Abstract P332: Thirty Day Readmissions After Myocardial Infarction in the Community
Background: Hospital readmissions are considered to be a quality of care indicator, yet little is known about their occurrence and predictors after myocardial infarction (MI) in the community.
Methods: We identified all Olmsted County residents with incident MI from 1987-2007 and evaluated 30-day rehospitalizations. The reason for readmission was categorized based on ICD-9 code. Safety endpoints of revascularization (percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) or fibrinolysis included stroke, acute kidney injury (rise in creatinine post-procedure of >0.5 mg/dL), access site complication (PCI), and gastrointestinal or other bleeding. Cox proportional hazard regression models were used to examine the predictors of readmission.
Results: A total of 2617 patients (mean age 67 years, 41% female) had incident MI (32% with ST-elevation) from 1987-2007 and survived their initial hospitalization. A total of 583 readmissions occurred within 30 days among 512 (19.6%) patients. Approximately half (n=286, 49.1%) of readmissions were due to cardiovascular causes, and of these, most were due to ischemic heart disease (n=175, 61.2%) or heart failure (n=56, 19.6%). The proportion of non-cardiovascular rehospitalizations increased over time, from 42.2% from 1993-97 to 59.4% from 2003-07 (p for trend=0.01). A minority of those readmitted for cardiovascular reasons required repeat angiogram (n=110, 38.5%) or revascularization (n=88, 50 PCI, 38 CABG). After adjustment for confounders, key factors were associated with increased rehospitalization risk (Figure). Following PCI (n=1230), a stroke or bleeding event (adjusted HR 1.69, 95% CI 1.09-2.61, p=0.02) and acute kidney injury (HR 2.50, 95% CI 1.61-3.87, p<0.01) were associated with markedly increased readmission risk.
Conclusions: Half of readmissions within 30 days of MI are for non-cardiovascular reasons, and this proportion has increased. Comorbidity and complications of revascularization are key predictors of readmission.
- © 2012 by American Heart Association, Inc.