title: Minimal invasive aortic valve replacement surgery is associated with improved survival: a propensity-matched comparison.
abstract: OBJECTIVE
  To compare early and long-term outcomes of minimally invasive surgery (MIS) versus full sternotomy (FS) isolated aortic valve replacement (AVR).
  
  
  METHODS
  We retrospectively analysed all patients who underwent isolated bioprosthetic AVR between 2003 and March 2012 at our institution. Matching was performed based on a propensity score, which was obtained using the output of a logistic regression on relevant preoperative risk factors. Mean follow-up was 3.1±2.7 years (range 0-9.0 years) and was 99.8% complete.
  
  
  RESULTS
  A total of 2051 patients (FS, 1572; MIS, 479) underwent isolated bioprosthetic AVR during the study period. MIS patients were significantly younger (67.8±11.2 vs 70.4±9.4 years) and had a lower logistic EuroSCORE (6.6±6.4 vs 11.2±13.4%, both P<0.001). Propensity matching resulted in 477 matched patients from each group, with no significant differences in any of the preoperative variables. Aortic cross-clamp times were significantly longer in MIS patients (59.4±16.0 vs 56.9±14.6 min, P=0.008). Nonetheless, MIS AVR was associated with a significantly lower incidence of intra-aortic balloon pump usage (0.4 vs 2.1%, P=0.042) and in-hospital mortality (0.4 vs 2.3%, P=0.013), while FS patients had a lower rate of re-exploration for bleeding (1.5 vs 4.2%, P=0.019). Five- and 8-year survival post-AVR was significantly higher in MIS patients (89.3±2.4% and 77.7±4.7% vs 81.8±2.2% and 72.8±3.1%, respectively, P=0.034). Cox regression analysis revealed MIS (hazard ratio: 0.47, 95% confidence interval: 0.26-0.87) as an independent predictor of long-term survival.
  
  
  CONCLUSIONS
  MIS AVR is associated with very good early and long-term survival, despite longer myocardial ischaemic times. MIS AVR can be performed safely with results that are at least equivalent to those achieved through an FS.
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Denis R
authors.initials: DR
authors.lastname: Merk
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Lehmann
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: David M
authors.initials: DM
authors.lastname: Holzhey
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Pascal
authors.initials: P
authors.lastname: Dohmen
authors.affiliation: Edwards Lifesciences SA, Nyon, Switzerland.
authors.forename: Pascal
authors.initials: P
authors.lastname: Candolfi
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Misfeld
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Mohr
authors.affiliation: Department of Cardiac Surgery, Leipzig Heart Center, University of Leipzig, Leipzig, Germany michael.borger@med.uni-leipzig.de.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Borger
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods / Q000401:mortality*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000401:mortality*; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies
keywords: Aortic valve replacement; Minimally invasive