[Early peak activity of creatine kinase in non-thrombolysed myocardial infarction: prognostic factor?].

The time elapsed between the onset of pain and serum creatine kinase (CK) peak activity is an indirect marker of reperfusion in the thrombolytic treatment of myocardial infarction, and some authors regard this time as a prognostic factor in infarctions not treated with thrombolysis. CK activity was measured in 90 consecutive patients (mean age 66.9 +/- 13.7 years) with acute myocardial infarction (anginal pain + ECG signs + CK greater than 160 3U/l, including 40 p. 100 of CK MB). Measurements began at the time of admission to the intensive care unit and were repeated 6-hourly until CK levels returned to normal. Mean time of CK peak activity was 19.30 +/- 7.15 h after the initial pain (8 to 55 hours prior to admission). This time was not influenced by age, sex, presence or absence of risk factors and history of coronary disease, nor by the anterior or transmural location of the infarct. In contrast, an early arrival at the intensive care unit was associated with an early CK peak: patients who reached the unit within 6 hours or less had a peak at 18.15 +/- 6 h, whereas those who arrived after 6 h had a peak at 22.30 +/- 9.30 h (p less than 0.01). In addition, cases of infarction without Q wave and with an initially elevated ST segment had an earlier peak than the others (16.30 +/- 5.30 h vs 19 +/- 6.45 h in transmural infarctions and vs 24.30 +/- 7.30 h in infarctions with initially depressed ST; p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)