Background--Aortic root rupture is a major concern with balloon-expandable transcatheter aortic valve replacemen (TAVR). We sought to identify predictors of aortic root rupture during balloon-expandable TAVR by using multidetecto computed tomography. Methods and Results--Thirty-one consecutive patients who experienced left ventricular outflow tract (LVOT)/annular, aortic contained/noncontained rupture during TAVR were collected from 16 centers. A caliper-matched sample of 31 consecutive patients without annular rupture, who underwent pre-TAVR multidetector computed tomography servec as a control group. Multidetector computed tomography assessment included short- and long-axis diameters and cross sectional area of the sinotubular junction, annulus, and LVOT, and the presence, location, and extent of calcificatioi of the LVOT, as well. There were no significant differences between the 2 groups in any preoperative clinical anc echocardiographic variables. Aortic root rupture was identified in 20 patients and periaortic hematoma in 11. Patient! with root rupture had a higher degree of subannular/LVOT calcification quantified by the Agatston score (181.2±211.( versus 22.5±37.6, P<0.001), and a higher frequency of ⩾20% annular area oversizing (79.4% versus 29.0%, P<0.00i; and balloon postdilatation (22.6% versus 0.0%, P=0.005). In conditional logistic regression analysis for the matched data moderate/severe LVOT/subannular calcifications (odds ratio, 10.92; 95% confidence interval, 3.23-36.91; P<0.001) anc prosthesis oversizing ^20% (odds ratio, 8.38; 95% confidence interval, 2.67-26.33; P<0.001) were associated with aortic root contained/noncontained rupture. Conclusions--This study demonstrates that LVOT calcification and aggressive annular area oversizing are associated wit! an increased risk of aortic root rupture during TAVR with balloon-expandable prostheses. Larger studies are warranted tc confirm these findings. [ABSTRACT FROM AUTHOR]