Implication of thoracic aortic calcification over coronary calcium score regarding the 2018 ACC/AHA Multisociety cholesterol guideline: results from the CAC Consortium

Donghee Han; Keiichiro Kuronuma; Alan Rozanski; Matthew J Budoff; Michael D Miedema; Khurram Nasir; Leslee J Shaw; John A Rumberger; Heidi Gransar; Roger S Blumenthal; Michael J Blaha; Daniel S Berman

doi:10.1016/j.ajpc.2021.100232

Implication of thoracic aortic calcification over coronary calcium score regarding the 2018 ACC/AHA Multisociety cholesterol guideline: results from the CAC Consortium

Am J Prev Cardiol. 2021 Aug 8:8:100232. doi: 10.1016/j.ajpc.2021.100232. eCollection 2021 Dec.

Authors

Affiliations

¹ Department of Imaging and Medicine, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, United States.
² Division of Cardiology, Mount Sinai St. Luke's Hospital, New York, United States.
³ Department of Medicine, Harbor-UCLA Medical Center, University of California Los Angeles, Los Angeles, CA, United States.
⁴ Minneapolis Heart Institute and Minneapolis Heart Institute Foundation, Minneapolis, MN, United States.
⁵ Division Cardiovascular Prevention and Wellness, Houston Methodist Hospital, Houston, TX, United States.
⁶ Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, New York United States.
⁷ Princeton Longevity Center, Princeton, NJ, United States.
⁸ Johns Hopkins Ciccarone Center for Prevention of Cardiovascular Disease, Johns Hopkins University, Baltimore, MD, United States.

Abstract

Objective: TAC is associated with an increased atherosclerotic cardiovascular disease (ASCVD) risk, but it is unclear how to interpret thoracic aortic calcification (TAC) findings in conjunction with ASCVD risk and coronary artery calcium (CAC) score according to 2018 ACC/AHA Multisociety cholesterol guidelines. We evaluate the incremental value of thoracic aortic calcification TAC over CAC for predicting and reclassifying ASCVD mortality risk.

Method: The study included 30,630 asymptomatic individuals (mean age: 55 ± 8 years, male: 64%) from the CAC Consortium. TAC was categorized as TAC 0, 1-300, and >300. Patients were categorized as low (<5%), borderline (5-7.5%), intermediate (7.5-20%), or high (≥20%) 10-year ASCVD risk according to the Pooled Cohorts Equation. In the intermediate risk group, the utility of TAC beyond CAC for statin eligibility was assessed according to the guideline. CAC was categorized as CAC=0 (no statin), CAC 1-100 (favors statin), or CAC>100 (initiate stain).

Results: During the median 11.2 years (IQR 9.2-12.4) follow-up, 345 (1.1%) CVD deaths occurred. TAC>300 was associated with increased CVD mortality after adjusting for ASCVD risk and CAC (HR:4.72, 95% CI: 3.39-6.57, p<0.001). In borderline and intermediate risk groups, TAC improved discrimination when added to a model included ASCVD risk and CAC (C-statistic: 0.77 vs. 0.68 in borderline group; 0.67 vs. 0.63 in intermediate group, both p < 0.05). The addition of TAC over CAC improved risk reclassification in borderline, intermediate and high-risk groups (categorical net reclassification index: 0.40, 0.29, and 0.49, respectively, all p < 0.001). Of intermediate risk participants for whom consideration of CAC was recommended based on the guideline, TAC >300 was associated with an increased CVD mortality risk across each statin eligibility group (all p < 0.001, compared to TAC 0).

Conclusion: TAC was independently associated with CVD death. Among individuals with borderline or intermediate ASCVD risk, a TAC threshold of 300 may provide added prognostic and reclassification value beyond the current guideline-based approach.

Keywords: Cardiovascular mortality; Computed tomography; Coronary artery calcium; Prognosis; Thoracic aortic calcification.