[Troponin T in acute myocardial infarction. Diagnosis and prognosis in patients admitted for suspected acute myocardial infarction]. / Troponin T ved akut myokardieinfarkt. Diagnostik og prognostik hos patienter indlagt til observation for akut myokardieinfarkt.

Cardiac troponin T (TnT) is a new serological marker for use as a diagnostic tool for myocardial damage. A blinded prospective multicentre study representing 298 patients who on admission were suspected of acute myocardial infarction (AMI) to the coronary care units of six Scandinavian hospitals was undertaken to assess the diagnostic performance and prognostic efficacy of a new cardiospecific TnT immunoassay. We used a discriminator value of TnT of 0.20 micrograms/l. One hundred and fifty-five patients (52%) had definite AMI, based on WHO criteria (all had peak S-TnT values > or = 0.20 micrograms/l); 127 patients (43%) had ischaemic heart disease (IHD) without AMI; and 16 patients (5%) had non-IHD (all had peak S-TnT values < 0.20 micrograms/l). The 127 IHD-patients without definite AMI could be subdivided into a group of 44 patients with S-TnT peak values > or = 0.20 micrograms/l, and a group of 83 patients with TnT below this level. A follow-up study was able to define the clinical significance of these findings. The cumulative six months probability of suffering cardiac death or AMI was significantly higher in the subgroup with increased TnT values (14% (6/44)) as compared to the other subgroup (4% (3/83)) (Log-rank test, p = 0.025). The probability of cardiac events was 15% for the patients with definite AMI. We conclude that increased troponin T in serum can detect a subgroup of IHD-patients in whom AMI has been ruled out, but who still have a prognosis as serious as that of patients with definite AMI.

Diagnostic performance and prognostic value of serum troponin T in suspected acute myocardial infarction.

Cardiac troponin T (TnT) is a new serological marker for use as a diagnostic tool for myocardial damage. A blinded prospective multicentre study representing 298 patients suspected of having acute myocardial infarction (AMI), and admitted to the coronary care units of six Scandinavian Hospitals was undertaken to assess the diagnostic performance and prognostic efficacy of a new cardiospecific TnT immunoassay. We used a discriminator TnT value of 0.20 microgram l-1. One hundred and fifty five patients (52%) had definite AMI, based on WHO criteria (all had peak S-TnT values of > or = 0.20 micrograms l-1); 127 patients (43%) had ischaemic heart disease (IHD) without AMI; and 16 patients (5%) had non-IHD (all had peak S-TnT values of < 0.20 microgram l-1). The 127 IHD-patients without definite AMI could be subdivided into a group of 44 patients with S-TnT peak values of > or = 0.20 microgram l-1, and a group of 83 patients with TnT below this level. An equal identification of these patients among the centres was seen (mean +/- SD 35 +/- 13%; range 20-55%). A follow-up study was able to define the clinical significance of these findings. The cumulative 6 months probability of suffering cardiac death or AMI was significantly higher in the subgroup with increased TnT values (14% (6/44)) as compared to the other subgroup (4% (3/83)) (Log-rank test, p = 0.025). The probability of cardiac events was 15% for the patients with definite AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical markers for myocardial infarction used in combination with clinical decision limits. Influence of S-myoglobin on the predictive values.

To predict the development of an acute myocardial infarction (AMI) in a patient with chest pain or other symptoms compatible with myocardial infarction is a difficult clinical problem. In this study of 927 consecutive patients with a suspected AMI symptoms selected by the Multicenter Chest Pain Study Group were tested. An equation was constructed based on five of the most significant variables found. In a subgroup of 305 patients the additional value of S-Myoglobin was tested and found to be valuable for the decision of further handling of the patient with suspected AMI.

Use of biochemical tests for myocardial infarction in the county of Västernorrland, a clinical chemistry routine for the diagnosis of myocardial infarction.

A study of 116 patients admitted on the suspicion of myocardial infarction is presented. Twenty three of the patients were found to have infarction. For the diagnosis of infarct the most reliable biochemical analyses at present appear to be serum creatine kinase (S-CK, E.C.2.7.3.2.) with its isoenzyme S-CKMB and serum lactate dehydrogenase (S-LD, E.C.1.1.1.27.) with its isoenzyme S-LD-1. If an organization with blood samples at fixed intervals after the appearance of symptoms could be arranged, this would be most recommendable. In many hospitals this is, however, difficult and the blood samples have to be drawn at specified hours. In the four hospitals in the county of Västernorrland, Sweden, this latter procedure has been introduced. Blood is drawn at the arrival of the patient, at 8 am and 8 pm the first day, and at 8 am the next two days of the stay in hospital. In the first two samples S-CK and S-LD are determined, in the third S-CK, in the fourth S-CK and S-LD and in the fifth S-CK. If the values are elevated, S-CKMB and S-LD-1 are determined. S-Myoglobin has been found valuable in the early exclusion of the diagnosis of infarction.