***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 Ischemic mitral regurgitation is associated with a substantial risk of death . Practice guidelines recommend surgery for patients with a severe form of this condition but acknowledge that the supporting evidence for repair or replacement is limited . METHODS We r and omly assigned 251 patients with severe ischemic mitral regurgitation to undergo either mitral-valve repair or chordal-sparing replacement in order to evaluate efficacy and safety . The primary end point was the left ventricular end-systolic volume index ( LVESVI ) at 12 months , as assessed with the use of a Wilcoxon rank-sum test in which deaths were categorized below the lowest LVESVI rank . RESULTS At 12 months , the mean LVESVI among surviving patients was 54.6±25.0 ml per square meter of body-surface area in the repair group and 60.7±31.5 ml per square meter in the replacement group ( mean change from baseline , -6.6 and -6.8 ml per square meter , respectively ) . The rate of death was 14.3 % in the repair group and 17.6 % in the replacement group ( hazard ratio with repair , 0.79 ; 95 % confidence interval , 0.42 to 1.47 ; P=0.45 by the log-rank test ) . There was no significant between-group difference in LVESVI after adjustment for death ( z score , 1.33 ; P=0.18 ) . The rate of moderate or severe recurrence of mitral regurgitation at 12 months was higher in the repair group than in the replacement group ( 32.6 % vs. 2.3 % , P<0.001 ) . There were no significant between-group differences in the rate of a composite of major adverse cardiac or cerebrovascular events , in functional status , or in quality of life at 12 months . CONCLUSIONS We observed no significant difference in left ventricular reverse remodeling or survival at 12 months between patients who underwent mitral-valve repair  and those who underwent mitral-valve replacement . Replacement provided a more durable correction of mitral regurgitation , but there was no significant between-group difference in clinical outcomes . ( Funded by the National Institutes of Health and the Canadian Institutes of Health ; Clinical Trials.gov number , NCT00807040 . ) Background — When compared to mitral valve replacement ( MVR ) , mitral valve repair ( MVRp ) is associated with better survival in patients with organic mitral regurgitation ( MR ) . However , there is an important controversy about the type of surgical treatment that should be used in patients with ischemic MR . The objective of this study was to compare the postoperative outcome of MVRp versus MVR in patients with ischemic MR . Methods and Results — Preoperative and operative data of 370 patients with ischemic MR who underwent mitral valve surgery  were prospect ively collected and retrospectively analyzed . MVRp was performed in 50 % of patients ( n=186 ) and MVR in 50 % ( n=184 ) . Although operative mortality was significantly lower after MVRp compared to MVR ( 9.7 % versus 17.4 % ; P=0.03 ) , overall 6-year survival was not statistically different between procedures ( 73±4 % versus 67±4 % ; P=0.17 ) . After adjusting for other risk factors and propensity score , the type of procedure  ( MVRp versus MVR ) did not come out as an independent predictor of either operative ( OR , 1.5 ; 95 % CI , 0.7–2.9 ; P=0.34 ) or overall mortality ( HR , 1.2 ; 95 % CI , 0.7–1.9 ; P=0.52 ) . Conclusion — As opposed to what has been reported in patients with organic MR , the results of this study suggest that MVRp is not superior to MVR with regard to operative and overall mortality in patients with ischemic MR . These findings provide support for the realization of a r and omized trial comparing these 2 treatment modalities BACKGROUND Mitral regurgitation ( MR ) may complicate acute myocardial infa rct ion ( MI ) . However , it is not known whether mild MR is an independent predictor of post-MI outcome . METHODS AND RESULTS The study cohort consisted of 727 Survival and Ventricular Enlargement Study patients who underwent cardiac catheterization , including left ventriculography , up to 16 days after MI . Left ventriculograms were analyzed for diastolic and systolic volumes , global left ventricular sphericity , extent of wall motion abnormality , and endocardial curvature . The presence of MR was related to the risk of developing a cardiovascular event during 3.5 years of follow-up . MR was present in 141 patients ( 19.4 % ) .  Severe ( 3 + ) MR was present in only 2 patients . Patients with MR were more likely to have a persistently occluded infa rct artery ( MR versus no MR , 27.3 % versus 15.2 % ; P=.001 ) . Although the ejection fractions were similar , MR patients had larger end-systolic and end-diastolic volumes and more spherical ventricles than patients without MR . Sphericity change from diastole to systole was also significantly reduced in MR patients . Patients with MR were more likely to experience cardiovascular mortality ( 29 % versus 12 % ; P<.001 ) , severe heart failure ( 24 % versus 16 % ; P=.0153 ) , and the combined end point of cardiovascular mortality , severe heart failure , or recurrent myocardial infa rct ion ( 47 % versus 29 % ; P<.001 ) . The presence of MR was an independent predictor of cardiovascular mortality ( relative risk , 2.00 ; 95 % CI , 1.28 to 3.04 ) . CONCLUSIONS Mild MR is an independent predictor of post-MI mortality . As such , it adds important information for risk stratification of post-MI patients OBJECTIVES Mitral valve ( MV ) surgery for ischaemic mitral regurgitation ( IMR ) in patients with depressed left ventricular ejection fraction ( LVEF ) is associated with poor outcomes . The optimal surgical strategy for IMR in these patients remains controversial . The objective of this study was to compare the early mortality and mid-term survival of MV repair versus MV replacement in patients with IMR and depressed LVEF undergoing coronary artery bypass grafting ( CABG ) .  METHODS A retrospective , observational , cohort study was undertaken of prospect ively collected data on 126 consecutive CABG patients with IMR and LVEF < 40 % undergoing either MV repair ( n = 98 , 78 % ) or MV replacement ( n = 28 , 22 % ) between July 2002 and February 2011 . RESULTS The overall mortality rate was 7.9 % ( n = 10 ) . MV replacement was associated with a 4-fold increase in the risk of death compared with MV repair [ 17.9 % , n = 5 vs 5.1 % , n = 5 ; odds ratio ( OR ) 4.04 , 95 % confidence interval ( CI ) 1.08 - 15.1 , P = 0.04 ] . However , after adjusting for preoperative risk factors , the type of surgical procedure was not an independent risk factor for early mortality ( OR 0.1 , 95 % CI 0.01 - 31 , P = 0.7 ) . Multivariable analysis showed that preoperative LVEF ( OR 0.8 , 95 % CI 0.6 - 0.9 , P = 0.018 ) , preoperative B-type natriuretic peptide ( BNP ) levels ( OR 1.01 , 95 % CI 1 - 1.02 , P = 0.025 ) , preoperative left ventricle end-systolic diameter ( OR 0.8 , 95 % CI 0.7 - 1.0 , P = 0.05 ) and preoperative left atrial diameter ( OR 1.3 , 95 % CI 1.0 - 1.6 , P = 0.015 ) were independent risk factors of early mortality . At the median follow-up of 45 months ( interquartile range 20 - 68 months ) , the mid-term survival rate was 74 % in the MV repair group and 70 % in the MV replacement group ( P = 0.08 ) . At follow-up , predictors of worse survival were BNP levels [ hazard ratio ( HR ) 1.0 , 95 % CI 1.0 - 1.01 , P = 0.047 ] , preoperative renal failure ( HR 4.6 , 95 % CI 1.1 - 20.3 , P = 0.039 ) and preoperative atrial fibrillation ( HR 3.3 , 95 % CI 1.1 - 10 , P = 0.032 ) . CONCLUSIONS MV repair in CABG patients with IMR and depressed LVEF is not superior to MV replacement with regard to operative early mortality and mid-term survival OBJECTIVE Mitral incompetence is a chronic sequela of myocardial infa rct ion . It is caused by apical displacement and tethering of the mitral valve leaflets after myocardial infa rct ion , result ing in incomplete coaptation . The consensus is for mitral valve surgery in the presence of significant ischemic mitral regurgitation ( IMR ) . Previously , the only option was mitral valve replacement ( MVR ) with a mechanical or tissue valve . The suboptimal results obtained prompted the development of several methods of mitral valve repair . Today , the most commonly used repair is undersized annuloplasty . METHODS We conducted a retrospective nonr and omized study of all patients who underwent operation for coronary artery disease and IMR between 2000 and 2006 . The surgeon chose the surgical method used for the mitral valve procedure . The most commonly used procedures were restrictive mitral valve annuloplasty ( MVP ) and MVR with a mechanical prosthesis . We collected all pertinent preoperative , intraoperative , and early-postoperative data . We followed up with phone interviews of the patients and their relatives and with complete clinical and echocardiography examinations . RESULTS We carried out operations on 138 patients during the study period ( MVR , 52 patients ; MVP , 86 patients ) . The 2 groups had comparable demographic data and risk factors . The 2 groups were significantly different with respect to mean ( + /-SD ) New York Heart Association ( NYHA ) class ( MVP , 2.72 + /- 0.62 ; MVR , 2.48 + /- 0.70 ; P < .01 ) and ejection fraction ( MVP , 29.01 % + /- 11.00 % ; MVR , 35.87 % + /- 11.00 % ; P < /= .01 ) . The 30-day mortality rates for the MVR and MVP groups were significantly different ( 9.61 % and 5.81 % , respectively ; P < .01 ) . Our follow-up included 83 % of the patients and continued for up to 84 months . The 2 groups showed no significant difference in mortality by the end of follow-up ; however , the MVR patients had a better ejection fraction ( 37.79 % versus 29.86 % ) and NYHA functional class ( 1.88 + /- 0.498 versus 2.36 + /- 0.564 ; P < .01 ) . CONCLUSION Correcting chronic IMR with either repair or replacement produces a good mid-term survival rate ( approximately 75 % ) for survivors in NYHA classes I and II . In our study , mortality rates for the MVP and MVR groups were similar , even though the repair group had a lower mean ejection fraction and a higher NYHA class before and after the operation . We therefore conclude that repair is superior to replacement in treating ischemic mitral insufficiency . A prospect i ve r and omized study is needed to better compare these 2 approaches 
    Output:
    
Although MVR for ischaemic MR has a higher 30-day mortality rate compared with MVRp , MVRp is associated with the higher rate of MR recurrence and the need for reoperation .
MVR remains an attractive option for ischaemic MR