Mid-term pattern of survival, hemodynamic performance and rate of complications after medtronic freestyle versus homograft full aortic root replacement: results from a prospective randomized trial.

BACKGROUND AND AIM OF THE STUDY: The full homograft root replacement has been regarded as the 'gold standard' for aortic valve replacement (AVR). Xenograft full root AVR may offer similar theoretical advantages, but no prospective randomized trials to compare the two valve substitutes have been reported to date.

METHODS: A total of 147 patients (mean age 66.2 years; range: 40-82 years) was randomized to undergo either Medtronic Freestyle (group F; n = 80) or homograft (group H; n = 67) root AVR. Coronary artery bypass grafting was associated with root AVR in 55 patients (37.4%). Follow up included routine clinical and echocardiographic assessments.

RESULTS: Overall, there were seven early deaths (4.8%). The early mortality rate for isolated root AVR was 2.1% in group F (1/47) and 2.2% in group H (1/45) (p = NS). There were four late deaths in group F, and two in group H. Actuarial survival was 83+/-5% and 84+/-4% (p = NS) at five years, in groups F and H, respectively. No patient required reoperation on the aortic valve. Overall, there were eight thromboembolic events and six anticoagulant-related bleeding events; these were equally divided between the two groups. After a median follow up of 45 months, most patients in both groups were in NYHA class I, and the mean trans-aortic gradient was 6+/-1 mmHg in group F and 5+/-2 mmHg in group H (p = NS). Mild aortic regurgitation was recorded in 1/26 patients (4%) of group F, and in 1/16 (6%) of group H.

CONCLUSION: The Medtronic Freestyle porcine xenograft appears to be a good alternative to homografts for full aortic root replacement, at least in the mid term.