Abstract 12142: Quantitative Segmental Analysis of Myocardial Perfusion for Differentiating Stress Cardiomyopathy versus Acute Myocardial Infarction: A Myocardial Contrast Echocardiography Study

Abstract

Background: Both stress cardiomyopathy (SCMP) and acute myocardial infarction (AMI) can present with similar clinical symptom/sign and apical akinesis. Noninvasive differential diagnosis using myocardial contrast echocardiography (MCE) may be promising for this purpose, but value of quantitative segmental analysis remains to be evaluated.

Method: A real-time MCE was performed in 31 consecutive patients who showed new apical akinesis on echocardiography. Left ventricular myocardium was divided into 18 segments on apical 4-, 2-, and 3-chamber views and replenishment curve was obtained in each segment to measure the peak myocardial contrast intensity (CI) (A, dB) and the slope of the replenishment curve (ß, /s). The calibrated CI was also measured in each segment by subtracting the cavity CI from myocardial CI to standardize heterogeneity of CI among myocardial segments.

Results: According to comprehensive diagnostic criteria, 25 and 6 patients were finally diagnosed as SCMP and AMI, respectively. Quantitative analysis was validated in 306 (68%) and 85 (79%) segments in SCMP and AMI patients, respectively. A, ß, Aß, and calibrated CI were lower in akinetic than in normokinetic segments in both SCMP and AMI groups (Table). In akinetic segments, A, ß, Aß, and calibrated CI in SCMP were all higher than those in AMI patients. The ratio of calibrated CI in apex to that in base was 1.27±0.4 in SCMP and 1.76±0.9 in AMI patients (p=0.016). Areas under the curves on ROC curve analyses of A, ß, Aß, and calibrated CI for diagnosing AMI were 0.701, 0.699, 0.777, and 0.843, respectively. The best cut-off values to diagnose AMI were Aß < 4.8 dB/sec (sensitivity 94%, specificity 56%) and calibrated CI < -23 dB (sensitivity 71%, specificity 84%).

Conclusions: Although myocardial perfusion is relatively decreased in akinetic segments of SCMP, quantitative segmental analysis of myocardial perfusion using MCE helps to discriminate AMI from SCMP.