Predictors of Reduction in Mitral Regurgitation in Patients Undergoing Cardiac Resynchronization Treatment

¹ Cardiac Non Invasive Lab, Division of Cardiology, Cedars Sinai Medical Center, UCLA School of Med., United States
² Division of Cardiology, Cedars Sinai Medical Center, UCLA School of Med., United States
³ Loma Linda University Medical Center, California, United States
⁴ Division of Cardiology, Cedars Sinai Medical Center, United States

^* To whom correspondence should be addressed. E-mail: tasneem.naqvi{at}cshs.org.

Accepted 4 March 2008

	Abstract

Objectives: We evaluated echocardiographic predictors of significant reduction in functional mitral regurgitation (MR) by cardiac resynchronization treatment (CRT).

Background: CRT causes reduction in MR due to left ventricular (LV) remodeling, but determinants of clinically meaningful MR reduction acutely after CRT have not been evaluated.

Methods: Thirty five patients with > moderate to severe MR underwent CRT if significant echocardiographic mechanical dyssynchrony was present. Significant reduction in MR post CRT was defined as reduction to less than moderate MR (MR jet area/left atrial area <25% - Gp I) on follow-up echocardiogram at 1.7±2.8 months post CRT.

Results: Significant MR reduction of 62±28% from baseline MR occurred in 18 patients (Gp I) vs. 22±16% in the remaining patients (Gp II), p<0.01). Follow up LVEF was 0.43±0.09 in Gp I patients vs. 0.29±0.1% in Gp II patients (p<0.001). On multivariate analysis, time to peak strain in the mid inferior segment was the only significant predictor of response to CRT (p=0.008, OR=1.023 (CI 1.006-1.041). The sensitivity and specificity of the combined variable of time to peak strain of >400 ms in the mid inferior segment and peak negative strain of >9 and 8 % in the basal and mid posterior segments respectively to predict follow up MR was 88% and 93% respectively and positive and negative predictive value was 94% and 87%.

Conclusion: In patients with cardiomyopathy and significant MR, presence of delayed longitudinal strain in the mid inferior LV segment along with preserved negative systolic strain in the basal and mid posterior segments predicts substantial reduction in MR severity post CRT.