A Novel Iliac Morphology Score Predicts Procedural Mortality and Major Vascular Complications in Transfemoral Aortic Valve Replacement

Background: Vascular complications remain a significant technical challenge for transfemoral TAVR (transcatheter aortic valve replacement). The goal of this study is to develop a preoperative tool for prediction of major vascular complications of TAVR. Methods: A retrospective review was performed of all patients who underwent transfemoral TAVR at a tertiary medical center from 2011 to 2015. Iliofemoral arterial measurements were obtained with computed tomography angiography three-dimensional reconstruction images and an Iliac Morphology Score (IMS) was created from these measurements. Vascular complications were defined by Valve Academic Research Consortium (VARC-2) criteria. Statistical analyses were performed utilizing chi-squared test, Student's t-test, and binomial regression. Results: We analyzed the data of 198 transfemoral TAVR patients. VARC-2 vascular complications were seen in 25 patients (13%). Major and minor vascular complication rates in the entire cohort were 4%(n = 7) and 9%(n = 18), respectively. Thirty-one patients (15.6%) required vascular surgery consultation. A total of 24 patients (12%) required surgical or percutaneous vascular interventions. Univariate analysis identified gender, iliac diameter, iliac calcification, and access type (open versus percutaneous) as predictors of major complications. The IMS was composed of ipsilateral minimum iliac diameter and iliac calcifications based on area under the receiver operator curve (AUROC) analysis (P < 0.05, AUROC = 0.82). Arterial size and calcification were classified with a value of 0-3 based on severity. Multivariate analysis identified gender and IMS as independent predictors of major complications. The mean IMS for the cohort was 3.4 (range 0-6). Patients were divided into high (IMS >= 5, n = 55) and low risk (IMS< 5, n = 143) groups based on the inflection point for specificity (73%) and sensitivity (83%). The high-risk group had smaller iliac diameters, areas, luminal volumes, and a higher rate of major vascular complications (9% vs. 1%, P = 0.001). The 30-day mortality rate in the high score group was 9% and 1.4% in low score group (P = 0.02, AUROC = 0.72). Conclusions: An IMS composed of ipsilateral minimum iliac diameter plus iliac calcification is an excellent predictor of major vascular complications and mortality. Alternative access in patients with high IMS may reduce major vascular complications and 30-day mortality.