Impact of Mitral Regurgitation and Myocardial Viability on Left Ventricular Reverse Remodeling After Cardiac Resynchronization Therapy in Patients With Ischemic Cardiomyopathy

Abstract

This study investigated the impact of ischemic mitral regurgitation (MR) severity and viability on left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) in patients with ischemic cardiomyopathy. Severe MR and ischemic cardiomyopathy have been associated with lack of LV reverse remodeling after CRT. Fifty-seven consecutive patients with ischemic MR, LV ejection fraction <35%, QRS duration >120 ms, and intraventricular dyssynchrony >50 ms were prospectively included. Stress echocardiography was performed before CRT implantation. Viability in the region of the LV pacing lead was defined as the presence of viability in 2 contiguous segments. Response to CRT at 6 months was defined by evidence of >15% LV decrease in end-systolic volume. Severe MR was defined by an effective regurgitant orifice (ERO) area >20 mm 2 . Thirtythree patients (58%) were responders at follow-up. Baseline ERO area and prevalence of severe MR were not different between responders and nonresponders (19 ؎ 11 vs 21 ؎ 13 mm 2 , p ‫؍‬ 0.67; 52% vs 53%, p ‫؍‬ 0.84). In responders, MR was decreased by 58% (ERO 19 ؎ 12 to 8 ؎ 6 mm 2 ). In the presence of viability in the region of the pacing lead, 74% (n ‫؍‬ 29 patients) were responders (sensitivity 88%, specificity 58%); in the subgroup of patients with viability in the region of the pacing lead and severe MR, 83% (n ‫؍‬ 17 patients) were responders. In conclusion, LV remodeling is frequent and ischemic MR decrease important in patients with viability in the region of the pacing lead without regard to MR severity. © 2010 Elsevier Inc. All rights reserved. (Am J Cardiol 2010;106:31-37) Ischemic heart disease is the most common cause of systolic left ventricular (LV) dysfunction. The prognosis of these patients is particularly modulated by the extent of residual viable myocardium. Cardiac resynchronization therapy (CRT) improves LV function and geometry, exercise capacity, and outcomes of appropriately selected patients with heart failure.1-3 CRT leads to a decrease in mitral regurgitation (MR) severity at rest and during exercise by an increase of LV function and local synchronicity (decrease in mechanical activation delay of papillary muscles). 4 -11 Response to CRT largely depends on extent of LV dyssynchrony, severity of LV remodeling, extent of scar tissue, and possibility offered to the left ventricle to recruit function (contractile reserve). Whether the presence of MR and its severity could modulate the response to CRT is still controversial. Several investigators have suggested that extent of LV reverse remodeling could be lessened in patients with significant MR, particularly in the setting of ischemic cardiomyopathy. [12][13][14] This study investigated the potential impact of MR severity and myocardial contractile reserve on acute and long-term responses to CRT in patients with ischemic cardiomyopathy and significant LV dyssynchrony. MethodsFrom May 2005 to March 2008, 57 patients (mean age 71 Ϯ 8 years, 43 men, (75%) were prospectively enrolled in the Inst...

Sex Differences in Device Therapy for Heart Failure: Utilization, Outcomes, and Adverse Events

“…13,19, Two authors were contacted for data clarification and did not respond; therefore, these studies were excluded from the results. 103,106 Of these 100 articles, 56 included comparisons of means or risk ratio estimates of effectiveness analyses of improvement in NYHA heart failure class, ejection fraction, and left ventricular volumes. 19,21,24,25,107 Twenty-two articles discussed sex-specific outcomes for hospitalization and death 44,[50][51][52][79][80][81][82][83][84]110 or death alone, 19,28,[85][86][87][88][89][90][91][92][93][94]114,[116][117][118] 2 included device-related complications, 120,121 and 20 included baseline characteristics stratified by sex (Fig.…”

Mechanistic Features Associated With Improvement in Mitral Regurgitation After Cardiac Resynchronization Therapy and Their Relation to Long-Term Patient Outcome

“…20 Hung et al 36 used an animal model to demonstrate that scar at the site of the papillary muscle insertion was directly related to ischemic MR, and that repositioning of the papillary muscle may reduce MR without compromising LV function. Other factors related to MR and unfavorable outcome in patients with CRT include global scar burden, 5,37 and scar at the site of the LV lead, 6,38,39 which may be related to scar at the papillary muscle insertion sites. Our present study combines the important elements of baseline dyssynchrony, lack of excessive LV dilatation, and lack of scar at the papillary muscle insertion site as factors that are independently associated with improvements in MR, and combine them in a unique scoring system.…”

A Pilot Study of Systolic Dyssynchrony Index by Real Time Three‐Dimensional Echocardiography and Doppler Tissue Imaging Parameters Predicting the Hemodynamic Response to Biventricular Pacing in the Early Postoperative Period after Cardiac Surgery

“…It has been published that BIV pacing in patients with poor LV function and bundle branch block is associated with improved CO, coronary flow, and diastolic function 19,20 . This mode of pacing may improve volumetric and functional echocardiographic parameters and may lead to LV reverse remodeling with a reduction of mitral regurgitation grade 21 . The prognosis of cardiac surgery patients deteriorates proportionately with the degree of LV dysfunction and a history of clinically overt heart failure 22 .…”

“…This may arise on the basis of scars, fibrosis, or even viable‐stunned myocardium and may be further complicated by excessive chamber filling based on the Starling law. Some authors have recently recommended investigating myocardial viability and contractile reserve as a complement to DTI parameters for better prediction of the response to CRT 21 . Other studies have used magnetic resonance imaging and gated myocardial perfusion single‐photon emission computed tomography (GMPS) for assessing LV dyssynchrony and for predicting the response to CRT 30,31 .…”