Troponin T better than standard enzymes for estimating extent of myocardial infarct

One measurement of the protein troponin T 72 hours after the start of chest pain is better than using standard enzyme tests to estimate the extent of tissue damage following heart attack, concludes German research.

Creatine kinase, CK-MB, and lactate dehydrogenase require serial sampling to identify peak or cumulative serum concentrations and depend on coronary reperfusion. Furthermore, these enzymes are not exclusive to the myocardium and increases could indicate causes other than myocardial cell damage.

Enzyme activities and serum troponin T were measured after the start of chest pain in 37 patients with a first time heart attack. Blood samples were drawn every four hours on day 1, every eight hours on days 2 and 3, and then once daily until day 10. All but 14 (group 1) had early coronary reperfusion (group 2). Quantitative single photon emission computed tomography thallium-201 scintigraphy was performed at rest two to three weeks after symptoms had begun.

Troponin T concentrations peaked briefly within the first 24 hours, and then again on days 3 to 4 in both groups. The extent of irreversible myocardial damage, indicated by scintigraphy, was accurately reflected in troponin T concentrations taken 72 hours after the start of symptoms in both groups.

The authors conclude that a single measurement of troponin T, taken 72 hours after the start of chest pain, is simple, reliable, and better than enzyme methods.