Objectives: The purpose of this study was to analyze the feasibility of early discharge (4 days) after acute myocardial infarction in patients not receiving thrombolytic therapy by first identifying predictors of short-term prognosis and then testing the derived risk profile in an independent cohort of patients.
Background: Previous studies have shown that early discharge after acute myocardial infarction is possible. However, physicians are reluctant to shorten the standard 7- to 10-day hospital stay, presumably because of difficulty in selecting low risk patients.
Methods: From January 1985 to November 1986, 358 patients with acute myocardial infarction who did not receive thrombolytic therapy were screened. Those with a Q-wave infarction showing no complications on day 4 were considered candidates for early discharge and were transferred to the ward for a mean of 12 days. During this period, we looked for any event (cardiac or noncardiac) that would have prompted readmission if the patient had been previously discharged. Univariate and multiple regression analysis were performed to identify predictors of these events among 25 baseline variables. The derived risk profile was tested in an independent validation cohort.
Results: One hundred five (29.3%) of the 358 patients were free of symptoms on day 4, and 29 (27.6%) had at least one cardiac event, including four deaths and one reinfarction. Multivariate analysis selected diabetes, ejection fraction < 40% and age as independent predictors of events. Using the risk profile, 18 (13.2%) of the 136 validation cohort patients were categorized as low risk, and only 1 of them had a major event (progressive angina). Sensitivity for the risk profile was high (91%), but specificity was low (34%).
Conclusions: The use of simple clinical variables may allow the safe reduction of hospital stay after infarction in selected patients. However because the proportion of candidates for early discharge is small (12.6%), it seems unlikely that the current policies on length of hospital stay will change in the near future.