Impact of Rest Myocardial Perfusion Imaging on Clinical Management of Non-High Risk Chest Pain in the VA Caribbean Healthcare System Emergency Department: 2006-2008

Abstract

Objective: To evaluate the appropriate clinical use of an acute rest myocardial perfusion imaging (R-MPI) in the initial emergency department (ED) evaluation of a patient presenting with chest pain (CP). Methods: This is a retrospective study of patients evaluated with CP at the ED with an acute R-MPI. The data collected included medical history, clinical presentation, electrocardiogram, laboratory data, MPI results, confirmatory studies, disposition diagnosis and cost analysis. Results: Three-hundred-sixty-six (366) patients were evaluated. The population studied had a mean Thrombolysis in Myocardial Infarction (TIMI) score of 2 and predominance of patients in the Virginia Commonwealth University (VCU) CP Category-Scale between level 3 and 4 (34% and 49% respectively). The risk of acute coronary syndrome (ACS) was significantly higher in patients with abnormal compared to normal studies (50% versus 0.4%; P < .0005; RR, 129.5; 95% CI, 18 to 924). There were a total of 14 and 19 major adverse cardiovascular events (MACE) events during the follow-up of 30-days and 1-year respectively. There were no cardiovascular fatalities. The risk of MACE at 30-days was significantly higher in patients with abnormal compared to normal studies (12% versus 0.4%; P < .001; RR, 32; 95% CI, 4.2 to 240), as well as with 1-year of follow-up (14% versus 1.6%; P < .001; RR, 9.1; 95% CI, 3.1 to 27). Conclusion: Using acute R-MPI in the evaluation of non-high risk patients presenting with CP is a safe, reliable and cost-effective strategy to be used in the ED to predict ACS and future MACE.