Abstract 14226: Basal and Ischemia-Induced Transcardiac Troponin Release into the Coronary Circulation in Patients with Suspected Coronary Artery Disease
Background Cardiac troponin is a specific biomarker for cardiomyocyte necrosis in acute coronary syndromes. Troponin release from the coronary circulation remains to be determined because of the lower sensitivity of the conventional assay. We sought to determine basal and angina-induced troponin release using a highly sensitive troponin assay.
Methods and Results The cardiac troponin T levels in serum sampled from the peripheral vein (PV), the aortic root (AO), and the coronary sinus (CS) were measured in 105 consecutive stable patients with coronary risk factor(s) and suspected coronary artery disease (CAD) and in 33 patients without CAD who underwent an acetylcholine provocation test. At baseline, there was a significant increase in the troponin levels from AO [9.0 (6.4, 13.1) pg/mL for median (25th, 75th percentiles)] to CS [10.3 (7.3, 15.5) pg/mL, p<0.001] in 96 (91.4%) patients and the difference was 1.1 (0.4, 2.1) pg/mL, which reflected basal transcardiac troponin release (TTR). TTR was positively correlated with PV levels (r=0.22, p=0.03). TTR was significantly higher in men, and in patients with dyslipidemia, lower left ventricular ejection fraction (defined as <50%), negative T waves, CAD, or heart failure. TTR was comparable between patients regardless of age (above/equal to or below 65 years), body mass index (above/equal to or below 25 kg/m2), hypertension, diabetes, lower estimated glomerular filtration rate (above/equal to or below 60 mL/min/1.73 m2), and left ventricular hypertrophy. Multivariate forward logistic regression analyses revealed that male sex (odds ratio (OR): 4.84, 95% confidence interval (CI): 2.02-11.62, p<0.001) and the presence of heart failure (OR: 4.34, 95% CI: 1.36-13.79, p=0.01) were independently associated with elevated TTR (above median: 1.1 pg/mL). A significant increase in TTR was noted in 17 patients with coronary spasms [0.6 (0.2, 1.2) pg/mL, p<0.01] but not in 16 patients without spasms [0.0 (−0.5, 0.9) pg/mL, p=0.73] after the acetylcholine provocation.
Conclusion Basal TTR in the coronary circulation was observed in most of the patients with suspected CAD and risk factor(s). This sensitive assay detected myocardial ischemia-induced increases in TTR caused by coronary spasms.
- © 2012 by American Heart Association, Inc.