5TH-YEAR HEMODYNAMIC PERFORMANCE OF THE PRIMA STENTLESS AORTIC-VALVE

Background. The medium-term hemodynamic performance of stentless valve s has not been widely reported, particularly in comparison with in vit ro studies. Therefore, we have assessed prospectively the hemodynamics of the Edwards Prima valve in its fifth year after implantation in th e aortic position, and compared the results with those at 1 month afte r implantation and also with in vitro data. Methods. Thirty-five patie nts (age, 77 +/- 6 years; 19 men) were prospectively studied by Dopple r echocardiography at 1 month and 52 +/- 8 months after implantation o f a Prima stentless valve. Valve hemodynamics were assessed by measuri ng the mean pressure gradient, mean valve resistance, and effective or ifice area. Left ventricular systolic function was quantified by eject ion fraction, the degree of hypertrophy by ventricular mass index, and the ratio of ventricular wall thickness to cavity radius as a measure of ventricular geometry. Results. With a mean valve size of 24.6 +/- 2.2 mm in the fifth year after implantation, the mean pressure gradien t was 6.2 +/- 3.5 mm Hg, the mean valve resistance, 29 +/- 16 dyne . s (-1) . cm(-5)), and the effective orifice area was 2.05 +/- 0.50 cm(2) . Compared with 1 month after operation, there was a 47% decrease in m ean valve resistance (p = 0.002) and a 39% increase in effective orifi ce area (p = 0.001). Furthermore, both effective orifice area and mean valve resistance in the fifth year did not differ from their in vitro counterparts, whereas the left ventricular ejection fraction (0.64 +/ - 0.14), the left ventricular mass index (119 +/- 49 g/m(2)), and the ratio of ventricular wall thickness to cavity radius (0.44 +/- 0.13) w ere within the normal range. Conclusions. This study suggests that the Prima valve is a reliable stentless aortic bioprosthesis. This is sup ported by a favorable medium-term clinical outcome, durable hemodynami c performance, and normal mean values of left ventricular ejection fra ction and mass index in the fifth year after implantation. (Ann Thorac Surg 1998;66:805-9) (C) 1998 by The Society of Thoracic Surgeons.