Effect Of The Covid-19 Pandemic On Coronary Artery Calcium Testing And Subsequent Statin Prescription

Abstract

s Journal of Cardiovascular Computed Tomography 15 (2021) S1–S62 States Divisions of Radiology and Cardiovascular Disease, Scripps Clinic, La Jolla, CA, United States Scripps Whittier Diabetes Institute, Scripps Health, La Jolla, CA, United States Introduction: CAC scoring achieved Class IIA status in both the most recent AHA & ESC guidelines for risk stratification of asymptomatic moderate risk patients. Despite this endorsement, CAC scoring remains largely without insurance coverage due to the absence of randomized clinical trials. Advancements of iterative/deep learning reconstruction & volumetric CT has led to decreases in radiation dose while maintaining image quality. Methods: 4,215 prospective cases of CAC with-or-without CCTA obtained on 256 slice volumetric Revolution CT (GE Healthcare) at a single-site from 06/ 2016-11/2020. All exams were evaluated by Radimetrics (Bayer) using Monte Carlo simulation for the gated non-contrast series. Individualized gender & size specific equivalent organ doses & effective whole body doses (Deff) were generated using tissue weighting factors (WT) from IRCP 103. Continuous variables’ associations were tested using univariable linear regression. Median differences were compared between genders using Mann Whitney tests with Bonferroni correction for multiple comparisons. The population is 46.9% women, averaged 63 years (SD 11.9) with a mean BMI of 28kg/m2 (SD 6.1). 120 kVp was used for all exams, with 2.5 mm thick slices. Results: Deff was 0.61mSv (IQR: 0.47-0.85). Both BMI & water equivalent diameter (WED) were positively associated with both Size Specific Dose Estimate (SSDE)(mGy) & Deff (r‘s>0.6, p‘s<0.001). BMI was strongly associated with Deff (r1⁄40.70, p<0.001), & this association was observed while controlling for sex differences. Median organ-specific mSv were lower in every organ for women except breast (p<0.001); because of this, median Deff is higher in females (0.65 mSv) than males (0.59 mSv) (p<0.001). Conclusions: The results show that CAC scoring using a newer generation scanner requires very low radiation exposure while producing adequate studies with exposure equivalent to 2 months of natural background radiation&mid-glandular breast doses in women which are less than half that of a routine yearly bilateral mammogram. The negligible radiation required in CAC scoring allows consideration of more widespread screening to reach greater numbers of individuals.