization Therapy on Left Ventricular Mass and Wall Thickness in Mild Heart Failure Patients in MADIT-CRT.

ArticleinHeart rhythm: the official journal of the Heart Rhythm Society 10(3) · November 2012with32 Reads
Impact Factor: 5.08 · DOI: 10.1016/j.hrthm.2012.11.007 · Source: PubMed


    BACKGROUND: The influence of CRT on left ventricular wall thickness and left ventricular mass (LVM) is unknown. OBJECTIVES: To evaluate the effects of CRT on septal, posterior wall thickness (SWT, PWT) and LVM in patients with LBBB and non-LBBB as compared to ICD patients, and to assess the relationship between CRT-induced changes and cardiac events. METHODS: We investigated 843 with LBBB and 366 patients with non-LBBB, enrolled in MADIT-CRT to analyze changes in SWT, PWT and LVM at 12-month and subsequent outcome. The primary end point was heart failure (HF) or death; secondary end points included ventricular tachycardia (VT), ventricular fibrillation (VF) or death. RESULTS: In LBBB patients, reduction in SWT, PWT and LVM was more pronounced in CRT-D as compared to ICD (SWT: -6.7±4.4% vs. -1.0±1.9%; PWT:-6.4±4.3% vs. -0.8±1.9%, LVM -23.6±9.9% vs. -5.1±5.1%, p< 0.001 for all). In CRT-D patients with non-LBBB, LVM reduction was less pronounced, however the changes in SWT and PWT were comparable. Change in LVM correlated with changes in left ventricular end-diastolic volume. In CRT-D patients with LBBB, reduction in SWT, LVM was associated with reduction in HF/Death (SWT: HR=0.94, 95%CI: 0.89-0.99 per percent change, p=0.03) and VT/VF/Death (SWT: HR=0.95, 95%CI: 0.91-1.00, p= 0.04). CRT-D patients with non-LBBB did not show favorable reduction of clinical or arrhythmic end points related to changes in SWT, PWT or LVM. CONCLUSIONS: CRT-D was associated with significant reduction in SWT, PWT and LVM in patients with LBBB along with LV volume changes and associated favorable clinical and arrhythmic outcome.