Refinement of risk stratification in patients with acute pulmonary embolism by visual assessment of coronary artery calcifications on thoracic computed tomography

Background Coronary artery calcifications (CAC) are frequently detected incidentally on chest CT performed for suspected pulmonary embolism (PE). Their prognostic relevance and potential role in refining PE risk stratification remain insufficiently explored. Purpose To assess the prognostic impact of visually graded CAC on CT pulmonary angiography (CTPA) in patients with acute PE and to evaluate their contribution to reclassifying risk beyond the simplified PESI (sPESI) score and ESC 2019 guidelines. Methods This single center retrospective study included 475 consecutive patients diagnosed with PE by CTPA between 2016 and 2019. CAC were visually graded (0: none, 1: mild, 2: moderate, 3: severe). The primary outcome was a 30-day composite of all-cause death, myocardial infarction (MI), coronary revascularization, stroke, hospitalization for heart failure, and major bleeding. Secondary outcomes included 1- short term outcome: PE related death and all death at 30 days, and 2- Five-year extended MACE including cardiovascular mortality, MI, coronary revascularization, ischemic stroke, peripheral arterial events, and hospitalization for heart failure Results CAC were observed in 70.3% of patients. Moderate-to-severe CAC (grades 2–3) or a history of ischemic heart disease (IHD) were associated with older age and higher comorbidities. Thirty-day all-cause mortality and PE-related death were significantly higher in patients with CAC 2–3 or IHD compared to those without (15.5% vs 6.0%, p=0.0013 and 8.8% vs 2.5%, p=0.0027, respectively). In multivariate Cox analysis adjusted for comorbidities, CAC 2–3 remained an independent predictor of the primary outcome (HR=1.43 [1.07–1.91], p=0.015) and extended MACE (HR=3.22 [1.74–5.97], p<0.001). Integrating CAC grading into the clinical risk model refined the risk stratification, reclassifying 22.2% of low- and intermediate-low–risk patients into higher risk categories. Conclusion Visual CAC assessment on routine CTPA is a simple, and independent predictor of adverse cardiovascular outcomes after PE. At no additional cost or radiation, integrating CAC assessment provides a valuable "safety net" to identify high-risk patients who are underestimated by clinical scores alone.