title: Basal and ischemia-induced transcardiac troponin release into the coronary circulation in patients with suspected coronary artery disease.
abstract: 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.
  
  
  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 (25(th), 75(th) 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). Male sex, left ventricular hypertrophy determined by echocardiography, T-wave inversion, and CAD correlated with elevated TTR defined as 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Cardiovascular Medicine, Faculty of Life Sciences, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Seigo
authors.initials: S
authors.lastname: Sugiyama
authors.forename: Koichi
authors.initials: K
authors.lastname: Sugamura
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Nozaki
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ohba
authors.forename: Junichi
authors.initials: J
authors.lastname: Matsubara
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nagayoshi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sumida
authors.forename: Eiichi
authors.initials: E
authors.lastname: Akiyama
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuzawa
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sakamaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kimura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umemura
authors.forename: Hisao
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood* / Q000150:complications; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000209:etiology; D012307:Risk Factors; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T; D000109:Acetylcholine
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