Abstract 363: Chest Pain Observation Unit: Does Post-Discharge Stress Testing Influence Physician Management Decisions?

Abstract

Background: Chest pain (CP) accounts for approximately 6 million emergency visits per year in the United States. There is growing interest in strategies to effectively risk stratify pts for coronary artery disease (CAD) related events in a cost-effective manner. The use of chest pain observation units followed by early stress testing is frequently employed in these pts. However the utility of stress testing in this population is not well defined, and the effect of stress test results on subsequent management decisions is a topic of controversy. In the present study we examined the relationship of stress myocardial perfusion imaging (MPI) results to physician decisions regarding ccath in a single community teaching hospital. Methods: Retrospective study of 426 pts undergoing a chest pain observation strategy over a 24 month period. Pt eligible for the program had CP deemed possibly related to CAD but no diagnostic ECG changes and negative TnI measurements x2. All pts underwent outpt. stress MPI within 72 hours of discharge. Pts saw a cardiologist the day of stress MPI who reviewed the CP history, MPI results, and made decisions regarding further risk stratification. Demographic and medical history was collected from the pts chest pain observation unit record. Multivariate regression analysis was used to determine significant independent variables related to physician decisions regarding further risk stratification. Results: Of 426 pts who underwent outpt stress MPI, 71(16.7%) were positive for ischemia, and 16 (22.5% of +MPI) underwent cath with reperfusion performed in 8 (5PCI, 3 CABG, 11.3% of +MPI). Of the 355 pts with negative stress MPI, 5(1.4% of -MPI) underwent cath with reperfusion performed in 2 (2PCI, 0 CABG, 0.5% of -MPI). A MLR model suggested only stress MPI results were independently predictive of the use of ccath for risk stratification. Conclusion: Stress MPI was an important factor in physician decision-making regarding the need for ccath in pts managed in a chest pain observation unit. The rate of +MPI and subsequent use of ccath in our institution supports MPI as an appropriate step in risk stratification of low to moderate risk CP pts triaged through a CP observation unit.