Coronary artery calcification as a predictor of adverse outcomes in patients hospitalized with COVID-19

BACKGROUND: Subclinical coronary artery calcification (CAC) is a risk factor for adverse cardiovascular events, but studies investigating its association with outcomes in hospitalized patients with COVID-19 are limited. METHODS: This was a retrospective study of 457 patients without history of clinical coronary artery disease (CAD) who underwent chest CT imaging during COVID-19 hospitalization at MCW/Froedtert-affiliated hospitals from July 1, 2020 to July 1, 2021. Visually estimated CAC (yes/no) and CAC burden (none/mild/moderate/severe) were recorded from radiology reports. Unadjusted and adjusted regression models were used to assess associations between CAC and hospital length of stay (LOS), ICU admission, mechanical ventilation, and mortality. RESULTS: The mean age was 63.1 ± 15.3 years. Presence of CAC was associated with mechanical ventilation (p = 0.01), ICU admission (p = 0.02), in-hospital or 30-day mortality (p < 0.01), and hospital LOS (p < 0.001). Compared to no CAC, hospital LOS was increased for mild (p = 0.01) and severe CAC (p = 0.02) after adjustment for covariates. Severe CAC was also associated with increased ICU admission (OR 3.97; p = 0.002) and mechanical ventilation (OR 3.08; p = 0.03) after adjustment. In unadjusted analysis, in-hospital or 30-day mortality increased with magnitude of CAC severity, with HR 2.43 (p = 0.003) for mild and HR 3.70 (p = 0.002) for severe CAC. However, associations with mortality were not significant after adjustment. CONCLUSIONS: CAC is associated with increased ICU admission, mechanical ventilation, hospital LOS, and in-hospital or 30-day mortality for patients hospitalized with COVID-19. Patients with severe CAC, and without clinical history of CAD, represent a high-risk population for morbidity and mortality.