The American journal of cardiology
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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. Patients and methods. The MIAMI Trial Research Group.
The effects of early intervention with metoprolol in patients with suspected or definite acute myocardial infarction (AMI) have been assessed in a randomized, double-blind, placebo-controlled international study. Patients aged 75 years or younger were eligible for entry if they presented to a coronary care unit within 24 hours of the onset of symptoms of an AMI. Exclusion criteria included current treatment with a beta blocker or calcium-channel blocker, heart rate less than or equal to 65 beats/min, systolic blood pressure less than or equal to 105 mm Hg, contraindications and other administrative reasons. ⋯ The study period was 15 days in addition to the day of randomization. The patients' clinical history and status at entry were documented. The following outcome variables were recorded: mortality, development of AMI, serum enzyme activity, electrocardiographic signs of AMI, late or recurrent AMI, arrhythmias, treatment of chest pain, concomitant treatment, adverse events and details of treatment with trial medication.
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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)
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Clinical Trial
Metoprolol in acute myocardial infarction. Patient population. The MIAMI Trial Research Group.
During the recruitment phase of the MIAMI trial (December 1982 to March 1984), data on 26,439 patients eligible for inclusion were entered. Of these, 5,778 patients were included. Current treatment with either beta blockers or calcium-channel blockers (51%) was the most predominant reason for exclusion. ⋯ Before randomization 20% of the patients had normal electrocardiograms; 70% could be classified as having electrocardiographic signs of acute myocardial infarction; and 10% presented with other electrocardiographic abnormalities. Electrocardiographic signs at entry suggested a predominance of anterior wall infarctions. The randomized patients were not representative of eligible patients and the treatment groups were well balanced at entry.
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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.