Cardiac troponin

Cardiac troponin (abbreviation: cT , often simply: troponin ) is a protein complex that is released into the blood from the muscle cells of the heart when damaged (e.g. during a heart attack ). The detection of an increased troponin level in the blood can indicate a heart muscle damage and can be an indication of a heart attack even with a normal EKG. cT is one of three troponins .

Subunits

protein	Gene name	AA	UniProt	comment
cTNT	TNNT2	298	P45379	Tropomyosin binding subunit; 10 isoforms, mainly P45379-6 in the adult heart, P45379-7 in disease; Path .: Hypertrophic cardiomyopathy (CMH2), dilated cardiomyopathy (CMD1D), restrictive cardiomyopathy (RCM3)
cTNI	TNNI3	210	P19439	Inhibitory subunit; Path .: Hypertrophic cardiomyopathy (CMH7), restrictive cardiomyopathy (RCM1), dilated cardiomyopathy (CMD2A)
TNC	TNNC1	161	P63316	Calcium binding subunit; Path .: Dilated cardiomyopathy (CMD1Z), hypertrophic cardiomyopathy (CMH13)

Laboratory chemistry

Cardiac troponin is a protein complex from the troponin group . It consists of the three subunits cT, cI and C (T = tropomyosin- binding, I = inhibitory , C = calcium- binding), of which cT and cI are specifically expressed in the heart muscle. The detection of the two subunits is therefore used for diagnostic purposes. For using immunoassays . The normal range is below 0.1 ng / ml . The increase in the blood serum can be detected about three hours after the start of the infarction, reaches its maximum after about 20 hours and returns to normal after one to two weeks; in infarcts that do not affect the entire thickness of the myocardial wall ( NSTEMI ) after 48–72 hours . Less specific parameters for heart muscle damage are myoglobin , creatine kinase , GOT and LDH . Creatine kinase also increases much more slowly.

Clinical significance

Troponin test

The height of the maximum troponin level correlates with the survival rate after the heart attack. In addition, it could be shown that the troponin level allows an estimation of the size of the infarct measured against the myocardial necrosis.

Troponin T and I are highly significant for cardiac events, so that they serve as the most important laboratory parameter for acute coronary syndrome . In addition to a heart attack, other cardiac and non-cardiac diseases can be considered as causes in the differential diagnosis.

(→ Main article heart attack, section diagnostics)

history

As early as 1979, the German professor Hugo A. Katus began developing the first sensitive blood tests at the Harvard Medical School in Boston and finally found the protein troponin T at the Heidelberg University Hospital . Together with the Boehringer Mannheim company (now Roche Diagnostics ), he optimized them Measurement method so that this rapid test can be used worldwide today. In large multicenter studies, Katus et al. a. prove that the troponin T measurement is more sensitive and more accurate for heart attack diagnosis than the enzyme measurements of the time. Based on these results, the test has been declared the gold standard for infarct diagnostics by cardiological specialist societies in Europe and the USA.

Literature and Sources

W. Rottbauer, T. Greten, M. Müller-Bardoff, A. Remppis, J. Zehelein, E. Grünig, HA Katus: Troponin T: a diagnostic marker for myocardial infarction and minor cardiac cell damage. In: Eur Heart J . 17, 1996, pp. 3-8.

Individual evidence

↑ ^a ^b ^c ^d German Society for Cardiology: Commentary on the guidelines of the European Society of Cardiology (ESC) for the diagnosis and treatment of acute coronary syndrome without ST segment elevation (NSTE-ACS) . In: cardiologist . tape 3 , no. 2 , p. 81-100 , doi : 10.1007 / s12181-009-0177-2 .
↑ Mewis, Riessen, Spyridopoulos (ed.): Cardiology compact - Everything for ward and specialist examination . 2nd Edition. Thieme, Stuttgart / New York 2006, ISBN 3-13-130742-0 , pp. 169 .
↑ A. Kirchgatterer: The cardiac troponins: is the importance overestimated? A critical analysis of clinical relevance. In: Journal of Cardiology. 5 (6), 1998, p. 292. (pdf; 821 kB)
^ E. Haber, HA Katus, JG Hurrell et al.: Detection and quantification of myocardial cell death: application of monoclonal antibodies specific for cardiac myosin . In: Journal of Molecular and Cellular Cardiology . 14 Suppl 3, September 1982, p. 139-146 , PMID 6183437 .
^ HA Katus, KW Diederich, M. Uellner, A. Remppis, G. Schuler, W. Kübler: Myosin light chains release in acute myocardial infarction: non-invasive estimation of infarct size . In: Cardiovascular Research . tape 22 , no. 7 , July 1988, p. 456-463 , PMID 3252969 .

[ESC-1] German Society for Cardiology: Commentary on the guidelines of the European Society of Cardiology (ESC) for the diagnosis and treatment of acute coronary syndrome without ST segment elevation (NSTE-ACS) . In: cardiologist . tape 3 , no. 2 , p. 81-100 , doi : 10.1007 / s12181-009-0177-2 .

[Mewis-2] Mewis, Riessen, Spyridopoulos (ed.): Cardiology compact - Everything for ward and specialist examination . 2nd Edition. Thieme, Stuttgart / New York 2006, ISBN 3-13-130742-0 , pp. 169 .

[troponin-3] A. Kirchgatterer: The cardiac troponins: is the importance overestimated? A critical analysis of clinical relevance. In: Journal of Cardiology. 5 (6), 1998, p. 292. (pdf; 821 kB)

[4] E. Haber, HA Katus, JG Hurrell et al.: Detection and quantification of myocardial cell death: application of monoclonal antibodies specific for cardiac myosin . In: Journal of Molecular and Cellular Cardiology . 14 Suppl 3, September 1982, p. 139-146 , PMID 6183437 .

[5] HA Katus, KW Diederich, M. Uellner, A. Remppis, G. Schuler, W. Kübler: Myosin light chains release in acute myocardial infarction: non-invasive estimation of infarct size . In: Cardiovascular Research . tape 22 , no. 7 , July 1988, p. 456-463 , PMID 3252969 .