***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background —In EchoCRT , a r and omized controlled trial evaluating the effect of  cardiac resynchronization therapy ( CRT ) in patients with a QRS duration of < 130 ms and echocardiographic evidence of left ventricular dyssynchrony , the primary outcome ( death from any cause or first hospitalization for worsening heart failure ) occurred more frequently in the CRT-ON when compared with the control group . In this prespecified subgroup analysis , we evaluated the effect of sex on clinical outcome in EchoCRT . Methods and Results —In EchoCRT , 585 ( 72 % ) of included patients were men . At baseline , male patients had a higher incidence of ischemic cardiomyopathy and longer QRS duration . On uni- and multivariable analysis , no significant interaction was observed regarding sex for the primary or any of the secondary end points . Numerically , a higher all-cause mortality was observed in male patients r and omized to CRT-ON versus CRT-OFF on univariable analysis ( hazard ratio , 1.83 ; 95 % confidence interval , 1.08–3.12 ) ; however , no statistically significant interaction compared with females r and omized to CRT-ON versus CRT-OFF was noted ( hazard ratio , 0.99 ; P interaction , 0.56 ) . There was no difference in the primary safety end point of system-related complications , including CRT system- and implantation-related events . Conclusions —The largest hazard for all-cause mortality in EchoCRT was observed in men r and omized to CRT-ON ; the comparison with women did not reach statistical significance , which may be because of the premature termination of the trial and the limited data . These results suggest that male sex may be a risk factor for harm by CRT in patients with narrow QRS width , an observation which deserves further investigation . Clinical Trial Registration —URL : https:// clinical trials.gov . Unique identifier : NCT00683696 BACKGROUND Some studies have suggested that women respond differently to cardiac resynchronization therapy ( CRT ) . We sought to determine whether female gender influences long-term clinical outcome , symptomatic response as well as echocardiographic response after CRT . METHODS AND RESULTS A total of 550 patients ( age 70.4 ± 10.7 yrs [ mean ± st and ard deviation ] ) were followed up for a maximum of 9.1 years ( median : 36.2 months ) after CRT-pacing ( CRT-P ) or CRT-defibrillation ( CRT-D ) device implantation . Outcome measure included mortality as well as unplanned hospitalizations for heart failure or major adverse cardiovascular events ( MACE ) . Female gender predicted survival from cardiovascular death ( hazard ratio [ HR ] : 0.52 , P = 0.0051 ) , death from any cause ( HR : 0.52 , P = 0.0022 ) , the composite endpoints of cardiovascular death /heart failure hospitalizations ( HR : 0.56 , P = 0.0036 ) and death from any cause/hospitalizations for MACE ( HR : 0.67 , P = 0.0214 ) . Female gender predicted death from pump failure ( HR : 0.55 , P = 0.0330 ) but not sudden cardiac death . Amongst the 322 patients with follow-up echocardiography , left ventricular ( LV ) reverse remodelling ( ≥ 15 % reduction in LV end-systolic volume ) was more pronounced in women ( 62 % vs 44 % , P = 0.0051 ) . In multivariable Cox proportional hazards analyses , the association between female gender and cardiovascular survival was independent of age , LV ejection fraction , atrial rhythm , QRS duration , CRT device type , New York Heart Association ( NYHA ) class , and LV reverse remodelling ( adjusted HR : 0.48 , P = 0.0086 ) . At one year , the symptomatic response rate ( improvement by ≥ 1 NYHA classes or ≥ 25 % increase in walking distance ) was 78 % for both women and men . CONCLUSIONS Female gender is independently associated with a lower mortality and morbidity after CRT Background — Cardiac resynchronization therapy ( CRT ) is an effective therapy for patients with moderate to severe heart failure and prolonged QRS duration . The purpose of this study was to determine whether reverse left ventricular ( LV ) remodeling and symptomatic benefit from CRT were sustained at 12 months , and if so , in what proportion of patients this occurred . Methods and Results — Serial Doppler echocardiograms were obtained at baseline and 6 and 12 months after CRT in 228 patients enrolled in the Multicenter InSync R and omized Clinical Evaluation ( MIRACLE ) trial . Measurements were made of LV end-diastolic ( EDV ) and end-systolic ( ESV ) volumes , ejection fraction , LV mass , severity of mitral regurgitation ( MR ) , peak transmitral velocities during early ( E wave ) and late ( A wave ) diastolic filling , and myocardial performance index . At both 6 and 12 months , respectively , CRT was associated with reduced LV EDV ( P<0.0001 and P=0.007 ) and LV ESV ( P<0.0001 and P<0.0001 ) , improved ejection fraction ( P<0.0001 and P<0.0001 ) , regression of LV mass ( P=0.012 and P<0.0001 ) , and reduced MR ( P<0.0001 and P<0.0001 ) . LV filling time , transmitral E/A ratio , and myocardial performance index all improved at 12 months compared with baseline ( P<0.001 , P=0.031 , and P<0.0001 ) . Reverse LV remodeling with CRT occurred in more patients at 6 than at 12 months ( 74 % versus 60 % , respectively ; P<0.05 ) and was greater in patients with a nonischemic than an ischemic etiology . Conclusions — Reverse LV remodeling and symptom benefit with CRT are sustained at 12 months in patients with New York Heart Association class III/IV heart failure but occur to a lesser degree in patients with an ischemic versus a nonischemic etiology , most likely owing to the inexorable progression of ischemic disease OBJECTIVES We sought to investigate the impact of six months of cardiac resynchronization therapy ( CRT ) on echocardiographic variables of left ventricular ( LV ) function . BACKGROUND Cardiac resynchronization therapy has recently been introduced as a new therapeutic modality in patients with advanced heart failure ( HF ) and conduction abnormalities . However , most studies have only investigated the early hemodynamic effects of CRT . METHODS Twenty-five patients ( 12 women and 13 men ; 59.8 + /- 5.1 years old ) with advanced HF caused by ischemic ( n = 7 ) or idiopathic dilated cardiomyopathy ( n = 18 ) and a prolonged QRS complex were analyzed . All patients underwent early hemodynamic testing with a r and omized testing protocol ; echocardiographic measurements were compared before implantation and after six months of CRT . RESULTS Left ventricular end-diastolic and end-systolic diameters ( LVEDD and LVESD , respectively ) were significantly reduced after six months ( LVEDD from 71 + /- 10 to 68 + /- 11 mm , p = 0.027 ; LVESD from 63 + /- 11 to 58 + /- 11 mm , p = 0.007 ) , as were LV end-diastolic and end-systolic volumes ( LVEDV from 253 + /- 83 to 227 + /- 112 ml , p = 0.017 ; LVESV from 202 + /- 79 to 174 + /- 101 ml , p = 0.009 ) . Ejection fraction was significantly increased ( from 22 + /- 7 % to 26 + /- 9 % , p = 0.03 ) . " Nonresponders , " with regard to LV volume reduction , had significantly higher baseline LVEDV , compared with " responders " ( 351 + /- 52 vs. 234 + /- 74 ml , p = 0.018 ) . Overall , there was only mild mitral regurgitation at baseline , with a minor reduction by semiquantitative analysis . The results of early hemodynamic testing did not predict the volume response . CONCLUSIONS Cardiac resynchronization therapy may lead to a reduction in LV volumes in patients with advanced HF and conduction disturbances . Volume nonresponders have significantly higher baseline LVEDV AIM Gender related differences in epidemiology , treatment , and prognosis of heart failure ( HF ) have been reported . We examined the sex influence in patients treated with cardiac resynchronization therapy ( CRT ) .  METHODS AND RESULTS Out of 334 consecutive HF patients ( 19.7 % women ) who underwent CRT , 195 patients reached clinical and echocardiographic evaluation at six and 12 months and were selected for analysis . A reduction in left ventricular ( LV ) end-diastolic volume/m(2 ) ( EDVi ) and end systolic volume/m(2 ) ( ESVi ) was evident in the overall population at six months ( P < 0.001 ) and from six to 12 months ( P < 0.001 ) . Compared to men , women showed significantly greater changes in LV volumes at mid ( P < 0.05 ) and long-term ( P < 0.001 ) follow-up and a significantly higher LV ejection fraction ( EF ) ( 40.8 + /- 12.3 vs 34.1 + /- 10.1 , P < 0.01 ) at one year . Multiple regression analysis , including several demographic and clinical parameters , revealed that female gender is independently associated with greater reduction in LV ESVi . At the 12-month follow-up , the proportion of responders ( defined in terms of ESV reduction by at least 10 % ) was higher in women than in men ( 76.1 % vs 59.3 % , P < 0.05 ) . CONCLUSIONS CRT induced a gender specific LV remodeling response OBJECTIVES The purpose of this study was to investigate the factors related to sex-specific outcomes for death and heart failure events in the MADIT-CRT ( Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy ) trial . BACKGROUND In the MADIT-CRT trial , women seemed to achieve a better result from resynchronization therapy than men . METHODS All 1,820 patients ( 453 female and 1,367 male ) enrolled in the MADIT-CRT trial were included in this sex-specific outcome analysis that compared the effect of cardiac resynchronization therapy with defibrillator ( CRT-D ) relative to implanted cardioverter-defibrillator ( ICD ) on death or heart failure ( whichever came first ) , heart failure only , and death at any time . RESULTS Female patients were more likely to have nonischemic cardiomyopathy and left bundle branch block and less likely to have renal dysfunction than male patients . Overall , female patients had a better result from CRT-D therapy than male patients , with a significant 69 % reduction in death or heart failure ( hazard ratio : 0.31 , p < 0.001 ) and 70 % reduction in heart failure alone ( hazard ratio : 0.30 , p < 0.001 ) . Women had a significant 72 % reduction in all-cause mortality in the total population ( hazard ratio : 0.28 , p = 0.02 ) and significant 82 % and 78 % reductions in mortality in those with QRS ≥ 150 ms and with left bundle branch block conduction disturbance , respectively , with sex-by-treatment interactions for mortality reduction significant at p < 0.05 in each of these 3 patient groups . These beneficial CRT-D effects among women were associated with consistently greater echocardiographic evidence of reverse cardiac remodeling in women than in men . CONCLUSIONS Women in the MADIT-CRT trial obtained significantly greater reductions in death or heart failure ( whichever came first ) , heart failure alone , and all-cause mortality  with CRT-D therapy than men , with consistently greater echocardiographic evidence of reverse cardiac remodeling in women than in men . ( Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy [ MADIT-CRT ] ; NCT00180271 ) 
    Output:
    
Women seem to obtain greater benefits from CRT both in clinical and echocardiographic outcomes compared with men .