Use of cardiovascular drugs after acute myocardial infarction:: A marked shift towards evidence-based drug therapy

Objective. To investigate the prescription pattern for cardiovascular drugs among patients discharged after an acute myocardial infarction (AMI) in hospitals that had participated in a corresponding study seven years earlier, and examine what the indications were for use of the different drugs. Methods. From 16 hospitals we drew a sample of patients who were discharged with a diagnosis of AMI during a three months period in 1999/2000. Physicians in each hospital obtained from the medical records the observed rate of use of cardiovascular drugs at discharge. The drug use was compared with findings from a corresponding sample drawn in 1993. The main indication for use of the different cardiovascular drugs was recorded for the 1999/2000 sample. Results. 399 patients discharged alive were included in the first study and 767 in the second. The use of beta-blockers, ACE inhibitors and statins rose substantially during the period. For patients aged less than or equal to70 drug use in respectively 1993 and 1999/2000 was as follows: beta-blockers 73% vs 89%, ACE inhibitors 14% vs 29%, statins not recorded vs 82%; corresponding figures for patients aged >70 were: beta-blockers 45% vs 74%, ACE inhibitors 19% vs 38%, statins not recorded vs 35%. Aspirin/anticoagulant use was largely unchanged; 93% and 70% of patients aged less than or equal to70 and >70 respectively used these drugs at the second survey. The use of regular nitrates and calcium antagonists had decreased. Nearly half of the >70 group and one-fifth of persons less than or equal to70 used 5-9 cardiovascular drugs. Conclusion. At the end of the 1990s a substantial shift in drug therapy after AMI occurred, with a markedly increased use of drugs proven to be effective in clinical trials and less use of other cardiovascular drugs. The most frequently reported main indication for use of drugs was secondary prevention. The principles of evidence-based drug therapy became increasingly adopted among clinicians during the 1990s.