Complexity of enzyme release during acute myocardial infarction in a controlled study with early nifedipine treatment.
Fifty-seven consecutive patients with acute myocardial infarction (AMI), admitted to a coronary care unit (CCU) within 6 h from onset of symptoms were included in the study and randomly allocated to nifedipine treatment or placebo. The 23 patients in the treatment group received 10 mg nifedipine orally at the onset of the study, after 30 min, and then every 6 h. Placebo was given to the 34 patients in the control group. The study was double blind. Serum time-activity curves for creatine-kinase-MB (CK-MB) and myoglobin (MG) were established from frequent determinations. The two patient groups did not differ significantly regarding average cumulative MG and CK-MB release. In both groups the range was wide, with the largest maximal individual release about 30 times larger than the smallest. In most patients the enzyme release occurred stepwise, resulting in two or more separate peaks. In the treatment group significantly fewer patients had multiple peaks of MG (P less than 0.05) and CK-MB (P less than 0.025) release. The initial peaks had a longer duration in the treatment group and total release tended to stop earlier. In the control group a highly significant correlation between cumulative MG and CK-MB release was obtained, while in the treatment group no such correlation was observed. In conclusion, oral administration of nifedipine during acute myocardial infarction appears to influence the pattern of enzyme release, although no effect on the total cumulative release could be demonstrated.
D000368:Aged; D002986:Clinical Trials as Topic; D003402:Creatine Kinase / Q000097:blood*; D004311:Double-Blind Method; D006801:Humans; D007527:Isoenzymes; D007700:Kinetics; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000201:enzymology; D009211:Myoglobin / Q000097:blood*; D009543:Nifedipine / Q000627:therapeutic use*
D007527:Isoenzymes; D009211:Myoglobin; D003402:Creatine Kinase; D009543:Nifedipine