Use of secondary prevention pharmacotherapy after first myocardial infarction in patients with diabetes mellitus

Abstract

Background: Despite recommended pharmacotherapies the use of secondary prevention therapy after myocardial infarction (MI) remains suboptimal. Patients with diabetes mellitus (DM) have worse prognosis after MI compared to patients without DM and aggressive secondary prevention pharmacotherapy in this population is therefore warranted. We examined the changes in use of evidence-based secondary prevention pharmacotherapy in patients with and without DM discharged after first MI.

Methods: All patients aged 30 years or older admitted with first MI in Denmark during 1997-2006 were identified by individual-level linkage of nationwide registries of hospitalizations. Univariate and multivariate logistic regression models were used to identify patient characteristics associated with initiation of acetylsalicylic acid, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, β-blockers, and clopidogrel within 90 days, and statins within 180 days of discharge, respectively.

Results: A total of 78,230 patients were included, the mean age was 68.3 years (SD 13.0), 63.5% were men and 9,797 (12.5%) had diabetes. Comparison of claimed prescriptions in the period 1997-2002 and 2003-2006 showed significant (p < 0.001) increases in claims for acetylsalicylic acid (38.9% vs. 69.7%), angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (38.7% vs. 50.4%), β-blockers (69.2% vs. 77.9%), clopidogrel (16.7% vs. 66.3%), and statins (41.3% vs. 77.3%). During 2003-2006, patients with DM claimed significantly less acetylsalicylic acid (odds ratio [OR] 0.81 [95% confidence interval [CI] 0.74-0.88) and clopidogrel (OR 0.91 [95% CI 0.83-1.00]) than patients without DM.

Conclusions: Despite sizeable increase in use of evidence-based secondary prevention pharmacotherapy after MI from 1997 to 2006, these drugs are not used in a substantial proportion of subjects and patients with DM received significantly less antiplatelet therapy than patients without DM. Increased focus on initiation of secondary prevention pharmacotherapy after MI is warranted, especially in patients with DM.

Figure 1

The selection of patients aged ≥30 years and alive 30 days after first myocardial infarction admitted to a Danish hospital during 1 January 1997–31 December 2006.

Figure 2

Multivariable logistic regression analyses showing odds ratios for claiming secondary prevention therapy after first myocardial infarction during 2003–2006 for acetylsalicylic acid (ASA), angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers (ACEIs/ARBs), β-blockers, clopidogrel, and statins. DM: diabetes mellitus. Analyses were adjusted for age, gender, comorbidity, and concomitant pharmacotherapy.

Figure 3

Use of secondary prevention drugs after first myocardial infarction in combinations of two, three, four or five agents including acetylsalicylic acid, angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers, β-blockers, clopidogrel, and statins, respectively, claimed ≤90 days after discharge during the period 2003–2006. DM: diabetes mellitus.