A single-center experience with the Sorin Mitroflow pericardial aortic valve: hemodynamics up to five years

The authors' institution participated in a 28-center FDA Investigational Device Exemption study to evaluate the Sorin Mitroflow pericardial aortic bioprosthesis. Six high-enrolling sites evaluated patients on an annual basis as part of an ongoing hemodynamic study. These data represent patients followed for an average of five years after implant, with annual echocardiography.

Seventy-one patients were entered into the study and constitute the basis of this review. Mean follow up was 3.3 +/- 2.0 years (range: 0-5.5 years), with a cumulative follow up of 233 patient-years. The mean patient age was 73.8 years (range: 45-89 years), and 52% were males. The majority of aortic valve lesions were stenosis (63%) or mixed (30%), and nine patients (12.7%) were reoperations. Sixty-one patients (86%) had concomitant procedures, the most common being coronary artery bypass grafting (70%).

A total of 281 echocardiograms was obtained from the patients over a five-year period. The largest number of echocardiograms was obtained with 23-mm valve implants (n = 122), followed by 25 mm valve implants (n = 87). The early baseline (30-day) mean gradient was < or = 10 mm in all patients. The mean gradient decreased as the valve size increased (21 mm valve gradient = 10.0 +/- 5.6 mmHg; 27 mm valve gradient = 6.2 +/- 2.2 mmHg). The mean increase in gradient at five years was < 7 mmHg, with a trend towards increased gradients at smaller valve sizes. The effective orifice area (EOA) showed a trend to decline slightly with 21 mm valves (from 1.5 to 1.2 cm2) and 23 mm valves (1.4 to 1.2 cm2), but there was either no change or a slight increase in larger-size valves. Left ventricular mass regression occurred mainly within the first year (18.9%), but then remained stable throughout the study period. No greater than mild prosthetic aortic valve regurgitation was observed over the study period.

The Sorin Mitroflow aortic valve provides excellent hemodynamic results up to five years, with minimal increase in mean gradients, acceptable peak gradients, and good EOAs with all valves sizes.