Impact of full root implantation of stentless aortic valves on clinical outcome: A propensity score analysis

Purpose: We assessed the effect of full root implantation technique of the Freestyle stentless bioprosthesis on clinical outcome, while adjusting for patient and disease characteristics by a propensity score. Methods: Between April 1996 and September 2004, 681 patients underwent AVR with the stentless Medtronic Freestyle bioprosthesis in our institute. The mean age of the study population was 74±6 years. In 98 (14%) patients the aortic valve was replaced in total root implantation technique. The propensity score was the probability of receiving total root replacement (TRR) and was included along with the comparison variable in multiple regression analysis of outcome. Results: Predictive factors for TRR were body size (p=0.004; OR=0.96), dilatation of ascending aorta (p5 days (p=0.15). The c-statistics for these regression models were 0.75, 0.7 and 0.72, respectively. The propensity score was in all models not significant. Conclusions: Total root implantation technique did neither increase the operative risk nor the risk for re-thoracotomy or prolonged stay in ICU, whereas these patients may benefit from lower gradients measured at discharge.