[Prognostic significance of 123I-metaiodobenzylguanidine scintigraphy in dilated cardiomyopathy]

The prognostic factor was identified by performing 123I-Metaiodobenzylguanidine (MIBG) myocardial scintigraphy on 17 patients with dilated cardiomyopathy (DCM). During 5 years period, 9 patients had cardiac events, four of whom died, six were admitted due to heart failure and five had ventricular tachycardiac events. At the starting point, we collected rest early and 3-hr-delayed MIBG SPECT along with rest 201T1 (T1) SPECT. In the SPECT, regional tracer uptake was scored using 4-grades defect score (0 = normal to 3 = uptake-defect), and summed up to total defect score (TDS). At the same time, we estimated left ventricular end-diastolic dimension/body surface area (LVDd/BSA), end-systolic dimension/body surface area (LVDs/BSA) and left ventricular ejection fraction (LVEF) by echo-cardiography, pulmonary arterial wedge pressure (PAWP) and New York Heart Association (NYHA) symptom class. We compared the clinical and hemodynamic parameters between the patients with cardiac events (group A) and the other patients (group B). TDS of delayed MIBG SPECT (p0.001), TDS of early MIBG SPECT (p0.05), TDS of T1 SPECT (p0.01), LVDd/BSA (p0.01), LVDs/BSA (p0.001) and NYHA class (p0.05) of group A were significantly larger than those of group B. But, LVEF of group A was significantly less than that of group B (p0.01). On multivariate analysis, the following parameters were independent predictors of cardiac events: TDS of delayed MIBG SPECT (p0.001), PAWP (p = 0.0124) and LVDd/BSA (p = 0.0026). These data suggest that delayed MIBG scintigraphy is thought to be important to predict cardiac events in patients with DCM.