The effect of dementia on outcomes and process of care for Medicare beneficiaries admitted with acute myocardial infarction

OBJECTIVES: To determine differences in mortality after admission for acute myocardial infarction (AMI) and in use of noninvasive and invasive treatments for AMI between patients with and without dementia. DESIGN: Retrospective chart review. SETTING: Cooperative Cardiovascular Project. PATIENTS: Medicare patients admitted for AMI (N=129,092) in 1994 and 1995. MEASUREMENTS: Dementia noted on medical chart as history of dementia, Alzheimer's disease, chronic confusion, or senility. Outcome measures included mortality at 30 days and 1-year postadmission; use of aspirin, beta-blocker, angiotensin-converting enzyme (ACE) inhibitor, thrombolytic therapy, cardiac catheterization, coronary angioplasty, and cardiac bypass surgery compared by dementia status. RESULTS: Dementia was associated with higher mortality at 30 days (relative risk (RR)=1.16, 95% confidence interval (CI)=1.09-1.22) and at 1-year postadmission (RR=1.18, 95% CI=1.13-1.23). There were few to no differences in the use of aspirin and beta-blockers between patients with and without a history of dementia. Patients with a history of dementia were less likely to receive ACE inhibitors during the stay (RR=0.89, 95% CI=0.86-0.93) or at discharge (RR=0.90, 95% CI=0.86-0.95), thrombolytic therapy (RR=0.82, 95% CI=0.74-0.90), catheterization (RR=0.51, 95% CI=0.47-0.55), coronary angioplasty (RR=0.58, 95% CI=0.51-0.66), and cardiac bypass surgery (RR=0.41, 95% CI=0.33-0.50) than patients without a history of dementia. CONCLUSION: The results imply that the presence of dementia had a major effect on mortality and care patterns for this condition.