***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: OBJECTIVES Redo cardiac surgery has an increased risk of morbidity and mortality when compared with the initial operation . The aim of this study was to assess the impact of previous cardiac operations on patients undergoing transapical aortic valve implantation ( TA-TAVI ) .  METHODS We analysed data from 566 patients included in the Italian Registry of Transapical Aortic Valve Implantation who underwent TA-TAVI implantation with the Sapien valve ( Edwards Lifesciences , Irvine , CA , USA ) from April 2008 through May 2011 . Of these , 110 patients ( 19.4 % ) had already undergone at least one previous cardiac operation with opening of the pericardium ( group R ) while for 456 patients ( 80.6 % ) TA-TAVI was the first cardiac procedure ( group F ) . Data were prospect ively collected at each of the 20 participating centres and then sent to a central data base for storage and analysis . RESULTS Preoperative logistic EuroSCORE was higher in group R ( 35 ± 18.6 vs. 23.5 ± 11.9 % ; P < 0.001 ) . Hospital mortality occurred in eight ( 7.2 % ) and 36 ( 7.9 % ) patients in groups R and F , respectively ( P = 0.8 ) . Mean follow-up was 10.4 ± 7.9 months ( range : 1 - 34 ) . Overall 2-year Kaplan-Meier survival was 64.2 ± 9.8 and 75.4 ± 3.5 % in groups R and F , respectively ( P = 0.69 ) . Incidence of operative complications , postoperative bleeding , pacemaker implantation , myocardial infa rct ion and stroke did not show statistically significant differences between groups . The univariate analysis showed that arterial hypertension , logistic EuroSCORE , porcelain aorta , left ventricular ejection fraction and previous percutaneous coronary interventions were significantly associated with 30-day mortality in group R. CONCLUSIONS According to our data , patients undergoing TAVI with previous cardiac operations have a higher preoperative risk profile but have similar outcomes when compared with patients undergoing a first operation . In these subset of patients , TAVI is a promising therapeutic option We report a prospect i ve comparison between  transcatheter valve implantation ( TAVI , n = 13 ) and surgical aortic valve replacement ( AVR , n = 10 ) in patients with severe aortic valve stenosis and previous coronary bypass surgery ( CABG ) . All patients had at least bilateral patent internal thoracic arteries bypass without indication of repeat revascularization . After a similar post-procedure outcome , despite one early death in TAVI group , the 1-year survival was 100 % in surgical group and in transfemoral TAVI group , and 73 % in transapical TAVI group . When previous CABG is the lone surgical risk factor , indications for a TAVI procedure have to be cautious , specially if transfemoral approach is not possible OBJECTIVES Surgical aortic valve replacement in patients with previous coronary artery bypass grafting ( CABG ) carries a high mortality . Transcatheter aortic valve implantation ( TAVI ) has been shown to be successful in high risk subgroups of patients . Our goal is therefore to evaluate the impact of a history of CABG on the outcome of patients who undergo TAVI .  METHODS From October 2006 to June 2010 , among the 201 patients selected to undergo TAVI , 54 ( 27 % ) had a history of CABG .  Outcomes were prospect ively collected . RESULTS The 30-day outcome was not different between patients with previous CABG vs. those without , in particular as regards mortality ( respectively , 5.6 % vs. 10.9 % ; P = 0.25 ) . Mid-term survival ( mean FU : 7 ± 9 months ) was not different at 2 years between patients with previous CABG vs. patients without ( 65.7 ± 6.2 % vs. 80.0 ± 7.7 % respectively ; P = 0.12 ) . In multivariate analysis , CABG was not associated with an excess mid-term mortality  after TAVI . CONCLUSIONS Previous CABG does not adversely affect outcome in patients  undergoing TAVI . If confirmed by larger prospect i ve series and ideally by a r and omized trial comparing CABG vs. redo surgery , this observation might lead the heart team to consider TAVI as an attractive option in the population of high risk patients with aortic stenosis and previous CABG OBJECTIVES The logistic European System for Cardiac Operative Risk Evaluation ( LES ) score and the Society of Thoracic Surgeons ( STS ) score are vali date d to predict 30-day outcomes following surgical aortic valve replacement ( SAVR ) with or without coronary artery bypass grafting . Their performance when applied to patients undergoing transcatheter aortic valve replacement ( TAVR )  is controversial . METHODS We compared predicted and observed 30-day/in-hospital and 1-year mortality of patients undergoing TAVR in the first Placement of Aortic Transcatheter Valves trial and continued access registry ( N = 2466 ) . The performance of the LES and STS scores  ( prospect ively calculated ) was evaluated using st and ard assessment s of discrimination and calibration . Performance of STS and LES scores among 307 patients undergoing SAVR from the high-risk cohort of the r and omized trial were also examined . RESULTS In patients undergoing TAVR , the observed 30-day/in-hospital mortality was 6.5 % , whereas the predicted 30-day mortality was higher by both STS score ( 11.4 % ± 3.9 % ) and LES score ( 26.6 % ± 16.2 % ) . The discrimination for both scores was poor for 30-day/in-hospital and 1-year mortality . Calibration was better for STS score than for LES at 1 year but poor for both at 30 days among TAVR cohort . These results were consistent among the subgroups of patients undergoing transfemoral and transapical access ; however , the STS score had better performance among the high-risk patients who underwent SAVR at 30 days but not 1 year . CONCLUSIONS The STS and LES surgical risk scores overestimated 30-day/in-hospital mortality and were poor discriminators of post-TAVR mortality , but the calibration of the STS score was better in these high-risk patients . These data highlight the need for TAVR-specific risk models to optimize patient selection OBJECTIVES The aim of this study was : 1 ) to evaluate the acute and late outcomes of a transcatheter aortic valve implantation ( TAVI ) program including both the transfemoral ( TF ) and transapical ( TA ) approaches ; and 2 ) to determine the results of TAVI  in patients deemed inoperable because of either porcelain aorta or frailty . BACKGROUND Very few data exist on the results of a comprehensive TAVI program including both TA and TF approaches for the treatment of severe aortic stenosis in patients at very high or prohibitive surgical risk . METHODS Consecutive patients who underwent TAVI with the Edwards valve ( Edwards Lifesciences , Inc. , Irvine , California ) between January 2005 and June 2009 in 6 Canadian centers were included . RESULTS A total of 345 procedures ( TF : 168 , TA : 177 ) were performed in 339 patients . The predicted surgical mortality ( Society of Thoracic Surgeons risk score ) was 9.8 + /- 6.4 % . The procedural success rate was 93.3 % , and 30-day mortality was 10.4 % ( TF : 9.5 % , TA : 11.3 % ) . After a median follow-up of 8 months ( 25th to 75th interquartile range : 3 to 14 months ) the mortality rate was 22.1 % . The predictors of cumulative late mortality were peri-procedural sepsis ( hazard ratio [ HR ] : 3.49 , 95 % confidence interval [ CI ] : 1.48 to 8.28 ) or need for hemodynamic support ( HR : 2.58 , 95 % CI : 1.11 to 6 ) , pulmonary hypertension ( PH ) ( HR : 1.88 , 95 % CI : 1.17 to 3 ) , chronic kidney disease ( CKD ) ( HR : 2.30 , 95 % CI : 1.38 to 3.84 ) , and chronic obstructive pulmonary disease ( COPD ) ( HR : 1.75 , 95 % CI : 1.09 to 2.83 ) . Patients with either porcelain aorta ( 18 % ) or frailty ( 25 % ) exhibited acute outcomes similar to the rest of the study population , and porcelain aorta patients tended to have a better survival rate at 1-year follow-up . CONCLUSIONS A TAVI program including both TF and TA approaches was associated with comparable mortality as predicted by surgical risk calculators for the treatment of patients at very high or prohibitive surgical risk , including porcelain aorta and frail patients . Baseline ( PH , COPD , CKD ) and peri-procedural ( hemodynamic support , sepsis ) factors but not the approach determined worse outcomes Previous coronary artery bypass grafting ( CABG ) increases operative risk in conventional valve replacement . Transcatheter aortic valve implantation ( TAVI ) has been shown to be successful in high-risk patient subgroups . The present study compared outcome and overall survival in patients who underwent TAVI with and without history of CABG . From January 2010 to December 2011 , 683 of the 3,761 patients selected for TAVI in 34 French centers ( 18 % ) had a history of CABG .  Outcomes ( mortality and complications ) were collected prospect ively according to the Valve Academic Research Consortium ( VARC ) criteria . Patients with previous CABG  were younger , with higher rates of diabetes and vascular disease and higher logistic European System for Cardiac Operative Risk Evaluation ( 29.8 ± 16.4 vs 20.1 ± 13.0 , p < 0.001 ) but lower rates of pulmonary disease . Two types of valve ( Edwards SAPIEN and Medtronic CoreValve ) were implanted in equal proportions in the 2 groups . The 30-day and 1-year mortality rates from all causes on Kaplan-Meier analysis ( 9.2 % vs 9.7 % , p = 0.71 ; and 19.0 % vs 20.2 % , p = 0.49 , respectively ) did not differ according to the history of CABG . There were no significant differences in the Valve Academic Research Consortium complications ( myocardial infa rct ion , stroke or vascular , and bleeding complications ) . On multivariate analysis , CABG was not associated with greater 1-year post-TAVI mortality . In conclusion , previous CABG did not adversely affect outcome in patients who underwent TAVI  , which may be an alternative to surgery in high-risk patients with severe aortic stenosis and history of CABG BACKGROUND Many patients with severe aortic stenosis and coexisting conditions are not c and i date s for surgical replacement of the aortic valve . Recently , transcatheter aortic-valve implantation ( TAVI ) has been suggested as a less invasive treatment for high-risk patients with aortic stenosis . METHODS We r and omly assigned patients with severe aortic stenosis , whom surgeons considered not to be suitable c and i date s for surgery , to st and ard therapy ( including balloon aortic valvuloplasty ) or transfemoral transcatheter implantation of a balloon-exp and able bovine pericardial valve .  The primary end point was the rate of death from any cause . RESULTS A total of 358 patients with aortic stenosis who were not considered to be suitable c and i date s for surgery underwent r and omization at 21 centers ( 17 in the United States ) . At 1 year , the rate of death from any cause ( Kaplan – Meier analysis ) was 30.7 % with TAVI , as compared with 50.7 % with st and ard therapy ( hazard ratio with TAVI , 0.55 ; 95 % confidence interval [ CI ] , 0.40 to 0.74 ; P<0.001 ) . The rate of the composite end point of death from any cause or repeat hospitalization was 42.5 % with TAVI as compared with 71.6 % with st and ard therapy ( hazard ratio , 0.46 ; 95 % CI , 0.35 to 0.59 ; P<0.001 ) . Among survivors at 1 year , the rate of cardiac symptoms ( New York Heart Association class III or IV ) was lower among patients who had undergone TAVI than among those who had received st and ard therapy ( 25.2 % vs. 58.0 % , P<0.001 ) . At 30 days , TAVI , as compared with st and ard therapy , was associated with a higher incidence of major strokes ( 5.0 
    Output:
    
Conclusions : Previous CABG is not associated with either all-cause mortality or CV mortality in patients with severe AS undergoing TAVR .