Significant Left Ventricular Reverse Remodeling Research Articles

Left heart chambers reverse remodeling after combined CABG and mitral repair

Results The mean effective ejection fraction increased from 18 ± 6% to 39 ± 13% (p << 0.05) at the follow-up. Left ventricular end-systolic volume index decreased from 44 ± 24 ml/m2 to 39 ± 26 ml/m2 (p = 0.002). Significant left ventricular reverse remodeling (≥ 15% reduction of LVESVI) was observed in 55 % of all survivors. Recurrent IMR was detected in only 2.8% (2/71) of the evaluated patients. Left atrial volume index decreased from 43 ± 15 ml/m2 to 36 ± 14 ml/m2 (p = 0.000003) and left atrial reverse remodeling was significant for 57 % of all survivors.

Influence of Diabetes on Left Ventricular Systolic and Diastolic Function and on Long-Term Outcome After Cardiac Resynchronization Therapy

OBJECTIVEThe influence of diabetes on cardiac resynchronization therapy (CRT) remains unclear. The aims of the current study were to 1) assess the changes in left ventricular (LV) systolic and diastolic function and 2) evaluate long-term prognosis in CRT recipients with diabetes.RESEARCH DESIGN AND METHODSA total of 710 CRT recipients (171 with diabetes) were included from an ongoing registry. Echocardiographic evaluation, including LV systolic and diastolic function assessment, was performed at baseline and 6-month follow-up. Response to CRT was defined as a reduction of ≥15% in LV end-systolic volume (LVESV) at the 6-month follow-up. During long-term follow-up (median = 38 months), all-cause mortality (primary end point) and cardiac death or heart failure hospitalization (secondary end point) were recorded.RESULTSAt the 6-month follow-up, significant LV reverse remodeling was observed both in diabetic and non-diabetic patients. However, the response to CRT occurred more frequently in non-diabetic patients than in diabetic patients (57 vs. 45%, P < 0.05). Furthermore, a significant improvement in LV diastolic function was observed both in diabetic and non-diabetic patients, but was more pronounced in non-diabetic patients. The determinants of the response to CRT among diabetic patients were LV dyssynchrony, ischemic cardiomyopathy, and insulin use. Both primary and secondary end points were more frequent in diabetic patients (P < 0.001). Particularly, diabetes was independently associated with all-cause mortality together with ischemic cardiomyopathy, renal function, LVESV, LV dyssynchrony, and LV diastolic dysfunction.CONCLUSIONSHeart failure patients with diabetes exhibit significant improvements in LV systolic and diastolic function after CRT, although they are less pronounced than in non-diabetic patients. Diabetes was independently associated with all-cause mortality.

Left ventricular reverse remodeling after transcatheter aortic valve implantation: a cardiovascular magnetic resonance study.

BackgroundIn patients with severe aortic stenosis, left ventricular hypertrophy is associated with increased myocardial stiffness and dysfunction linked to cardiac morbidity and mortality. We aimed at systematically investigating the degree of left ventricular mass regression and changes in left ventricular function six months after transcatheter aortic valve implantation (TAVI) by cardiovascular magnetic resonance (CMR).MethodsLeft ventricular mass indexed to body surface area (LVMi), end diastolic volume indexed to body surface area (LVEDVi), left ventricular ejection fraction (LVEF) and stroke volume (SV) were investigated by CMR before and six months after TAVI in patients with severe aortic stenosis and contraindications for surgical aortic valve replacement.ResultsTwenty-sevent patients had paired CMR at baseline and at 6-month follow-up (N=27), with a mean age of 80.7±5.2 years. LVMi decreased from 84.5±25.2 g/m2 at baseline to 69.4±18.4 g/m2 at six months follow-up (P<0.001). LVEDVi (87.2±30.1 ml /m2vs 86.4±22.3 ml/m2; P=0.84), LVEF (61.5±14.5% vs 65.1±7.2%, P=0.08) and SV (89.2±22 ml vs 94.7±26.5 ml; P=0.25) did not change significantly.ConclusionsBased on CMR, significant left ventricular reverse remodeling occurs six months after TAVI.

Cardiac resynchronization therapy in patients with chronic heart failure is associated with anti-inflammatory and anti-remodeling effects

ObjectivesProinflammatory cytokines, matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play a role in left ventricular (LV) structural remodeling. We aimed to investigate the effects of cardiac resynchronization therapy (CRT) on serum levels of amino-terminal prohormone B-type natriuretic peptide (NT-proBNP), some interleukins (IL-1β, IL-6, IL-8), MMP-2 and TIMP-2 in patients with chronic heart failure (CHF). Design and methodsWe studied 27 patients (15 M/12 F) with CHF, III–IV NYHA class, implanted with a biventricular pacemaker/defibrillator and 40 healthy subjects (23 M/17 F). Blood samples were collected at baseline and 1week, 3, 6, and 12months after CRT device implantation. Cardiac function was assessed echocardiographically. ResultsCRT induced significant improvement in the NYHA class (baseline 3.2±0.5 vs. 1.0 at 12months, P=0.0002) and significant LV reverse remodeling, with a 41% (P=0.001) reduction in LV end-systolic volume (LVESV). This was associated with a significant reduction in serum NT-proBNP, IL-6 and IL-8. Positive extracellular matrix remodeling was illustrated by decreasing levels of MMP-2 and increasing TIMP-2. MMP-2/TIMP-2 ratio decreased with 55% (P=0.003) from baseline value at 12months and the correlation with LVESV reduction was 0.41 (P=0.001). ConclusionsStructural response to CRT is associated with reduced immune activation and positive extracellular matrix remodeling.

Comparison of left ventricular reverse remodeling induced by cardiac contractility modulation and cardiac resynchronization therapy in heart failure patients with different QRS durations

BackgroundCardiac contractility modulation (CCM) is a new device-based therapy for advanced systolic heart failure with normal QRS duration and therefore not suitable for cardiac resynchronization therapy (CRT). Left ventricular (LV) reverse remodeling was reported in patients treated with CCM or CRT, however, the extent of response was not compared. MethodsThis observational study consisted of three groups of patients with symptomatic heart failure and LV ejection fraction <35% despite optimal medical therapy. Group 1 included those received CCM with a QRS duration <120ms (n=33), Group 2 included those received CRT with a QRS duration of 120–150ms (n=43), and Group 3 included those received CRT with a QRS duration >150ms (n=56). LV end-systolic volume (LVESV) was measured at baseline and 3months later. ResultsAge, gender, etiology of heart failure and baseline ejection fraction were comparable. A significant LV reverse remodeling was observed in each group. The degree of LVESV reduction was similar between Group 1 and Group 2 (−11.3±11.8 vs. −13.6±18.3%, p=0.833), however, it was greater in Group 3 (−25.0±18.0%, both p<0.01). By using the reduction ≥15%, the responder rate was not different between Group 1 (39%) and Group 2 (42%), but significantly higher in Group 3 (68%) (χ2=9.514, p=0.009). ConclusionCCM exhibited a similar LV reverse remodeling response to CRT for patients with a mildly prolonged QRS, though the effect was less strong when compared to CRT for patients with a very wide QRS.

Acute and 12-Month Results With Catheter-Based Mitral Valve Leaflet Repair: The EVEREST II (Endovascular Valve Edge-to-Edge Repair) High Risk Study

The EVEREST II (Endovascular Valve Edge-to-Edge Repair) High Risk Study (HRS) assessed the safety and effectiveness of the MitraClip device (Abbott Vascular, Santa Clara, California) in patients with significant mitral regurgitation (MR) at high risk of surgical mortality rate. Patients with severe MR (3 to 4+) at high risk of surgery may benefit from percutaneous mitral leaflet repair, a potentially safer approach to reduce MR. Patients with severe symptomatic MR and an estimated surgical mortality rate of ≥12% were enrolled. A comparator group of patients screened concurrently but not enrolled were identified retrospectively and consented to compare survival in patients treated by standard care. Seventy-eight patients underwent the MitraClip procedure. Their mean age was 77 years, >50% had previous cardiac surgery, and 46 had functional MR and 32 degenerative MR. MitraClip devices were successfully placed in 96% of patients. Protocol-predicted surgical mortality rate in the HRS and concurrent comparator group was 18.2% and 17.4%, respectively, and Society of Thoracic Surgeons calculator estimated mortality rate was 14.2% and 14.9%, respectively. The 30-day procedure-related mortality rate was 7.7% in the HRS and 8.3% in the comparator group (p = NS). The 12-month survival rate was 76% in the HRS and 55% in the concurrent comparator group (p = 0.047). In surviving patients with matched baseline and 12-month data, 78% had an MR grade of ≤2+. Left ventricular end-diastolic volume improved from 172 ml to 140 ml and end-systolic volume improved from 82 ml to 73 ml (both p = 0.001). New York Heart Association functional class improved from III/IV at baseline in 89% to class I/II in 74% (p < 0.0001). Quality of life was improved (Short Form-36 physical component score increased from 32.1 to 36.1 [p = 0.014] and the mental component score from 45.5 to 48.7 [p = 0.065]) at 12 months. The annual rate of hospitalization for congestive heart failure in surviving patients with matched data decreased from 0.59 to 0.32 (p = 0.034). The MitraClip device reduced MR in a majority of patients deemed at high risk of surgery, resulting in improvement in clinical symptoms and significant left ventricular reverse remodeling over 12 months. (Pivotal Study of a Percutaneous Mitral Valve Repair System [EVEREST II]; NCT00209274)

The extent of early left ventricular reverse remodelling is related to midterm outcomes after restrictive mitral annuloplasty in patients with non-ischaemic dilated cardiomyopathy and functional mitral regurgitation

Restrictive mitral annuloplasty (RMA) can often improve heart failure symptoms and induce left ventricular (LV) reverse remodelling in patients with non-ischaemic dilated cardiomyopathy (DCM) and functional mitral regurgitation. However, it is unknown whether the observed LV reverse remodelling translates into better outcomes or not. Fifty patients with advanced non-ischaemic DCM (age, 64 ± 10 years, 74% men) underwent RMA and were followed up with a mean of 2 years. Preoperatively, all had 3 to 4+ functional mitral regurgitation (MR), an ejection fraction (EF) of 26 ± 8.6 %, an indexed LV end-systolic volume (LVESVI) of 112 ± 47 ml/m(2). All patients received complete semi-rigid undersized ring annuloplasty. Correlations between early reduction in LVESVI at 1 month after the operation and mid-term clinical outcomes were analysed. There was no 30-day mortality. LVESVI significantly decreased to 96 ± 53 ml/m(2) and LVEF improved to 31 ± 15%. During follow-up, 16 (32%) recurred heart failure, of whom 7 (14%) died. The receiver operating characteristic (ROC) curve found that a reduction in LVESVI >8.3% had a sensitivity of 80% and a specificity of 78% in predicting all adverse events. With this cut-off value, there were 30 (60%) responders to reverse remodelling. Responders had significantly better survival (96.4 versus 68.7%, P = 0.007) and freedom from heart failure rate (85.4 versus 31.8%, P = 0.0003) than non-responders at 3 years. In a 1-year follow-up echocardiographic study, non-responders had shown no significant LV reverse remodelling with greater degree of residual MR than responders. The extent of early LV reverse remodelling is related to mid-term mortality, heart failure events and late reverse remodelling and repair durability after RMA for non-ischaemic DCM.

Prediction of Response to Cardiac Resynchronization Therapy Combining Two Different Three-Dimensional Analyses of Left Ventricular Dyssynchrony

Triplane tissue synchronization imaging (TSI) and real-time 3-dimensional echocardiography (RT3DE) provide different characterizations of left ventricular (LV) mechanics and dyssynchrony. Triplane TSI assesses differences in time to peak systolic segmental myocardial tissue velocities, whereas RT3DE evaluates differences in time to minimum end-systolic regional volumes. Whether an approach using the 2 3D techniques predicts better significant reverse remodeling after cardiac resynchronization therapy (CRT) remains unknown. In 166 patients (mean age 66 ± 9 years, 78% men) treated with CRT, baseline LV dyssynchrony was assessed using RT3DE and triplane TSI. LV dyssynchrony was defined by a systolic dyssynchrony index ≥6.4% when assessed with RT3DE and SD of time to peak velocity of 12 segments (Ts-SD-12) ≥33 ms with triplane TSI. CRT response was defined by ≥15% decrease in LV end-systolic volume at 6-month follow-up. Mean LV dyssynchrony using Ts-SD-12 was 48 ± 26 ms and mean systolic dyssynchrony index was 8.51 ± 3.81%. Response to CRT was observed in 86.3% of patients showing LV dyssynchrony with the 2 methods. In contrast, 97% of patients who did not show significant LV dyssynchrony with any of the techniques were nonresponders (p <0.001). Importantly, systolic dyssynchrony index and LV dyssynchrony using Ts-SD-12 were independent predictors of response to CRT (p <0.001 for each technique). Assessment of LV dyssynchrony with the 2 techniques showed incremental value for prediction of significant LV reverse remodeling over its assessment with only 1 technique (chi-square 90.18, p <0.001). In conclusion, the combined use of 2 different 3D techniques to assess LV dyssynchrony permits accurate prediction of response to CRT.

Relationship between mechanical and electrical remodelling in patients with cardiac resynchronization implanted defibrillators

Cardiac resynchronization therapy (CRT) is associated with reverse left ventricular (LV) remodelling. However, the effects of CRT-induced mechanical remodelling on electrical remodelling, and the occurrence of ventricular arrhythmias have not been clearly established. We studied the relationship between mechanical remodelling, electrical remodelling, and the occurrence of appropriate implantable cardioverter-defibrillator (ICD) therapy 1 year after CRT. We analysed data from 45 patients who underwent ICD-CRT implantation at our centre. Significant LV reverse remodelling was defined by a minimum 10% decrease in the LV end-diastolic diameter (LVEDd) at 1 year of follow-up. Electrocardiographic indices of dispersion of repolarization [QTc, Tpeak-Tend (Tp-e) and their dispersion] were measured immediately and 1 year post-CRT implantation. The occurrence of appropriate ICD therapy was noted for each patient. Patients with (n= 21) and without (n= 24) significant LV reverse remodelling had similar baseline characteristics. At 1 year of follow-up, patients with mechanical reverse LV remodelling exhibited a significant decrease in QTc (505 ± 42 vs. 485 ± 52 ms, P < 0.05) and Tp-e (107 ± 26 vs. 92 ± 22 ms, P < 0.0001). However, patients without mechanical LV reverse remodelling exhibited a significant increase in QT dispersion (29 ± 43 vs. 98 ± 47 ms, P = 0.002) and Tp-e dispersion (22 ± 21 vs. 54 ± 36 ms, P = 0.0001). Finally patients with mechanical LV reverse remodelling experienced a lower rate of ICD therapy (P = 0.0025) after a mean follow-up of 19 months. Reverse LV mechanical remodelling is associated with reversal of electrical remodelling and a lower rate of appropriate ICD therapy following CRT.

Pulmonary hypertension predicts adverse cardiac events after restrictive mitral annuloplasty for severe functional mitral regurgitation

Pulmonary hypertension (PH) is an indicator of a poor prognosis in patients with dilated cardiomyopathy. Few studies have investigated the prognostic role of PH in patients undergoing restrictive mitral annuloplasty (RMA) for severe functional mitral regurgitation secondary to advanced cardiomyopathy. A total of 46 patients undergoing RMA were classified into 3 groups on the basis of the Doppler-derived systolic pulmonary artery pressure (PAP) at baseline. Of the 46 patients, 19 had a systolic PAP less than 40 mm Hg (mild PH group), 17 had a systolic PAP of 40 to 60 mm Hg (moderate PH group), and 10 had a systolic PAP greater than 60 mm Hg (severe PH group). Postoperative cardiac catheterization showed that the RMA procedure resulted in a significant reduction of the left ventricular (LV) preload and improvements in LV systolic function in all 3 groups, along with the relief of symptoms. During the follow-up period (mean, 36 ± 19 months), cardiac death occurred in 6 patients, readmission because of heart failure in 3, and fatal arrhythmia in 1. The rate of freedom from these cardiac events at 3 years was 93% ± 7%, 88% ± 8%, and 56% ± 17% in the mild, moderate, and severe PH groups (P < .001). Serial echocardiography showed that significant LV reverse remodeling occurred in 89%, 71%, and 25% of the mild, moderate, and severe PH groups, respectively. Multivariate Cox regression analysis identified severe PH (systolic PAP > 60 mm Hg) as a significant predictor of adverse cardiac events, as well as LV remodeling after RMA. Noninvasive assessment of preoperative PH has a prognostic value in patients undergoing RMA for severe functional mitral regurgitation secondary to advanced cardiomyopathy.

197 Reversal mechanical remodeling is associated with reversal of electrical remodeling and reduction in appropriate therapy in patients with cardiac resynchronization implanted defibrillators

Cardiac Resynchronization Therapy (CRT) is associated with reverse left ventricular (LV) remodeling. However, the effects of CRT induced mechanical remodeling on electrical remodeling, and the occurrence of ventricular arrhythmias has not been clearly established. We studied the relationship between mechanical remodeling, electrical remodeling and the occurrence of appropriate implantable cardioverter defibrillator (ICD) therapy one year after CRT. We analyzed data from 45 patients who underwent ICD-CRT implantation at our center. Patients had New York Heart Association (NYHA) functional class III or IV heart failure symptoms, left ventricular ejection fraction (LVEF) 35%, and QRS duration 120 ms or QRS <120 ms with left intraventricular dyssynchrony. Significant LV reverse remodeling was defined by a minimum 10% decrease in the LV end diastolic diameter (LVEDd) at one year of follow-up. Electrocardiographic indices of dispersion of repolarization (DR) (QTc, Tpeak-Tend (Tp-e) and their dispersion) were measured immediately and one year post-CRT implantation. The occurrence of appropriate ICD therapy was noted for each patient. Patients with (n = 21) and without (n = 24) significant LV reverse remodeling had similar baseline characteristics. At one year of follow-up, patients with reverse LV remodeling exhibited both a significant decrease in DR parameters and a lower rate of ICD therapy (p = 0.0025). Reverse LV mechanical remodeling is associated with reversal of electrical remodeling and a lower rate of appropriate ICD therapy following CRT.

Prevalence and characteristics of patients with clinical improvement but not significant left ventricular reverse remodeling after cardiac resynchronization therapy

Although most patients who improve in clinical status after cardiac resynchronization therapy (CRT) also show a significant left ventricular (LV) reverse remodeling, some patients do not show echocardiographic improvement. The aim of the present study was to evaluate the degree of agreement between clinical and echocardiographic response to CRT in a large cohort of heart failure patients, and to evaluate the characteristics of patients with clinical response but without echocardiographic response. In 440 consecutive heart failure patients (mean age 66 ± 11 years, 81% men) treated with CRT, agreement between clinical and echocardiographic responses at 6 months of follow-up were evaluated. The combined clinical response was defined as: ≥1-point New York Heart Association functional class improvement or ≥15% increase in 6-minute walk test. Echocardiographic response was defined by a reduction in LV end-systolic volume (LVESV) ≥15%. At 6 months of follow-up, clinical response was observed in 84% (n = 370) of the patients. Significant reduction in LVESV was noted in 63% (n = 276). The majority of patients who improved clinically did show LV reverse remodeling (72%, n = 268). Importantly, 28% (n = 102) of patients who improved clinically did not show significant LV reverse remodeling. The patients with clinical response but without echocardiographic response had more often ischemic heart failure as compared to patients with positive clinical and echocardiographic response (69.6% vs 57.5%; P = .021). Moreover, patients with such discordant responses had more narrow QRS complex (148 ± 31 vs 159 ± 31 milliseconds; P = .004), and showed less LV dyssynchrony than patients with concordant positive responses (90 ± 77 vs 171 ± 105 milliseconds; P < .001). Although there is a good concordance between echocardiographic and clinical response to CRT, up to 28% of the population experienced clinical response without significant LV reverse remodeling. Subjects with such discrepant responses have more frequently ischemic heart failure and show more narrow QRS complex and less LV dyssynchrony than patients with both clinical and echocardiographic response.

Optimal Left Ventricular Lead Position Predicts Reverse Remodeling and Survival After Cardiac Resynchronization Therapy

Abstract. Objectives. The aim of the current study was to evaluate echocardiographic parameters after 6 months of cardiac resynchronization therapy (CRT) as well as long‐term outcome in patients with the left ventricular (LV) lead positioned at the site of latest activation (concordant LV lead position) as compared with that seen in patients with a discordant LV lead position.Background. A nonoptimal LV pacing lead position may be a potential cause for nonresponse to CRT.Methods. The site of latest mechanical activation was determined by speckle tracking radial strain analysis and related to the LV lead position on chest x‐ray in 244 CRT candidates. Echocardiographic evaluation was performed after 6 months. Long‐term follow‐up included all‐cause mortality and hospitalizations for heart failure.Results. Significant LV reverse remodeling (reduction in LV end‐systolic volume from 189±83 mL to 134±71 mL, P&lt;.001) was noted in the group of patients with a concordant LV lead position (n=153, 63%), whereas patients with a discordant lead position showed no significant improvements. In addition, during long‐term follow‐up (32±16 months), less events (combined for heart failure hospitalizations and death) were reported in patients with a concordant LV lead position. Moreover, a concordant LV lead position appeared to be an independent predictor of hospitalization‐free survival after long‐term CRT (hazard ratio: 0.22, P=.004).Conclusions. Pacing at the site of latest mechanical activation, as determined by speckle tracking radial strain analysis, resulted in superior echocardiographic response after 6 months of CRT and better prognosis during long‐term follow‐up.

Left Ventricular Pacing Lead Positioning in the Target Vein of the Coronary Sinus: Description of a Challenging Case

The optimal left ventricular pacing location for cardiac resynchronization therapy should be individualized according to the site of maximal mechanical delay. However, the presence of vein stenosis or kinking in coronary sinus (CS) anatomy could hamper lead implantation in the target vessel. We describe the case of a patient with dilated cardiomyopathy and a dual-chamber pacemaker referred for upgrading to a biventricular device owing to New York Heart Association III heart failure symptoms. Tissue Doppler analysis before implantation showed that the area of maximum activation delay was located in the posterolateral region of the left ventricle. Insertion of the lead into a posterolateral vein of the CS by means of the standard over-the-wire approach was unsuccessful due to the presence of a stenosis at the ostium of the vein. Lead placement in an anterior vein of the CS was unsatisfactory owing to a poor local delay from QRS onset. After balloon vein angioplasty, the pacing lead passed through the stenotic tract at the ostium of the target vein and was successfully positioned in the posterolateral region. Three months after pacemaker implantation, echocardiography showed an important reduction in the indexes of both inter- and intraventricular asynchrony and a significant left ventricular reverse remodeling.

Abstract 3355: Relationship Between Electrocardiographic Remodeling, Mechanical Remodeling and the Occurrence of Appropriate Therapy in Biventricular Implantable Cardioverter Defibrillator Patients

Background: Cardiac Resynchronization Therapy (CRT) is associated with reverse left ventricular (LV) remodeling. However, the effect of CRT on electrical remodeling, reverse mechanical remodeling, occurrence of ventricular arrhythmias is not well established. Methods: D ata from 45 patients who underwent implantable cardioverter defibrillator(ICD)-CRT implantation was retrospectively analyzed. Patients had New York Heart Association (NYHA) functional class III or IV heart failure symptoms, left ventricular ejection fraction (LVEF) &lt;35%, and QRS duration &gt;130 ms or QRS ≤130ms with left intraventricular dyssynchrony. Significant LV reverse remodeling was defined by a decrease of left ventricular end diastolic diameter (LVEDd) by at least 10% after 1 year of follow up. Electrocardiographic indices of dispersion of repolarization (DR) (QTc, T peak-Tend (Tp-e) and their dispersion) were measured immediately and 1 year after implantation. The occurrence of appropriate ICD therapy was noted for each patient. Results: Patients with significant LV reverse remodeling (n=21) and without LV reverse remodeling (n=24) had similar baseline characteristics. After one year of follow up, patients with LV reverse remodeling exhibited a significant decrease in DR parameters (Tp-e, QT dispersion and Tp-e dispersion), and lower rate of appropriate ICD therapy (log rank p=0.002), compared to those without reverse remodeling who experienced an increase in DR parameters (QT dispersion and Tp-e dispersion), figure 1 . Conclusion: Mechanical LV reverse remodeling is associated with an electrical reverse remodelling and a lower rate of appropriate ICD therapy. Figure 1: Occurence of appropriate CD therapy according to LV reverse remodelling

Effect of Cardiac Resynchronization Therapy in Patients with Moderate Left Ventricular Systolic Dysfunction and Wide QRS Complex: A Prospective Study

We sought to investigate the effect of cardiac resynchronization therapy (CRT) on disease progression in patients with moderate left ventricular (LV) systolic dysfunction. This is a prospective study to explore the effect of CRT in 15 optimally treated patients (age: 66.1 +/- 12.8 years; male = 13) with New York Heart Association (NYHA) class III, LV ejection fraction >35% and <45% and QRS duration >120 msec. Echocardiographic examination and standard heart failure assessment was performed before and 3 months after CRT implantation. The magnitude of echocardiographic remodeling measurements was compared with 30 age, sex, NYHA class, and heart failure etiology matched patients with conventional CRT indication. There were significant reductions in LV end-systolic (86.2 +/- 24.1 to 69.7 +/- 22.2 mL, P < 0.01)/end-diastolic (135.5 +/- 36.8 to 120.5 +/- 34.6 mL, P < 0.01) volumes, improvement in LV ejection fraction (39.1 +/- 2.2 to 44.2 +/- 5.5%, P = 0.01), and NYHA class (3.0 +/- 0.0 to 2.07 +/- 0.46, P < 0.001). There was no difference in changes in LV volumes, ejection fraction, NYHA class, and exercise capacity before and after CRT between the study and conventional groups except for greater improvement in the quality of life score in the conventional group. In this prospective study, significant LV reverse remodeling by CRT in those with a wide QRS complex and moderate LV systolic dysfunction was observed. Further studies to explore the benefit of CRT in patients with less severe heart failure are recommended.