THE CLINICAL OUTCOME AFTER AORTIC VALVE REPLACEMENT WITH FREEDOM SOLO STENTLESS BIOPROSTHESIS IN NORTH AMERICA - A SINGLE CENTER EXPERIENCE

Abstract

The Freedom SOLO stentless bioprosthesis has been widely used in Europe as an option for stentless aortic valve replacement. In North America however, this valve has not been broadly used. We are reporting the first short and midterm clinical outcomes of aortic valve replacement(AVR) with Freedom SOLO stentless bioprosthesis in a single North American center. This is a retrospective study using the existing database and patients charts at the University of Alberta Hospital and Mazankowski Alberta Heart Institute. From February 2011 to October 2013, 189 consecutive patients 126(66.7%) male with a mean age of 71.8±10.4 years (19-90 years) underwent aortic valve replacement with the Freedom SOLO stentless bioprosthesis. All patients were included in this study, 39 patients had isolated AVR and 150 had combined procedures. Univariate and multivariate analysis were performed and significant values (p<0.05) were reported. All patients had a pre-operative and at least one postoperative echo study done. The 30 day post-operative mortality for isolated AVR and combined procedures were 0%(n=0) and 4.2%(n=8) respectively. There was no structural valve degeneration or perivalvular leaks during the entire follow up period, however mild central aortic regurgitation was found in 5(3%) patients. Mean cross-clamp time for isolated aortic valve replacement and combined procedures were 78.3±17.8min and 91.5±16.6 min respectively. The mean cardiopulmonary bypass time for isolated AVR and combined procedures were 127.2±43.2 min and 163.5±50.3 min respectively. Echocardiographic results in the immediate postoperative period showed a significant decrease in mean and peak transvalvular gradients. The mean gradient decreased from 39.4±17.5mmHg to 8.2±4.9mmHg and peak gradient decreased from 67.9±30.0mmHg to 16.7±9.7mmHg. The postoperative effective orifice area(EOA) increased from 0.87 to 1.94cm2 and the effective orifice area index (EOAi) increased from 0.45 to 1.00 cm2/m2 which were also significant. There was a significant LV mass regression (215.4 to 178.6g) that took place within six months postoperatively. Left ventricular ejection fraction was unchanged during the course of this study. At 30 days follow-up, ten patients (5.3%) had complete heart block requiring permanent pacemaker insertion. Our experience shows that the Freedom SOLO bioprosthesis has an overall good short and midterm clinical and hemodynamic outcomes.