Hemodynamic Performance of the PRIMATMEdwards Stentless Aortic Xenograft: Early Results of a Multicenter Clinical Trial

Between June 1991 and July 1993, 200 PRIMA Edwards stentless aortic bioprostheses were implanted in 4 European centres. Mean age of the group was 68.5 years (S.D. 8.0). The subcoronary implantation technique was used in 161 patients, the inclusion cylinder technique in 39 patients. Valve diameters ranged from 19 mm to 29 mm. Transthoracic Doppler echocardiographic studies were performed at discharge, and after 6 months and 12 months; a complete one-year follow-up was obtained. At 12 months peak systolic gradients ranged from 35.2 mmHg (19 mm valve) to 10.9 mmHg (29 mm valve) and effective orifice area ranged from 0.8 cm2 (19 mm valve) to 2.8 cm2 (29 mm valve). 30-day mortality was 3%, 12-month mortality was 5%. Complications were thrombo-embolism in six patients (3%), haemorrhage in three patients (1.5%), endocarditis in two patients (1%), and total AV-block requiring an endocavitary pacemaker in 14 patients (7%). At one year aortic regurgitation was evident in 27% patients but only one patient showed grade III. The stentless xenograft still offers good hemodynamics at one year. Morbidity and mortality are acceptable. Evaluation of the long-term performance of this new type of xenograft will be an important issue in future.