Epicardial Adipose Tissue Is Associated with Plaque Burden and Composition and Provides Incremental Value for the Prediction of Cardiac Outcome. A Clinical Cardiac Computed Tomography Angiography Study.

OBJECTIVES: We sought to investigate the association of epicardial adipose tissue (eCAT) volume with plaque burden, circulating biomarkers and cardiac outcomes in patients with intermediate risk for coronary artery disease (CAD). METHODS AND RESULTS: 177 consecutive outpatients at intermediate risk for CAD and completed biomarker analysis including high-sensitive Troponin T (hs-TnT) and hs-CRP underwent 256-slice cardiac computed tomography angiography (CCTA) between June 2008 and October 2011. Patients with lumen narrowing ≥50% exhibited significantly higher eCAT volume than patients without any CAD or lumen narrowing <50% (median (interquartile range, IQR): 108 (73-167) cm3 vs. 119 (82-196) cm3, p = 0.04). Multivariate regression analysis demonstrated an independent association eCAT volume with plaque burden by number of lesions (R2 = 0.22, rpartial = 0.29, p = 0.026) and CAD severity by lumen narrowing (R2 = 0.22, rpartial = 0.23, p = 0.038) after adjustment for age, diabetes mellitus, hyperlidipemia, body-mass-index (BMI), hs-CRP and hs-TnT. Univariate Cox proportional hazards regression analysis identified a significant association for both increased eCAT volume and maximal lumen narrowing with all cardiac events. Multivariate Cox proportional hazards regression analysis revealed an independent association of increased eCAT volume with all cardiac events after adjustment for age, >3 risk factors, presence of CAD, hs-CRP and hs-TnT. CONCLUSION: Epicardial adipose tissue volume is independently associated with plaque burden and maximum luminal narrowing by CCTA and may serve as an independent predictor for cardiac outcomes in patients at intermediate risk for CAD.

Combined Assessment of High-Sensitivity Troponin T and Noninvasive Coronary Plaque Composition for the Prediction of Cardiac Outcomes.

PURPOSE: To determine the risk-stratification ability of plaque volume and composition assessment with cardiac computed tomographic (CT) angiography and high-sensitivity troponin T (hsTnT) in patients at intermediate risk for coronary artery disease (CAD). MATERIALS AND METHODS: The study complied with the Declaration of Helsinki and was approved by the local ethics committee. All patients gave written informed consent. Five hundred twenty-one consecutive patients (mean age ± standard deviation, 62 years ± 10; 256 men and 265 women) were included in this prospective, observational, longitudinal, single-center study. Quantitative cardiac CT angiography analysis was performed in all patients (for 7690 coronary segments), whereas biomarkers (hsTnT and high-sensitivity C-reactive protein) were available in 408 patients (78%). To evaluate the incremental value of cardiac CT angiography and hsTnT for the prediction of cardiovascular events, multivariate Cox regression and integrated discrimination improvement analysis were applied. RESULTS: In 521 patients, 13 hard cardiac events occurred during a mean follow-up period of 2.3 years ± 1.1 (median, 2.4 years; range, 0.5-4.5 years), while 23 patients underwent late coronary revascularization. The Duke clinical score was 51% ± 30, indicating intermediate risk. The presence of no plaques or purely calcified versus noncalcified plaques, plaque volume according to tertiles, and increased hsTnT (≥14 pg/mL) was independently associated with hard cardiac events (hazard ratio [HR] = 26.08, 95% confidence interval [CI]: 2.78, 244.99; HR = 12.14, 95% CI: 1.87, 78.74; and HR = 10.31, 95% CI: 2.72, 39.0, respectively; P < .01 for all). Patients with increased hsTnT and plaque burden (n = 53) showed the highest incidence for hard cardiac events (annual rate, 12.7%), followed by those with either increased hsTnT or plaque burden (n = 145; annual rate = 0.44%, P < .03), while those with lower hsTnT and plaque burden exhibited excellent outcomes and no hard event during the follow-up duration (n = 210; annual rate = 0%, P < .001). CONCLUSION: Use of hsTnT as a marker of myocardial microinjury and cardiac CT angiography as a marker of the total atherosclerotic burden improves the prediction of cardiac outcome in patients with presumably stable CAD and may aid in personalized risk stratification in patients at intermediate risk.