Relations between digital thermal monitoring of vascular function, the Framingham risk score, and coronary artery calcium score

Background: Digital thermal monitoring (DTM) of vascular function was shown to correlate with the presence of known coronary artery disease (CAD). Objective: We evaluated whether DTM can identify at-risk, asymptomatic patients with significant coronary artery calcium (CAC) or increased Framingham risk score (FRS). Methods: Two hundred thirty-three consecutive asymptomatic subjects (58 ± 11 years; 62% men) without known CAD underwent DTM, CAC, and FRS calculation. DTM measurements were obtained during and after a 5-minute suprasystolic arm-cuff occlusion. After cuff-deflation temperature rebound (TR) and area under the temperature curve (AUC) were measured and correlated with FRS and CAC. Results: TR was lower in patients with FRS > 20% and CAC ≥ 100 as compared with FRS < 10% and CAC < 10, respectively (P < 0.05). After adjustment for age, sex, and traditional cardiac risk factors, the odds ratio of the lowest compared with the upper 2 tertiles of TR was 3.96 for FRS ≥ 20% and 2.37 for CAC ≥ 100 compared with low-risk cohorts. The area under the receiver operating characteristic (ROC) curve to predict CAC ≥ 100 increased significantly from 0.66 for FRS to 0.79 for TR to 0.89 for TR + FRS. Conclusions: Vascular dysfunction measured by DTM strongly correlates with FRS and CAC independent of age, sex, and traditional cardiac risk factors and was superior to FRS for the prediction of significant CAC.