Abstract 17893: Reducing Radiation Exposure and Contrast Use in Pre-TAVR Evaluation by Computed Tomography Angiography (CTA): A Quality Improvement Project
Introduction: Aortic stenosis is the most common valvular heart disease with a prevalence of 13% in patients ≥75 years of age. Transcatheter aortic valve replacement (TAVR) has become a widely utilized alternative to surgical valve replacement. Our conventional CTA protocol for TAVR planning used 120mL of iodinated contrast with a tube voltage of 120kV. The risk of contrast-induced nephropathy (CIN) in this elderly population limited the use of CTA.
Purpose: We sought to develop a CTA protocol using a high-pitch spiral acquisition mode to reduce radiation dose and contrast volume without compromising diagnostic image quality.
Methods: 125 consecutive patients underwent CTA-TAVR evaluation using a dual-source scanner. Following an injection of 50 mL of contrast, retrospectively gated imaging of the heart followed by a rapid high pitched spiral was acquired from thoracic inlet through the ischial tuberosity using tube voltages of 80kV and 120kV, respectively. These studies were compared to a conventional protocol in 125 patients with retrospective gated acquisition of the chest and a non-gated technique of abdomen and pelvis, which utilized 120mL of contrast and tube voltage of 120kV. Two-tailed t-test was performed to evaluate differences between groups.
Results: Table 1 shows baseline patient and imaging characteristics. The low dose protocol significantly reduced radiation dose to 11.6±5.7mSv from 31.1±10.6mSv (p<0.0001) and contrast amount 50 mL versus 120mL (p<0.01). The low dose protocol showed comparable LVOT Hounsfield units, signal-to-noise ratio, and contrast-to-noise ratio. Interpretability of each study was 100% without any reported CIN in the low dose protocol group.
Conclusion: Our CTA protocol for pre-TAVR assessment of high risk patients significantly reduces both radiation exposure and contrast load compared to conventional CTA protocol without sacrificing imaging quality or diagnostic utility.
Author Disclosures: E.M. Holland: None. A.I. Loffler: None. J.A. Gonzalez: None. C.K. Lamie: None. P.W. Shaw: None. P.C. Balfour: None. C.M. Kramer: None. M. Salerno: None. K. Hagspiel: None. P. Norton: None.
- © 2016 by American Heart Association, Inc.