Coronary and Thoracic Aortic Calcium is an Independent Predictor of Poor Outcome in Patients Referred to Non-contrast Chest Computed Tomography

Background: Vascular and valvular calcium in chest computed tomography (CT) is used to be out of scope. We aimed to evaluate the association between thoracic aortic, coronary and valvular calcium scores on MACE and mortality of patients referred to chest CT due to non-cardiac indications.

Methods: Non-contrast non ECG-gated chest CT scans of 415 consecutive patients (mean age 67 years, 52% male) from Assuta Medical Center were analyzed for coronary artery calcium (CAC), thoracic aortic calcium (TAC) (ascending, arch and descending aorta included), aortic valve (AoV) and mitral annular calcium (MAC) scores. Calcium scores were quantitated using the Agatston method and were categorized into commonly accepted categories of CAC or sample-derived tertiles of TAC, AoV and MAC. Data on MACE and mortality were retrieved from the database of the patients’ health care provider. Multivariate Cox proportional regression models were used to assess associations between calcium scores and outcomes.

Results: 37 MACE and 107 all-cause deaths were recorded during a median follow-up of 9 years (inter-quartile range: 7.4 -10.4). Adjusting for age and sex, compared to patients with CAC = 0, the highest category (≥ 400) of CAC score was independently associated with all-cause mortality [HR = 1.84 (95% confidence interval: 1.05 – 3.21; p=0.033)] and with MACE [HR = 3.17 (1.11 - 9.00; p=0.032)]. Compared to TAC = 0, TAC’s highest tertile (≥ 440) was an independent predictor of all-cause mortality [HR = 2.79 (1.56 - 4.98; 0.001)], but not of MACE. AoV calcium and MAC scores were not found to be predictors of these adverse outcomes.

Conclusions: CAC and TAC were found to be independent predictors of MACE and of all-cause mortality, respectively. Reporting of CAC and TAC from non-contrast chest CT is important and may potentially drive intervention to improve the patient’s prognosis.