Comparison between Echocardiography and Gated SPECT in the Assessment of Left Ventricular Wall Motion in Patients with Acute Myocardial Infarction

ABSTRACT

BACKGROUND AND OBJECTIVES: Assessment of the regional left ventricular function provides valuable diagnostic and prognostic information of patients with coronary artery disease. The aim of the study was to analyze the agreement between wall motion scores, derived by gated single photon emission computed tomography (SPECT) and echocardiography (Echo) in myocardial infarction patients with a perfusion defect. SUBJECTS AND METHODS: We studied the regional wall motion in 81 patients with an acute myocardial infarction, who underwent adenosine stress gated SPECT and Echo. Echo was performed in all the patients immediately prior to, or following, gated SPECT. The regional wall motion was evaluated by both modalities, and scored using a 16-segment model with a 4-point scoring system: 1=normal, 2=mild and moderate hypokinesia, 3=severe hypokinesia, 4=akinesia or dyskinesia. RESULTS: There was a high agreement in the left ventricular regional wall motion scores between the gated SPECT and the Echo of 84.2% of segments (1091/1296 segments, k=0.76, p<0.0001). The agreement in the regional wall motion scores between the two modalities decreased significantly along the longitudinal axis of the left ventricle from 92.9% (301/324, k=0.89, p<0.0001) at the apex, 84.6% (411/486, k=0.77, p<0.0001) at the mid point, to 77.9% (379/486, k=0.65, p<0.0001) at the basal segments (p<0.0001). Also, the agreement based on the degree of myocardial perfusion was 86.6% for segments with normal, or mild hypoperfusion, and 82.6% with moderate to severe hypoperfusion (p=0.072). CONCLUSION: The gated SPECT had a good agreement with the Echo for the assessment of the left ventricular regional wall motion in patients with an acute myocardial infarction. These results support the clinical use of gated SPECT.