5196Coronary artery calcification predicts MACE and all-cause mortality in individuals undergoing non-cardiac computed tomography for non-cardiovascular indications

Abstract

Abstract Introduction Coronary artery calcification (CAC) measured on ECG-gated cardiac CT is a strong predictor of cardiovascular (CV) risk in asymptomatic individuals in a primary prevention setting. However, the prognostic value of CAC in an unselected population referred for non-gated non-cardiac chest CT (NCCT) is unknown. Purpose To determine whether CAC predicts major adverse cardiovascular events (MACE) and all-cause mortality in patients referred for NCCT for non-CV indications. Methods A random sample of 741 individuals, without prior known history of coronary artery disease (CAD) who underwent NCCT for non-CV indications at a tertiary care hospital in 2008 were included in this study. NCCT was assessed qualitatively for the presence and extent of CAC by two experienced physicians. Data abstraction was performed by electronic medical record (EMR) review. Our primary endpoint of MACE, defined as CV mortality, MI, PCI, CABG, heart failure and stroke as well as secondary endpoint of all-cause mortality, over a median follow up of 8 (IQR 4–10) years, was adjudicated per independent review. Results Among 741 individuals (mean age 61.1±15.5 years, 60% female, 91% Caucasian), 57% were hypertensive, 30% had hyperlipidemia, 14% were diabetic and the mean ASCVD score was 12.2±11.6. CAC was present in 425/741 (57.4%) individuals. Among those with CAC, it was mild in 172/425 (40%), moderate in 143/425 (34%) and severe in 110/425 (26%) individuals. Overall, MACE occurred in 115/741 (15.5%) patients. Compared to those without MACE, CAC was more prevalent (83% vs. 53%, p<0.001) and extensive (at least moderate: 67% vs. 28%, p<0.001) in those with MACE. Over a median follow up of 8 (IQR 3–10) years, the presence of any CAC was associated with a 4-fold higher risk of MACE (HR 4.22, 95% CI (1.4–8.9), p<0.001), after adjustment for age and gender. On stratification, severe CAC had a near 9-fold increased risk of MACE (HR 8.8, 95% CI (5.1–15.2), p<0.001), followed by moderate CAC with a near 6-fold increased risk of MACE (HR 5.7, 95% CI (2.8–9.8), p<0.001), and a near doubling of MACE risk with mild CAC (HR 1.99, 95% CI (1.1–4.3), p=0.034). Similar results were observed with all-cause mortality (Figure 1). Conclusions CAC is an independent predictor of MACE and all-cause mortality in an unselected patient population referred for NCCT for non-CV indications, which may provide an opportunity to improve population health without the need for additional imaging. Acknowledgement/Funding Dr. Banerji and Dr. Alvi were supported by NIH/NHLBI 5T32HL076136.