Surgical risk algorithm as a measure of successful adoption of transapical transcatheter aortic valve implantation

ObjectiveThis study was performed to assess the Society of Thoracic Surgeons (STS) score as a measure of successful adoption of transapical transcatheter aortic valve implantation (TAVI).MethodsThe STS score for estimated surgical mortality was calculated and used to select the first 140 consecutive patients undergoing transapical TAVI. The STS score also was used to estimate postoperative morbidity. The comparisons were made between the observed and estimated mortality and morbidity in the entire group, as well as in the first 35, second 35, and last 70 consecutive patients.ResultsThe differences in outcomes between the first 35, second 35, and last 70 patients were statistically significant for surgical mortality (20.0% vs 14.3% vs 2.9%; P = .045), composite morbidity/mortality (34.3% vs 40.1% vs 15.7%; P = .020), and long length of stay (34.3% vs 45.7% vs 18.6%; P = .027). There were trends of marked decreases in prolonged ventilation (11.4% vs 20.0% vs 4.3%; P = .061), and acute renal failure (14.3% vs 20.0% vs 4.3%; P = .059). In the first 70 patients there were no significant differences between observed and STS estimated incidences in mortality and composite mortality/major morbidity. In the latter 70 patients the observed incidences were lower than STS predicted values in mortality (2.9% vs 9.6%; P = .056), composite major morbidity/mortality (15.7% vs 33.8%; P = .001), and prolonged ventilation (4.3% vs 25.1%; P < .0001).ConclusionsOnly after a protracted learning curve did the anticipated benefits of transapical TAVI materialize for patients at high risk for surgery as predicted by the STS risk algorithms.