Longer Left Ventricular Electric Delay Reduces Mitral Regurgitation After Cardiac Resynchronization Therapy

Abstract

Background-Mitral regurgitation (MR) is associated with worse survival in those undergoing cardiac resynchronization therapy (CRT). Left ventricular (LV) lead position in CRT may ameliorate mechanisms of MR. We examine the association between a longer LV electric delay (QLV) at the LV stimulation site and MR reduction after CRT. Methods and Results-QLV was assessed retrospectively in 426 patients enrolled in the SMART-AV study (SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in CRT). QLV was defined as the time from QRS onset to the first large peak of the LV electrogram. Linear regression and logistic regression were used to assess the association between baseline QLV and MR reduction at 6 months (absolute change in vena contracta width and odds of ≥1 grade reduction in MR). At baseline, there was no difference in MR grade, LV dyssynchrony, or LV volumes in those with QLV above versus below the median (95 ms). After multivariable adjustment, increasing QLV was an independent predictor of MR reduction at 6 months as reflected by an increased odds of MR response (odds ratio: 1.13 [1.03-1.25]/10 ms increase QLV; P=0.02) and a decrease in vena contracta width (P<0.001). At 3 months, longer QLV (≥median) was associated with significant decrease in LV end-systolic volume (∆LV end-systolic volume −28.2±38.9 versus −4.9±33.8 mL, P<0.001). Adjustment for 3-month ΔLV end-systolic volume attenuated the association between QLV and 6-month MR reduction. Conclusions-In patients undergoing CRT, longer QLV was an independent predictor of MR reduction at 6 months and associated with interval 3-month LV reverse remodeling. These findings provide a mechanistic basis for using an electrictargeting LV lead strategy at the time of CRT implant. (Circ Arrhythm Electrophysiol. 2016;9:e004346.

Location, Location, Location: A Pilot Study to Compare Electrical with Echocardiographic-Guided Targeting of Left Ventricular Lead Placement in Cardiac Resynchronisation Therapy

“…There has been growing interest in the utilisation of electrical parameters for LV lead placement. Retrospective analysis of the SMART-AV trial suggested that prolonged QLV was a predictor of superior response in terms of reduction in mitral regurgitation 6 months post-implant and improvement in echocardiographic remodelling measures at 3 months [18]. A similar retrospective analysis of a single-centre study's CRT database over nine years also showed a similar association between prolonged QLVs and predicting heart failure hospitalisation and mortality [19].…”

Echocardiography‐ versus intracardiac electrocardiogram‐based optimization of cardiac resynchronization therapy: A systematic review

“…Optimized delays are demonstrated by mitral inflow velocity or LVOT VTI, which are obtained by Doppler echocardiography (Gorcsan et al, 2008; Jansen et al, 2006; Trifunović et al, 2009; Waggoner et al, 2008). The ideal LVOT delay shows maximum VTI upon programming, and the ideal AV delay shows E and A waves on transmitral inflow Doppler signals (Chatterjee et al, 2016). This modality has several advantages, including its noninvasive character, precision, and good clinical outcomes.…”

Outcomes following transcatheter repair in patients with functional mitral regurgitation not receiving guideline directed medical therapy in Israel

“…Management of patients with HF and severe FMR consists of optimizing medical therapy as first line therapy. Furthermore GDMT and cardiac resynchronization therapy may improve FMR and preclude the need for an invasive TEER procedure [ 14 , 15 ].…”