Prognostic Value of Negative Predischarge Dobutamine Stress Echocardiography in Chest Pain Units: A Four-Year Follow Up

Abstract

Background: Risk stratification of patients with chest pain (CP) in chest pain units remains a challenge. We evaluated the utilization and outcomes of dobutamine stress echocardiography (DSE) in patients with normal or nondiagnostic electrocardiogram and negative serial troponin I. Methods: A retrospective descriptive study of consecutive patients admitted to the chest pain unit with CP, normal or nondiagnostic electrocardiogram, and negative serial troponin I and underwent DSE between January and December 1999. Baseline demographics, patient characteristics, and DSE variables were obtained through medical record review and the DSE report. Patients were followed up until January 2004 for major adverse cardiovascular events (MACE). Results: A total of 1008 patients were admitted to the chest pain unit in 1999 with chest pain. One hundred patients (9.9%) underwent DSE. Eight of 100 (8%) patients had positive studies, whereas 4 studies were inconclusive. Among the patients with negative DSE, the average age was 64 years; 67% were males and 31% had diabetes. Over the follow-up duration, 7 of 88 patients (8%) had MACE (1 cardiac death, 1 revascularization, 4 non-ST-segment elevation myocardial infarctions, and 1 cerebrovascular accident). In addition, there were 3 of 88 noncardiac deaths. In contrast, there were 2 of 8 noncardiac deaths in the positive DSE group. Conclusions: Patients with CP, nondiagnostic electrocardiograms and serum cardiac markers, and a negative predischarge DSE in chest pain units have an 8% rate of MACE at 4 years. Other high-risk features may warrant close follow up and probably further diagnostic workup.