Abstract 13612: Association of Tracheobronchial Calcification with Cardiovascular Events and All-cause Mortality in Multi-Ethnic Study of Atherosclerosis (MESA); the MESArthritis Ancillary Study

Introduction: Tracheobronchial calcification (TBC), is a readily available potential biomarker in non-contrast chest CT scans, including cardiac calcium scan CTs. However, there is a paucity in literature investigating how this measure contributes to CVD risk prediction. Hypothesis: TBC is associated with CVD and mortality events independent from CAC score. Methods: Available non-contrast chest CT images from Johns Hopkins Hospital field center within the fifth exam of the MESA cohort (2010-2012) were re-analyzed as part of the MESArthritis ancillary study. The calcifications observed in the wall of tracheobronchial tree were measured from aortic arch to carina, by calcium scoring package (VScore, Vitrea 7.11, Vital Images). Outlier values were excluded using the Interquartile range-based outlier fence estimates. Association of TBC with cardiovascular risk factors was investigated by linear regression models. Cox proportional hazard models were applied for CVD and mortality event prediction by TBC with and without adjustment for age, gender, race, CAC, and Framingham global CVD risk score (FRS). Results: After exclusion of 39 outliers, a total of 382 participants (51.2% female) with a mean age of 69.9 (±8.82) were included. TBC was associated with age (β=3.26, p:.002), gender (β=96.30, p<.001), race (β=-28.96, p:.002), and FRS (β=3.57, p<.001). In time-to-event analysis, risk of CHD, CVD, and mortality increased by 1.34, 1.28, and 1.15-fold respectively, by every 100 increase in TBC score adjusted for age, gender, and race. Compared with CAC score (C-index: 0.78) and FRS (0.71) individually, the model with TBC addition to both scores had higher C-index (0.82) for CHD event prediction. Conclusions: Quantification of calcifications in tracheobronchial area can be used to predict CHD, CVD and all-cause mortality and augment the predictive power of the highly validated CAC and FRS for CHD events.