The aims of this multicenter prospective observational trial were to evaluate: (i) the left ventricular remodeling, hemodynamics and early clinical outcomes of patients undergoing aortic valve replacement (AVR) with the Pericarbon Freedom (PF) stentless bioprosthesis; and (ii) the impact of the two suture techniques--continuous and interrupted--on the hemodynamic performance of the bioprosthesis. Between November 2001 and April 2004, a total of 226 patients (131 females, 95 males; mean age 73.2 +/- 8.8 years) underwent AVR with the PF valve (Sorin Group, Saluggia, Italy) at eight Italian cardiac surgery centers. Associated surgery was performed in 73 patients (32%); of these operations, 54 were coronary artery bypass grafting. A continuous-suture technique was used in 132 patients (58%), and an interrupted-suture in 90 (40%). The suture technique was not available for four patients. All patients underwent clinical and echocardiographic evaluation immediately before surgery, and at one, six, and 12 months thereafter. The median follow up was 380 days (Q1: 363 days; Q3: 410 days), and the total cumulative follow up 236.9 patient-years (pt-yr). The overall 30-day mortality was 3.5% (n = 8). Late deaths occurred in 10 patients (4%/pt-yr), of which three were valve-related (1%/pt-yr). The overall and valve-related survivals at one year were 92 +/- 2% and 98 +/- 1%, respectively. Freedom from structural valve deterioration, endocarditis, reoperation and thromboembolic events was 100%, 93 +/- 1%, 98 +/- 1% and 99 +/- 1% at one year, respectively. The peak and mean transprosthetic gradients at one year were: 19.7 +/- 12.27 and 8.7 +/- 6.0 mmHg, respectively. After 12 months, significant reductions (compared to preoperative) were observed in the left ventricular mass (148.5 +/- 48.8 versus 194.4 +/- 54.6 g/m2; p < 0.001) and mean wall thickness (1.08 +/- 0.19 versus 1.32 +/- 0.23 cm; p < 0.001). The continuous-suture technique showed a trend towards lower postoperative gradients than did the interrupted-suture technique. The data obtained indicated that the PF bioprosthesis provided excellent results in terms of left ventricular mass regression, hemodynamics, and early clinical outcome. Although a trend towards a better hemodynamic performance of the continuous-suture technique was observed, this aspect requires further evaluation.