Beyond medication prescription as performance measures: optimal secondary prevention medication dosing after acute myocardial infarction

Abstract

Objectives: The aim of this study was to examine the prescribing patterns of medications quantified by the performance measures for acute myocardial infarction (AMI).

Background: Current performance measures for AMI are designed to improve quality by quantifying the use of evidence-based treatments. However, these measures only assess medication prescription. Whether patients receive optimal dosing of secondary prevention medications at the time of and after discharge after AMI is unknown.

Methods: We assessed treatment doses of beta-blockers, statins, and angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARBs) at discharge and 12 months after AMI among 6,748 patients from 31 hospitals enrolled in 2 U.S. registries (2003 to 2008). Prescribed doses were categorized as none, low (<50% target [defined from seminal clinical trials]), moderate (50% to 74% target), or goal (≥ 75% target). Patients with contraindications were excluded from analyses for that medication.

Results: Most eligible patients (>87%) were prescribed some dose of each medication at discharge, although only 1 in 3 patients were prescribed these medications at goal doses. Of patients not discharged on goal doses, up-titration during follow-up occurred infrequently (approximately 25% of patients for each medication). At 12 months, goal doses of beta-blockers, statins, and ACEI/ARBs were achieved in only 12%, 26%, and 32% of eligible patients, respectively. After multivariable adjustment, prescription of goal dose at discharge was strongly associated with being at goal dose at follow-up: beta-blockers, adjusted odds ratio (OR): 6.08 (95% confidence interval [CI]: 3.70 to 10.01); statins, adjusted OR: 8.22 (95% CI: 6.20 to 10.90); ACEI/ARBs, adjusted OR: 5.80 (95% CI: 2.56 to 13.16); p < 0.001 for each.

Conclusions: Although nearly all patients after an AMI are discharged on appropriate secondary prevention medications, dose increases occur infrequently, and most patients are prescribed doses below those with proven efficacy in clinical trials. Integration of dose intensity into performance measures might help improve the use of optimal medical therapy after AMI.

Keywords: ACEI; AMI; ARB; CI; LDL-C; LV; OR; SBP; acute myocardial infarction; angiotensin II receptor blocker; angiotensin-converting enzyme inhibitor; confidence interval; left ventricular; low-density lipoprotein cholesterol; myocardial infarction; odds ratio; performance measures; secondary prevention; systolic blood pressure.

Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Flowchart of Patients

*indicates patients who reported taking zero medications, patients who were taking medications not FDA-approved for patients after myocardial infarction or with concurrent heart failure, or patients with doses that were unknown. CI, contraindications

Figure 2. Frequency of dose categories for beta blockers, statins, and ACE/ARBs after acute myocardial infarction. Panel A displays dose categories at hospital discharge. Panel B displays dose categories at follow-up

Figure 3. Systolic Blood Pressure at Discharge by Dose Category

ACE/ARB, angiotensin converting enzyme inhibitors/angiotensin II receptor blockers

Figure 4. Outpatient Follow-up Intensity

Frequency of follow-up for patients who did and who did not achieve goal dose at follow-up