You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Aortic valve stenosis after previous coronary bypass: Transcatheter valve implantation or aortic valve replacement?
Abstract 1:
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


Title 2:
Aortic valve replacement in patients with previous coronary artery bypass grafting: 10-year experience.
Abstract 2:
UNLABELLED OBJECTIVES ; This study aim ed to investigate the early and late outcomes of patients undergoing aortic valve replacement ( AVR ) with previous coronary artery bypass grafting ( CABG ) and patent grafts . METHODS Between January 2000 and March 2010 , 104 patients ( 87 males ) with previous CABG ± concomitant surgery and patent grafts underwent AVR . The median age of the patients was 75 years ( range : 37 - 90 years ; inter-quartile range : 69 - 79 years ) and the mean logistic EuroScore was 25.37 ± 16.8 .  The median time since the previous operation was 9 years ( range 1 - 25 ; inter-quartile range : 7 - 14 years ) . The left internal mammary artery ( LIMA ) had been used in 75 patients ( 72.1 % ) and remained patent in 72 cases ( 96.0 % ) . RESULTS Thirty-day mortality was 7.7 % ( n = 8) , which is less than the predicted mean logistic EuroScore . Isolated AVR was performed in 66 patients ( 63.5 % ) . The LIMA was dissected and isolated ( clamped or blocked with balloon ) in 60 patients . The median hospital stay was 10 days ( range : 4 - 183 days ; inter-quartile range : 7 - 15.25 days ) . Nineteen patients ( 18.3 % ) had pulmonary complications , while 12 ( 11.5 % ) had acute kidney injury . Seven patients ( 6.7 % ) required permanent pacemaker . Six LIMAs ( 8.3 % ) were injured and repaired . Prolonged aortic cross-clamp ( AXC ) time ( P = 0.038 ) and the presence of a previous LIMA graft ( P = 0.045 ) were identified as independent predictors of 30-day mortality . The actuarial survival at 1 and 5 years was 89.4 ± 0.3 and 81.5 ± 0.5 % , respectively . Perioperative intra-aortic balloon pump use ( P = 0.036 ) , prolonged AXC time ( P = 0.004 ) and prolonged cardiopulmonary bypass time ( P = 0.022 ) were associated with worse long-term overall survival on multivariate analysis . CONCLUSIONS AVR post-CABG with patent grafts can be performed in high-risk patients with excellent short- and long-term outcomes and appears to be superior to published catheter-based interventions . In the absence of r and omized trial data , we believe that open AVR remains the treatment of choice for aortic valve disease following prior CABG


Title 3:
5-Year Outcomes After Transcatheter Aortic Valve Implantation With CoreValve Prosthesis.
Abstract 3:
OBJECTIVES The purpose of this analysis was to assess 5-year outcomes of  transcatheter aortic valve implantation ( TAVI )  using the current technology of the self-exp and ing CoreValve prosthesis ( Medtronic Inc. , Minneapolis , Minnesota ) . BACKGROUND There is a paucity of evidence on long-term durability of currently available transcatheter heart valves . METHODS Starting in June 2007 , all consecutive patients with severe aortic stenosis undergoing TAVI with the third-generation 18-F CoreValve device in 8 Italian centers were prospect ively included in the Clinical Service Project . For the purpose s of this study , we included only consecutive patients with 5-year follow-up data available ( n = 353 ) treated from June 2007 to August 2009 . All outcomes were reported according to VARC ( Valve Academic Research Consortium)-1 criteria . RESULTS All-cause mortality rates at 1 , 2 , 3 , 4 , and 5 years were 21 % , 29 % , 38 % , 48 % , and 55.0 % , respectively . Cardiovascular mortality rates at 1 , 2 , 3 , 4 , and 5 years were 10 % , 14 % , 19 % , 23 % , and 28.0 % , respectively . The overall neurological event rate at 5 years was 7.5 % , of which more than two-thirds occurred early after the procedure . During follow-up , there were 241 rehospitalizations for cardiovascular reasons in 164 ( 46 % ) patients . Among all rehospitalizations , acute heart failure was the most frequently reported ( 42.7 % ) , followed by requirement of permanent pacemaker implantation ( 17.4 % ) . On echocardiography , mean transaortic gradients decreased from 55.6 ± 16.8 mm Hg ( pre-TAVI ) to 12.8 ± 10.9 mm Hg ( 5-year post-TAVI ) ( p < 0.001 ) . Late prosthesis failure occurred in 5 cases ( 1.4 % ) ; among these , redo TAVI was successfully carried out in 2 patients ( 0.6 % ) presenting with symptomatic prosthesis restenosis . The remaining 3 cases of prosthesis failure did not undergo further invasive interventions . Ten patients ( 2.8 % ) showed late mild stenosis with a mean transaortic gradient ranging from 20 to 40 mm Hg . No other cases of structural or nonstructural valvular deterioration were observed . Valve thrombosis or late valve embolization were not reported . CONCLUSIONS TAVI with the currently adopted CoreValve generation was associated with sustained clinical outcomes up to 5-year follow-up , with a low rate ( 1.4 % ) of significant prosthetic valve degeneration . The procedure appears to be an adequate and lasting resolution of aortic stenosis in selected high-risk patients


Title 4:
Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
Abstract 4:
BACKGROUND Clinical outcomes were compared among patients with previous cardiac surgery undergoing transcatheter aortic valve implantation ( TAVI ) or surgical aortic valve replacement ( AVR ) .  METHODS Between 2007 and 2014 a total of 142 consecutive patients with previous cardiac surgery were treated by TAVI  either by the transfemoral ( n=68 ) or transapical access ( n=74 ) , and 236 patients underwent a surgical redo-AVR .  Of these patients , propensity analysis ( m : n ) matched 62 ( group 1 , TAVI ) and 51 patients ( group 2 , redo-AVR ) . A multivariate logistic regression model was constructed . Moreover , mortality was compared between both groups by Cox regression . RESULTS Both groups differed significantly ( p<0.01 ) in regard to age and preoperative risk scores ( EuroSCORE and STS-Score ) . Thirty-day mortality was 14.5 % ( 9/62 ) in group 1 and 5.8 % ( 3/51 ) in group 2 ( p=0.23 ) . Risk-adjusted multivariable analysis revealed only the logistic EuroSCORE to be strongly correlated with 30-day mortality ( p=0.01 ) . Multivariate analysis showed no difference in 30-day mortality between both groups ( p=0.21 ) . Multivariate Cox regression revealed New York Heart Association functional class ( p=0.001 ) , logistic EuroSCORE ( p=0.01 ) , and STS-Score ( p=0.03 ) to be strongly associated with overall mortality . Moreover , evaluating overall mortality , Cox regression showed no difference between both groups ( p=0.36 ) . CONCLUSIONS The present study shows that in patients with cardiac reoperation , TAVI comes with similar outcomes when compared to surgical AVR . On the other h and , conventional redo-AVR is still a valuable and safe treatment option
CONCLUSIONS Patients with previous CABG who underwent TAVR had similar perioperative and long-term survival while experiencing more pacemaker implantations and shorter hospital stay compared to those who had SAVR making TAVR a safe and efficacious alternative to SAVR