Changes in Myocardial Infarction Guideline Adherence as a Function of Patient Risk: An End to Paradoxical Care?
Does use of guideline-based care during hospitalization for a myocardial infarction (MI) vary as a function of patients’ baseline risk, and has there been a temporal improvement in guideline adherence?
A total of 112,848 patients with MI were enrolled at 279 hospitals participating in Get With The Guidelines–Coronary Artery Disease (GWTG-CAD) between August 2000 and December 2008. The authors developed and validated an in-hospital mortality model (C-statistic 0.75) to stratify patients into risk tertiles: low (0-3%), intermediate (3-6.5%), and high (>6.5%). Use of guideline-based care and temporal trends were examined.
About one third of patients were classified as low risk, intermediate risk, and high risk. High-risk patients were more likely to be older, female, and have multiple medical comorbidities. High-risk patients were hospitalized longer (median length of stay, 5 days), were less likely to be discharged home, and were more likely to die during their hospitalization than lower-risk patients. High-risk patients were significantly less likely to receive aspirin, beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers, statins, diabetic treatment, smoking cessation advice, or cardiac rehabilitation referral at discharge compared with those at lower risk (all p < 0.0001). However, use of guideline-recommended therapies increased significantly in all risk groups per year (low-risk odds ratio, 1.33; 95% confidence interval [CI], 1.22-1.45; intermediate-risk odds ratio, 1.30; 95% CI, 1.21-1.38; and high-risk odds ratio, 1.30; 95% confidence interval, 1.23-1.37). Also, there was a narrowing in the guideline adherence gap between low- and high-risk patients over time (p = 0.0002).
Although adherence to guideline-based care remains paradoxically lower in those MI patients at higher risk of mortality and most likely to benefit from treatment, care is improving for eligible patients within all risk categories, and the gaps between low- and high-risk groups seem to be narrowing.
Among the explanations for less aggressive treatment of high-risk patients that have been offered includes the potential adverse effects of drugs on the elderly and sickest cohorts, depression for beta-blockers, and futility in certain subsets including those with dementia. Clinical trials and studies of Medicare population outcomes find that the cost-benefit of post-MI treatments increases with increasing mortality risk. The development of the universal electronic medical record with physician and hospital feedback, and guidelines designed to force opt out and reason for opting out of a treatment may enhance the benefit of GWTG-CAD effort.
Keywords: Myocardial Infarction, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Guideline Adherence
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