A quantitative study of XXXX deposition in the aortic wall following Medtronic Freestyle compared with homograft aortic root replacement. A prospective randomized trial.

@entity730 @entity1 @entity460
BACKGROUND AND AIM OF THE STUDY: Unstented aortic valve substitutes offer many of the theoretical advantages of homografts such as superior hemodynamic performance and enhanced durability, particularly when inserted as a root. Many of these depend on the maintained flexibility of the valve components. Calcification of the aortic wall may adversely affect these phenomena. Electron beam computed tomography has been used to evaluate aortic wall @entity730 in @entity1 undergoing aortic root replacement in a prospective randomized trial designed to compare the Medtronic Freestyle valve with the homograft valve replacement. METHODS: @entity1 were followed with electron beam computed tomography scans of the aortic root at six-monthly intervals after surgery. A @entity730 score (Hounsfield units) and a calcified volume score (mm3) were obtained from each scan using a new modified technique. Results were related to hemodynamic data from echocardiography. The prevalence of @entity730 was also related to the homograft donor age. RESULTS: Seventy-six @entity1 (age range: 40-79 years) were randomized to root replacement with either homograft (n = 31) or Freestyle (n = 45) valves. Fifty-three scans of the aortic root were performed postoperatively in 37 @entity1 . No statistical difference between the two groups was found at six and 12 months after surgery. However, after 18 months the calcified volume score was 5903.8+/-2356.8 mm3 in the homograft versus 2725.6+/-1500.5 mm3 in the Freestyle group (p = 0.017). There was a correlation between @entity730 score, calcified volume score and left ventricular mass (r = 0.323, p = 0.093 and r = 0.350, p = 0.068, respectively) on the one hand, and @entity730 score, calcified volume score and valve size on the other hand (r = 0.178, p = 0.466 and r = 0.068, p = 0.780, respectively). CONCLUSIONS: Electron beam computed tomography provides a powerful tool for the detection of @entity460 in the aortic wall of valve grafts. There is a low rate of @entity730 during the first 18 months in the Medtronic Freestyle valve, and this appears to be lower than that observed in homografts. Longer-term follow up of the aortic root in these @entity1 is required. This is an ongoing study.
