Effect of age on the use of evidence-based therapies for acute myocardial infarction

Background — Previous studies have documented an underuse of evidence-based therapies in patients with acute myocardial infarction (AMI). However, many of these studies failed to consider contraindications to therapy, the effect of age (ie, elderly vs non-elderly patients) on use, or both. The objective of this study was to determine whether elderly patients are less likely than non-elderly patients to receive evidence-based AMI treatments, both before and after the consideration of contraindications to therapy.

Methods — A retrospective chart review of a random sample of 5131 patients with AMI who were admitted to 1 of 44 hospitals in Ontario was conducted for the fiscal years 1994 to1996. Using the Canadian Cardiovascular Research Team (CCORT)/Canadian Cardiovascular Society (CCS) Quality Indicators for AMI Care, we classified patients as being eligible or ideal (ie, no contraindications to treatment) candidates to receive aspirin, β-blockers, thrombolysis, angiotensin-converting enzyme inhibitors (ACEIs), or statins or to undergo lipid profiling. The proportions of eligible and ideal patients who received treatment were calculated, and the latter were compared with benchmarks.

Results — The median age of the cohort was 69 years; 63% were of the patients were aged ≥65 years. There was underperformance of prescribing treatments in ideal candidates relative to benchmarks (eg, aspirin at discharge: 78.6% vs 90% benchmark). The odds of ideal (ie, no contraindications) elderly candidates receiving various evidence-based AMI treatments were consistently less than that of non-elderly patients with AMI, with the exception of ACEIs at discharge (odds ratio, 1.46; 95% CI, 1.22–1.74).

Conclusions — Despite adjustments for contraindications to therapy, the underuse of AMI treatments, particularly in elderly patients, was found.