[Differences in pharmacologic treatment after acute myocardial infarction. The role of treatment effectiveness]

Despite growing interest concerning the prescription of different drugs in different clinical settings, no explanatory variables have been determined. The aim of this study was to verify if there are any differences in drug prescription at the time of hospital release following myocardial infarction and if any of these differences can be explained by scientific evidence concerning treatment efficacy.

All drugs prescribed to 430 patients discharged from three different cardiology departments after acute myocardial infarction were analyzed. Based on current scientific evidence, it has been, ascertained that aspirin, beta-blockers and ACE-inhibitors can be prescribed unless contraindicate whereas anticoagulants, nitrates and calcium antagonists should be prescribed only in specific clinical conditions. The odd ratio of prescription of each drug among the three cardiology departments was calculated and adjusted for any clinical and test result variables that can specifically affect drug prescription.

Different clinical characteristics of the patients discharged from the three cardiology departments are the following: mean age ranges from 60 to 66 years (p < 0.001), the incidence of non-Q myocardial infarction ranges from 23 to 45% (p < 0.001), post infarction angina ranges from 6 to 15% (p = 0.016), left ventricular failure ranges from 6 to 13% (p = 0.003) and arrhythmia ranges from 5 to 18% (p = 0.007). The adjusted odd ratio for clinical and test results variables showed that prescriptions were similar for ACE-inhibitors (odd ratio 1.3; 95% confidence interval from 0.6 to 3.2), aspirin (OR 2.2; 95% confidence interval from 0.8 to 5.5), beta-blockers (OR 2.2, 95% confidence interval from 0.9 to 5.5) and oral anticoagulants (1.6; 95% confidence interval from 0.6 to 4.5). Instead, there is a statistically significant difference in the prescription of nitrates (OR 4.4; 95% confidence interval from 1.6 to 12.3) and of calcium antagonists (OR 5.4%, 95% confidence interval from 1.0 to 12.5).

Evidence based drug efficacy after acute myocardial infarction seems to establish a uniform pattern of drug prescription in different cardiology departments.