Incidental cardiovascular calcifications detected on screening CT: prognostic impact over long-term follow-up

BackgroundThe prognostic significance of incidental cardiovascular calcifications-including coronary artery calcification (CAC), thoracic aortic calcification (TAC), aortic valve calcification (AVC), and mitral annular calcification (MAC)-detected on non-gated, non-contrast low-dose chest computed tomography (LDCT) remains unclear.PurposeTo evaluate the long-term prognostic significance of incidental cardiovascular calcifications detected on screening LDCT.Material and MethodsThis retrospective cohort study included individuals who underwent LDCT at a single health promotion center between 2007 and 2013. A cardiovascular radiologist quantified CAC, TAC, AVC, and MAC using dedicated software. Multivariable Cox proportional hazards regression was used to assess associations with all-cause mortality (ACM) and major adverse cardiovascular events (MACE), defined as revascularization, myocardial infarction, stroke, or cardiovascular death. Incremental prognostic performance was evaluated using Harrell's concordance index (C-index).ResultsAmong the 2434 included individuals (1863 men; median age = 54.2 years), CAC, TAC, AVC, and MAC were identified in 506 (20.8%), 1215 (49.9%), 159 (6.5%), and 49 (2.0%), respectively. The highest TAC category (≥1000) showed the strongest association with ACM (hazard ratio [HR] = 3.11, 95% confidence interval [CI] = 1.57-6.16; P = 0.001). The highest CAC category (≥400) showed the strongest association with MACE (HR = 8.67, 95% CI = 4.46-16.88; P <0.001). However, a combined model incorporating CAC, TAC, AVC, and MAC did not provide significant incremental prognostic value beyond CAC alone for ACM or MACE.ConclusionIncidental TAC was associated with increased long-term risk of ACM, while CAC was associated with MACE. However, their combined incorporation did not provide significant incremental prognostic value.