Thirty-day rehospitalizations after acute myocardial infarction: a cohort study.

<bold>Background: </bold>Rehospitalization is a quality-of-care indicator, yet little is known about its occurrence and predictors after myocardial infarction (MI) in the community.<bold>Objective: </bold>To examine 30-day rehospitalizations after incident MI.<bold>Design: </bold>Retrospective cohort study.<bold>Setting: </bold>Population-based registry in Olmsted County, Minnesota.<bold>Patients: </bold>3010 patients who were hospitalized in Olmsted County with first-ever MI from 1987 to 2010 and survived to hospital discharge.<bold>Measurements: </bold>Diagnoses, therapies, and complications during incident and subsequent hospitalizations were identified. Manual chart review was performed to determine the cause of all rehospitalizations. The hazard ratios and cumulative incidence of 30-day rehospitalizations were determined by using Cox proportional hazards regression models.<bold>Results: </bold>Among 3010 patients (mean age, 67 years; 40.5% female) with incident MI (31.2% ST-segment elevation), 643 rehospitalizations occurred within 30 days in 561 (18.6%) patients. Overall, 30.2% of rehospitalizations were unrelated to the incident MI and 42.6% were related; the relationship was unclear in 27.2% of rehospitalizations. Angiography was performed in 153 (23.8%) rehospitalizations. Revascularization was performed in 103 (16.0%) rehospitalizations, of which 46 (44.7%) had no revascularization during the index hospitalization. After adjustment for potential confounders, diabetes, chronic obstructive pulmonary disease, anemia, higher Killip class, longer length of stay during the index hospitalization, and a complication of angiography or reperfusion or revascularization were associated with increased rehospitalization risk. The 30-day incidence of rehospitalization was 35.3% in patients who experienced a complication of angiography during the index MI hospitalization and 31.6% in those who experienced a complication of reperfusion or revascularization during the index MI hospitalization, compared with 16.8% in patients who had reperfusion or revascularization without complications.<bold>Limitation: </bold>This study represents the experiences of a single community.<bold>Conclusion: </bold>Comorbid conditions, longer length of stay, and complications of angiography and revascularization or reperfusion are associated with increased 30-day rehospitalization risk after MI. Many rehospitalizations seem to be unrelated to the incident MI.<bold>Primary Funding Source: </bold>National Institutes of Health. [ABSTRACT FROM AUTHOR]