[The peak of creatine phosphokinase level in the acute phase of myocardial infarction in patients with and without ischemic precedents].

Two hundred and one patients admitted to Coronary Care Unit with documented acute myocardial infarction, whose chest pain had occurred within 12 hours of hospital admission non thrombolised, were studied. The peak of creatine kinase (CK) was examined and compared between patients without previous manifestations of myocardial ischemia (group A, 106 patients) and patients with/history angina pector or healed myocardial infarction (group B, 95 patients). The mean peak creatine kinase level in the negative history group was higher (2261 +/- 226 U/L vs 1779 +/- 97 U/L p < 0.001), especially in patients aged less than 65. No significant difference was observed in patients aged more than 64 of the two groups. Patients with a positive history presented more frequently ischemic complications (p < 0.05) while the frequency of hemodynamic disturbances and arrhythmias was not significantly different. Total mortality was similar in the two groups (22.6% vs 21%) and more frequently occurred in older patients with congestive heart failure. The authors form the hypothesis that the higher mean peak creatine level in patients without previous myocardial ischemia is the result of absence of coronary collateral circulation. The presence of collateral vessels permits less extensive myocardial infarction but it does not change the prognosis.