Changes in drug treatment and case fatality of patients with acute myocardial infarction

OBJECTIVE: To describe changes in medications administered to patients with acute myocardial infarction between 1984/1985 and 1988/1990 and changes in case fatality. DESIGN: Descriptive study from the Newcastle MONICA Project, which monitors all heart attacks in men and women aged 25 to 69 years in the Lower Hunter Region of New South Wales. SUBJECTS: All patients admitted to hospital with a "definite" acute myocardial infarction who survived at least 28 days during periods in 1984/1985 (513 events) and 1988/1990 (790 events). MAIN OUTCOME MEASURES: Changes in drugs being taken immediately before the onset of the myocardial infarction, prescribed during hospitalisation and on discharge from hospital, and changes in case fatality rates. RESULTS: From the first time period to the second there were significant increases in the use of aspirin, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors and hypolipidaemic agents, and significant reductions in the use of diuretics. In 1988/1990, 34% of patients with a definite myocardial infarction received thrombolytic therapy compared with fewer than 1% in 1984/1985. Among those patients who survived at least one hour from onset of symptoms, the case fatality rate declined from 13.5% to 7.9% (change -5.6%; 95% confidence limits, -8.9%, -2.2%). CONCLUSION: Large changes in drug treatment of patients with acute myocardial infarction have occurred in the second half of the 1980s. These may be responsible for the reduction in case fatality. Nevertheless, use of drugs of proven effectiveness in acute care and for secondary prevention is surprisingly low in this population.