Impact of rest MPI on clinical management of non-high risk chest pain in the emergency department of the VACHS

Objectives Evaluate the contribution of an early pain MPI as an integral part of the initial ED evaluation of a patient with CP.

Methods This is a retrospective review of all patients evaluated at the ED of VACHS with a pain MPI study during 9/2006 to 6/2008. Data collected includes ECG, MPI, ED disposition, TIMI risk score, Framingham cardiovascular risk and the Virginia category scale among other. The adverse cardiac outcomes included ACS event, need for revascularization and future myocardial events including non-fatal MI, ACS with revascularization or cardiovascular death at 1 month and 1 year.

Results 366 patients were evaluated. All of them had initial negative cardiac markers for AMI, 85% had chest pain upon arrival and 93% had absence of acute ischemia on baseline ECG. 29% had known CAD, the mean TIMI score was 2 and the mean 10-year Framingham CV risk for the male and female respectively was 12% and 2%. The frequency of +MPI studies was 32%. There were 26.5% admissions. Of these, 91% were related to a +MPI. Higher TIMI score and lower Virginia Category was progressively associated with higher frequency of +MPI studies (p<0.0001. Of the patients admitted with +MPI 84% (74/88) had a confirmatory test. The positive predictive value of this study for identifying ACS or MACE at 1 month was 43% (51/119). The total number of patients discharged from ED with -MPI test was 91% (245/270). There were no cardiovascular fatalities at 1 year from evaluation. Outcomes at 1 and 3 months were low and similar, with only 0.4% (one AMI event). The total outcome at one year was 2.4% (5-MI and 1 urgent revascularization). The negative predictive value at one year was 98%.

Conclusions The use of pain MPI in the evaluation of patients with CP of non-definite ACS proved to increase the sensitivity of ischemia beyond the use of an ECG and to be a safe tool to predict the absence of MACE at short and long term.

Research Support VA Caribbean Healthcare Syste