[Experience and learning curve with transapical aortic valve implantation]

Abstract

Background and purpose: Transapical transcatheter aortic valve implantation has emerged as an alternative to conventional aortic valve replacement in high-risk patients with degenerative aortic valve stenosis. The aim of this study was to assess a potential learning curve with the former technique based on the own experience with this novel procedure.

Patients and methods: 40 consecutive high-risk patients (82 +/- 5 years, logistic EuroSCORE 42% +/- 16%) with symptomatic aortic valve stenosis underwent transapical aortic valve implantation (balloon expandable Sapien bioprosthesis, Edwards Lifesciences, Irvine, CA, USA) in the hybrid operating room between October 2007 and May 2009 at the West German Heart Center Essen. To assess a potential learning curve, patients were allocated and compared according to the implantation date (initial n = 20: 10/2007 to 10/2008; second n = 20: 11/2008 to 05/2009).

Results: All but one transapical aortic valve implantations were successful (procedural success rate 97.5%) and no prosthesis migration/embolization or coronary artery obstruction was observed. Comparing the groups, procedural time, fluoroscopy time, and contrast media volume decreased significantly (139 +/- 30 min vs. 112 +/- 41 min; 6.8 +/- 1.9 min vs. 5.5 +/- 1.5 min; 226 +/- 75 ml vs. 169 +/- 23 ml; p <or= 0,05). Predicted 30-day mortality for patients operated upon within the 1st period was 51% +/- 14% (logistic EuroSCORE) and 20% +/- 11% (STS Score [Society of Thoracic Surgeons]) compared to 32% +/- 12% and 13% +/- 7% in the 2nd period, while observed 30-day mortality decreased from 25% to 10%.

Conclusion: This study reflects the authors' experience with transapical aortic valve implantation in patients presenting with a high surgical risk for conventional aortic valve replacement. Within this patient cohort improved clinical outcome, and lower morbidity and mortality demonstrate a learning curve. Improved results were achieved by (1) patient selection with regard to specific procedure-related risk factors, (2) careful preoperative patient preparation, (3) an optimum interventional and surgical approach, and (4) continuous application of this new procedure.