Differences in management and outcomes of acute myocardial infarction among four general hospitals in Japan

Objective: To ascertain the differences among hospitals in Japan in the management patterns and outcomes of patients with acute myocardial infarction (AMI). Design: Retrospective cohort study by means of patient chart review. Setting: Four tertiary-care teaching hospitals in Japan observed over a 1-year period. Study participants: Consecutive patients (N=482) admitted for AMI. Main outcome measures: Clinical characteristics, rates of diagnostic and therapeutic procedures performed, cardiac complications, and length of stay. Results: Patients’ clinical characteristics differed significantly among the four hospitals in terms of age, gender, and prior cardiac history, but not in terms of comorbidity or infarct location. The frequency and type of diagnostic and therapeutic procedures were different, and in-hospital mortality varied (4–14%, P=0.022). Average length of hospital stay ranged from 15.8±12.6 days to 41.0±19.4 days (P=0.0001). After adjustment for the clinical characteristics, these differences remained significant among hospitals. Conclusion: Considerable differences in the management and outcomes of patients with AMI exist in Japan.