Abstract 4781: Rate of Progression and Functional Significance of Aortic Valve and Root Calcification Up To 8 Years Following Total Aortic Root Replacement Using a Homograft Versus Freestyle Prosthesis: Results From a Prospective Randomized Trial

Abstract

Introduction - Aortic root calcification is a major limitation following root replacement. The aims of this analysis were to compare the rate of progression of root calcification between homografts and xenografts (Medtronic Freestyle) up to 8 years postoperatively and to determine its functional significance. Methods - Between 1997 and 2003, 161 patients were prospectively randomized to undergo homograft (Group H) or Freestyle (Group F) total aortic root replacement. Of those, 99 patients underwent a total of 248 electron beam computed tomography (EBCT) studies at 0.5, 1, 1.5, 2, 3 and 8 years (n=17 patients at 8 years). Aortic root calcium scores were calculated using Agatston scores. Results - Mean calcium scores in Group H at 1, 2, 3 and 8 years were 550±95, 1026±160, 1440±256 and 3876±604 Hounsfield Units (HU), versus 397±84, 556±125, 683 ±151 and 2518±495 HU in Group F. Mixed effects models show higher calcium scores in Group H at 1, 2 and 3 years, with a trend at 8 years (p=0.11). Group H presents a significantly more rapid early rate of progression (slope from 0 to 3 years; p=0.02) and progress similarly to Group F thereafter (slope from 3 to 8 years; p=0.3) (Figure 1 ). Echocardiographic evaluation of patients at 8 years showed no correlation between EBCT scores and aortic valve dysfunction. Conclusion - Homograft roots have a higher propensity to calcifiy than Freestyle prostheses, which follows a time-dependent progression marked by rapid early calcification. Despite the high calcium scores, no correlation with prosthetic valve function was identified at 8 years.