Impact of reduction in early- and late-systolic functional mitral regurgitation on reverse remodelling after cardiac resynchronization therapy.
OBJECTIVE
To examine whether the presence of pre-pacing functional mitral regurgitation (MR) and its improvement would affect the extent of left ventricular (LV) reverse remodelling after cardiac resynchronization therapy (CRT).


RESULTS
Echocardiographic assessment was performed in 83 patients before and 3 months after CRT. Total MR volume and the early- and late-systolic MR flow rate were assessed. At 3 months, there was reduction in total MR volume (38 ± 20 vs. 33 ± 21 mL) with decrease in both early- (71 ± 52 vs. 60 ± 51 mL/s) and late-systolic (49 ± 46 vs. 42 ± 46 mL/s) MR flow rate (all P < 0.05). Receiver-operating characteristic curve found that an 11% decrease in total MR volume was associated with LV reverse remodelling [defined by the reduction in LV end-systolic volume (LVESV) of ≥15%] [sensitivity, 90%; specificity, 80%; area under the curve (AUC), 0.85; P < 0.001]. The improvement in early- and late-systolic MR was also associated with LV reverse remodelling, in which improvement in early-systolic MR had higher sensitivity, specificity, and AUC than late-systolic MR. The extent of reverse remodelling with gain in LV ejection fraction and forward stroke volume was greatest in patients with improvement in total MR, intermediate in those with mild or no MR at baseline, and the least in those without improvement in total MR (LVESV, -29.8 ± 12.0 vs. -18.6 ± 16.6 vs. -5.5 ± 8.6%; ejection fraction, 11.8 ± 6.2 vs. 7.0 ± 6.8 vs. 3.0 ± 5.0%; forward stroke volume, 43.1 ± 37.9 vs. 21.1 ± 26.1 vs. 6.8 ± 34.6%; all P < 0.05).


CONCLUSIONS
Improvement of functional MR contributes to LV reverse remodelling after CRT, whereas reduction of early-systolic MR is more powerful than late-systolic MR.
Liang
Yu-Jia
YJ
Division of Cardiology, Department of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, Institute of Vascular Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
Zhang
Qing
Q
Fung
Jeffrey Wing-Hong
JW
Chan
Joseph Yat-Sun
JY
Yip
Gabriel Wai-Kwok
GW
Lam
Yat-Yin
YY
Yu
Cheuk-Man
CM
D000368:Aged; D058406:Cardiac Resynchronization Therapy; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000628:therapy*; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D012372:ROC Curve; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000502:physiology*