***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: AIMS Transcatheter aortic valve implantation ( TAVI ) has gained rapid acceptance for patients with severe aortic stenosis ( AS ) at high surgical risk for conventional valve replacement . Although TAVI is now a relatively mature technique , limited data about long-term valvular function are available . Our aim was to report the five-year echocardiographic data evaluating valve performance from three early European feasibility studies design ed to assess the safety and effectiveness of the first-generation balloon-exp and able transcatheter heart valve ( SAPIEN THV ) . METHODS AND RESULTS A total of 410 patients were enrolled in the following single-arm , non-r and omised , prospect i ve multicentre clinical studies : REVIVE II , TRAVERCE and PARTNER EU . Five-year follow-up was completed in 114 surviving patients . Mean patient age was 82.3±5.6 years ; 63.4 % were female . The mean logistic EuroSCORE was 28.4±13.3 % .  NYHA Class III/IV was reported in 92.5 % . At five years , the mean effective orifice area ( EOA ) was 1.6±0.6 cm² ( n=34 ) and the mean gradient was 11.7±5.4 mmHg ( n=39 ) . In paired patient data , the difference between discharge and five-year EOA was 0.1±0.7 cm² ( p=0.3956 ) and mean gradient was 2.2±5.7 mmHg ( p=0.0900 ) . At discharge and five years , respectively , aortic regurgitation ( AR ) was evaluated as none/trace in 66.6 % ( n=162/243 ) and 55.3 % ( n=19/38 ) , mild in 28.4 % ( n=69/243 ) and 39.5 % ( n=15/38 ) , and moderate in 4.9 % ( n=12/243 ) and 5.3 % ( n=2/38 ) . No severe AR was reported at follow-up . Valve thrombosis was observed in three patients and occurred within one year . No valve-related explants and no case of structural valve deterioration have been reported . CONCLUSIONS Long-term echocardiographic outcomes in high-risk patients with severe AS suggest stable haemodynamic function of first-generation balloon-exp and able SAPIEN THVs at five years , with no worsening of AR severity over time BACKGROUND Little is known about the incidence of prosthesis-patient mismatch ( PPM ) and its impact on outcomes after transcatheter aortic valve replacement ( TAVR ) . OBJECTIVES The objectives of this study were : 1 ) to compare the incidence of PPM in the TAVR and surgical aortic valve replacement ( SAVR ) r and omized control trial ( RCT ) arms of the PARTNER ( Placement of AoRTic TraNscathetER Valves ) I Trial cohort A ; and 2 ) to assess the impact of PPM on regression of left ventricular ( LV ) hypertrophy and mortality in these 2 arms and in the TAVR nonr and omized continued access ( NRCA ) registry cohort . METHODS The PARTNER Trial cohort A r and omized patients 1:1 to TAVR or bioprosthetic SAVR .  Postoperative PPM was defined as absent if the indexed effective orifice area ( EOA ) was > 0.85 cm(2)/m(2 ) , moderate if the indexed EOA was ≥0.65 but ≤0.85 cm(2)/m(2 ) , or severe if the indexed EOA was < 0.65 cm(2)/m(2 ) . LV mass regression and mortality were analyzed using the SAVR- RCT ( n = 270 ) , TAVR- RCT ( n = 304 ) , and TAVR-NRCA ( n = 1,637 ) cohorts . RESULTS The incidence of PPM was 60.0 % ( severe : 28.1 % ) in the SAVR- RCT cohort versus 46.4 % ( severe : 19.7 % ) in the TAVR- RCT cohort ( p < 0.001 ) and 43.8 % ( severe : 13.6 % ) in the TAVR-NRCA cohort . In patients with an aortic annulus diameter < 20 mm , severe PPM developed in 33.7 % undergoing SAVR compared with 19.0 % undergoing TAVR ( p = 0.002 ) . PPM was an independent predictor of less LV mass regression at 1 year in the SAVR- RCT ( p = 0.017 ) and TAVR-NRCA ( p = 0.012 ) cohorts but not in the TAVR- RCT cohort ( p = 0.35 ) . Severe PPM was an independent predictor of 2-year mortality in the SAVR- RCT cohort ( hazard ratio [ HR ] : 1.78 ; p = 0.041 ) but not in the TAVR- RCT cohort ( HR : 0.58 ; p = 0.11 ) . In the TAVR-NRCA cohort , severe PPM was not a predictor of 1-year mortality in all patients ( HR : 1.05 ; p = 0.60 ) but did independently predict mortality in the subset of patients with no post-procedural aortic regurgitation ( HR : 1.88 ; p = 0.02 ) . CONCLUSIONS In patients with severe aortic stenosis and high surgical risk , PPM is more frequent and more often severe after SAVR than TAVR . Patients with PPM after SAVR have worse survival and less LV mass regression than those without PPM . Severe PPM also has a significant impact on survival after TAVR in the subset of patients with no post-procedural aortic regurgitation . TAVR may be preferable to SAVR in patients with a small aortic annulus who are susceptible to PPM to avoid its adverse impact on LV mass regression and survival . ( The PARTNER Trial : Placement of AoRTic TraNscathetER Valve Trial ; NCT00530894 ) Objective To determine the frequency of survival , stroke , atrial fibrillation , structural valve deterioration , and length of hospital stay after surgical replacement of an aortic valve ( SAVR ) with a bioprosthetic valve in patients with severe symptomatic aortic stenosis . Design Systematic review and meta- analysis of observational studies . Data sources Medline , Embase , PubMed ( non- Medline records only ) , Cochrane Data base of Systematic Review s , and Cochrane CENTRAL from 2002 to June 2016 . Study selection Eligible observational studies followed patients after SAVR with a bioprosthetic valve for at least two years . Methods Review ers , independently and in duplicate , evaluated study eligibility , extracted data , and assessed risk of bias for patient important outcomes . We used the GRADE system to quantify absolute effects and quality of evidence . Published survival curves provided data for survival and freedom from structural valve deterioration , and r and om effect models provided the framework for estimates of pooled incidence rates of stroke , atrial fibrillation , and length of hospital stay . Results In patients undergoing SAVR with a bioprosthetic valve , median survival was 16 years in those aged 65 or less , 12 years in those aged 65 to 75 , seven years in those aged 75 to 85 , and six years in those aged more than 85 . The incidence rate of stroke was 0.25 per 100 patient years ( 95 % confidence interval 0.06 to 0.54 ) and atrial fibrillation 2.90 per 100 patient years ( 1.78 to 4.79 ) . Post-SAVR , freedom from structural valve deterioration was 94.0 % at 10 years , 81.7 % at 15 years , and 52 % at 20 years , and mean length of hospital stay was 12 days ( 95 % confidence interval 9 to 15 ) . Conclusion Patients with severe symptomatic aortic stenosis undergoing SAVR  with a bioprosthetic valve can expect only slightly lower survival than those without aortic stenosis , and a low incidence of stroke and , up to 10 years , of structural valve deterioration . The rate of deterioration increases rapidly after 10 years , and particularly after 15 years BACKGROUND In patients with severe aortic stenosis at increased risk for surgery , self-exp and ing transcatheter aortic valve replacement ( TAVR ) is associated with improved 2-year survival compared with surgery . OBJECTIVES This study sought to determine whether this clinical benefit was sustained over time . METHODS Patients with severe aortic stenosis deemed at increased risk for surgery by a multidisciplinary heart team were r and omized 1:1 to TAVR or open surgical valve replacement ( SAVR ) .  Three-year clinical and echocardiographic outcomes were obtained in those patients with an attempted procedure . RESULTS A total of 797 patients underwent r and omization at 45 U.S. centers ; 750 patients underwent an attempted procedure . Three-year all-cause mortality or stroke was significantly lower in TAVR patients ( 37.3 % vs. 46.7 % in SAVR ; p = 0.006 ) . Adverse clinical outcome components were also reduced in TAVR patients compared with SAVR patients , including all-cause mortality ( 32.9 % vs. 39.1 % , respectively ; p = 0.068 ) , all stroke ( 12.6 % vs. 19.0 % , respectively ; p = 0.034 ) , and major adverse cardiovascular or cerebrovascular events ( 40.2 % vs. 47.9 % , respectively ; p = 0.025 ) . At 3 years aortic valve hemodynamics were better with TAVR patients ( mean aortic valve gradient 7.62 ± 3.57 mm Hg vs. 11.40 ± 6.81 mm Hg in SAVR ; p < 0.001 ) , although moderate or severe residual aortic regurgitation was higher in TAVR patients ( 6.8 % vs. 0.0 % in SAVR ; p < 0.001 ) . There was no clinical evidence of valve thrombosis in either group . CONCLUSIONS Patients with severe aortic stenosis at increased risk for surgery had improved 3-year clinical outcomes  after TAVR compared with surgery . Aortic valve hemodynamics were more favorable in TAVR patients without differences in structural valve deterioration . ( Safety and Efficacy Study of the Medtronic CoreValve ( ® ) System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement ; NCT01240902 ) BACKGROUND Scarce data exist on the incidence of and factors associated with valve hemodynamic deterioration ( VHD )  after transcatheter aortic valve replacement ( TAVR ) .  OBJECTIVES This study sought to determine the incidence , timing , and predictors of VHD in a large cohort of patients undergoing TAVR .  METHODS This multicenter registry included 1,521 patients ( 48 % male ; 80 ± 7 years of age ) who underwent TAVR .  Mean echocardiographic follow-up was 20 ± 13 months ( minimum : 6 months ) .  Echocardiographic examinations  were performed at discharge , at 6 to 12 months , and yearly thereafter . Annualized changes in mean gradient ( mm Hg/year ) were calculated by dividing the difference between the mean gradient at last follow-up and the gradient at discharge by the time between examinations . VHD was defined as a ≥10 mm Hg increase in transprosthetic mean gradient during follow-up compared with discharge assessment . RESULTS The overall mean annualized rate of transprosthetic gradient progression during follow-up was 0.30 ± 4.99 mm Hg/year . A total of 68 patients met criteria of VHD ( incidence : 4.5 % during follow-up ) . The absence of anticoagulation therapy  at hospital discharge ( p = 0.002 ) , a valve-in-valve ( TAVR in a surgical valve ) procedure ( p = 0.032 ) , the use of a 23-mm valve ( p = 0.016 ) , and a greater body mass index ( p = 0.001 ) were independent predictors of VHD . CONCLUSIONS There was a mild but significant increase in transvalvular gradients over time after TAVR . The lack of anticoagulation therapy , a valve-in-valve procedure , a greater body mass index , and the use of a 23-mm transcatheter valve were associated with higher rates of VHD post-TAVR . Further prospect i ve studies are required to determine whether a specific antithrombotic therapy post-TAVR may reduce the risk of VHD 
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Importantly , the freedom from reoperation for valve dysfunction at 10 , 15 and 20 years was 94 % , 81.7 % and 52 % , respectively.1 Figure 1 Structural valve deterioration .