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Circulation: Arrhythmia and Electrophysiology
Although cardiac resynchronization therapy (CRT) may reduce functional mitral regurgitation (MR) in some patients with heart failure and reduced ejection fraction, the role of optimization of lead position on MR reduction is unclear. In this substudy, the authors found that longer LV electric delay at the LV stimulation site was associated with greater MR reduction and reverse remodeling after CRT. These findings suggest that optimization of LV lead placement may contribute to reduction in MR after CRT.
Longer Left Ventricular Electric Delay Reduces Mitral Regurgitation After Cardiac Resynchronization Therapy: Mechanistic Insights from the SMART-AV Study (SmartDelay Determined AV Optimization)
A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy
Neal A. Chatterjee, MD Michael R. Gold, MD, PhD Alan D. Waggoner, MHS Michael H. Picard, MD Kenneth M. Stein, MD Yinghong Yu, MS Timothy E. Meyer, PhD Nicholas Wold, MS Kenneth A. Ellenbogen, MD Jagmeet P. Singh, MD, PhD
Correspondence to: Jagmeet P. Singh, MD, PhD, Cardiac Arrhythmia Service, Massachusetts General Hospital Heart Center, GRB 109, 55 Fruit St, Boston, MA 02411. E-mail email@example.com
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, …