Trends in the use of drug therapies in patients with acute myocardial infarction: 1988 to 1992.

OBJECTIVES

In this study, we investigated the use of thrombolytic agents and other cardiac drugs in a national cohort of patients with acute myocardial infarction and assessed the influence of large clinical studies on types of thrombolytic therapy prescribed.

BACKGROUND

Information about usage patterns for these drugs is unavailable, and little is known about the impact of large clinical trials on their use.

METHODS

We conducted a retrospective cohort study of 65,011 patients who were treated for acute myocardial infarction during fiscal years 1988 to 1992 (October 1, 1987 to September 30, 1992) in hospitals participating in the SMS Corporation's on-line data pool.

RESULTS

The overall thrombolysis rate for patients with acute myocardial infarction increased from 11% in fiscal year 1988 to 18% in fiscal year 1990 and has remained approximately at that level since then. In mid-1989, tissue plasminogen activator was used in 90% of the patients receiving thrombolysis, whereas streptokinase was used in only 10%. Since 1991, tissue plasminogen activator has been used in 60% of patients and streptokinase in almost 30%. Much of this change came after presentation and publication of results of the Second Gruppo Italiano per lo Studio Della Sopravvivenza nell'Infarto Miocardico (GISSI-2) and the Third International Study of Infarct Survival (ISIS-3) trials. Over these 5 years, use of beta-adrenergic blocking agents increased steadily, and use of calcium-channel blocking agents declined steadily.

CONCLUSIONS

Current usage rates of thrombolytic therapy are lower than expected, but trends in usage rates for beta-blockers and calcium channel blockers reflect their increasing and decreasing approval, respectively. Presentation and publication of results from the Third International Study of Infarct Survival and the Second Gruppo Italiano per lo Studio Della Sopravvivenza nell'Infarto Miocardico trials appear to have influenced the type of thrombolytic agent prescribed.