Abstract 14845: Ultra-Low-Dose Contrast Computed Tomographic Angiography Protocol for Octogenarians Being Evaluated for Transcatheter Aortic Valve Replacement: Effect on Image Quality and Outcomes
Introduction: Transcatheter aortic valve replacement (TAVR) necessitates aortoiliofemoral assessment by contrast-enhanced computed tomographic (CT) angiography to determine eligibility of a transfemoral approach. As many candidates considered for TAVR have chronic kidney disease (CKD), we implemented a standardized ultra-low-dose contrast protocol (LCP) by direct intra-aortic injection of contrast (5F pigtail) in patients at risk of contrast induced nephropathy (CIN), and studied image quality and patient outcomes following institution of the LCP protocol.
Methods: 54 consecutive patients ≥80 years old being considered for TAVR were categorized into 3 groups:1) those imaged by traditional contrast protocols (TCP) prior to LCP initiation (n=21), 2) those imaged by TCP after implementation of LCP (n=17), and 3) those imaged by LCP (n=16). The protocol utilized LCP imaging in patients considered at risk of CIN by an effective glomerular filtration rate (eGFR) of ≤60 ml/min/1.73m2 or by the caring interventional cardiologist; TCP was utilized in the remaining patients or those who were not LCP candidates. Two blinded independent readers determined image interpretability and quality by Likert scores (1-4); the signal and noise were measured bilaterally in common iliac and common femoral arteries. Adverse events included CIN (≥25% or ≥0.5 mg/dl creatinine increase ≥48 hours after CT), vascular complications due to aortic pigtail catheter placement, non-interpretable CTs, or TAVR procedures that were aborted due to vascular access complications.
Results: Patient and CT variables and outcomes are provided in Table 1. Following protocol implementation, LCP was associated with an 82% reduction in contrast volume (p<0.001). Both LCP and TCP yielded high quality images. There were no differences in adverse outcomes despite significantly lower eGFR in the LCP group.
Conclusion: A LCP is effective and safe for at-risk octogenarians being considered for TAVR.
- © 2011 by American Heart Association, Inc.