The American journal of cardiology
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Randomized Controlled Trial Clinical Trial
Metoprolol in acute myocardial infarction. Enzymatic estimation of infarct size. The MIAMI Trial Research Group.
The maximum serum activity for aspartate aminotransferase (s-ASAT) during the first 3 days was recorded in 5,507 patients with suspected or definite acute myocardial infarction. The s-ASAT activity was corrected for the normal range from each center. ⋯ Univariate analyses indicated that the delay time between onset of symptoms and randomization and sympathetic activity at entry significantly influenced the effect of metoprolol. A similar decrease in serum enzyme activity after metoprolol treatment was observed independent of signs of infarct localization on the entry electrocardiogram.
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Randomized Controlled Trial Clinical Trial
Metoprolol in acute myocardial infarction. Arrhythmias. The MIAMI Trial Research Group.
Forty-five patients in the placebo (1.5%) and 29 in the metoprolol (1%) groups, respectively, were receiving antiarrhythmic drugs on a long-term basis before entry into the trial. Before randomization, 2.2% (n = 64) of the placebo and 1.7% (n = 50) of the metoprolol patients developed ventricular fibrillation (VF) in the hospital. The corresponding figures for atrial fibrillation or flutter were 3% (n = 87) and 3.3% (n = 94). ⋯ Although antiarrhythmic drugs were intended to be given only for major ventricular tachyarrhythmias a large proportion of patients received such treatment. Significantly more patients were treated with antiarrhythmics in the placebo (21.5%) than in the metoprolol group (19.2%, p = 0.03) during the study period, but predominantly during the first 5 days. Atrial fibrillation or flutter and other supraventricular tachyarrhythmias were significantly less frequent in the metoprolol than in the placebo group, as was the use of cardiac glycosides.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Metoprolol in acute myocardial infarction. Development of myocardial infarction. The MIAMI Trial Research Group.
The effect of metoprolol on the development of an acute myocardial infarction (AMI) during days 0 to 3 and on late first and recurrent infarctions during days 4 to 15 has been investigated. Signs on electrocardiogram (ECG) were well balanced between the treatment groups at entry; 70% of patients had signs of suspected AMI and 19% of patients had normal ECGs. The remaining patients had abnormal ECGs but actual infarction could not be localized. ⋯ No difference in the effect of metoprolol regarding localization of the early AMI was observed. Late first myocardial infarction development (days 4 to 15) was observed in 20 patients (0.7%) in each group. Recurrent myocardial infarction tended to develop more frequently during days 4 to 15 in the placebo group compared with the metoprolol group (3.9% vs 3.0%, p = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)
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Comparative Study Clinical Trial
Metoprolol in acute myocardial infarction. Narcotic analgesics and other antianginal drugs. The MIAMI Trial Research Group.
The effect of metoprolol on chest pain has been assessed in terms of the duration and the use of narcotic analgesics, nitrates and calcium-channel blockers. Fewer metoprolol-treated patients in the MIAMI trial were given narcotic analgesics (49% of the placebo patients vs 44% of the metoprolol patients, p less than 0.001), nitrates (55% vs 53%, p = 0.10) and calcium-channel blockers (12% vs 9%, p less than 0.001). A total number of 6,697 dose equivalents of narcotic analgesics were given to the placebo group compared with 5,493 dose equivalents to the metoprolol group, a difference of 18% (p less than 0.001). ⋯ A multivariate analysis disclosed that site of suspected infarction, delay time, entry systolic blood pressure and metoprolol treatment all had a significant effect on the use of narcotic analgesics. There was a nonsignificant tendency for heart rate to be of importance. In the placebo group the use of narcotic analgesics increased with decreasing delay time and increasing systolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Metoprolol in acute myocardial infarction. Mortality. The MIAMI Trial Research Group.
After 15 days there were 142 deaths in the placebo group (4.9%) and 123 deaths in the metoprolol group (4.3%), a difference of 13% (p = 0.29). The 95% confidence limits for the relative effect of metoprolol ranged from an 8% excess (-8%) to a 33% reduction (+33%) in mortality. There was generally a lower mortality rate for metoprolol-treated patients in most subgroups and a consistent tendency for a more pronounced difference between the treatment groups in those subgroups with a placebo mortality rate higher than the average for all placebo patients. ⋯ Using a simple model, the placebo mortality was found to increase with increasing number of 8 risk predictors defined from prestudy experience, from 0% in patients with no risk predictors to 11.6% in patients with any 5 or more of these risk factors. Similarly, there was an increase in the difference between the treatment groups in favor of metoprolol with increasing number of placebo risk factors. Metoprolol had no apparent effect in a low-mortality risk group (less than or equal to 2 risk factors), but there was a difference in mortality of 29% in favor of metoprolol in a high-risk group (greater than or equal to 3 risk factors) comprising one-third of the trial population.(ABSTRACT TRUNCATED AT 250 WORDS)