Validation of a Five-Year Prognostic Model Using ¹²³I-metaiodobenzylguanidine Scintigraphy in Patients with Heart Failure

Background: 123 I-metaiodobenzylguanidine (MIBG) scintigraphy evaluates the severity and prognosis of patients with heart failure.A prognostic model has been proposed using a multicenter study data of 123 I-MIBG scintigraphy.We evaluated the usefulness of the model using a database.Methods: The study included 208 patients with noncompensated heart failure requiring hospitalization. 123I-MIBG scintigraphy and echocardiography were performed predischarge and 6 months postdischarge.The 5-year mortality rate was calculated by the model and classified into tertiles.Results: In 208 patients, 56 cardiac deaths occurred within the observation period (median, 4.83 years).In the evaluation of predischarge parameters, the predicted 5-year mortality was 15.5%5.0%,33.5%3.9%,and 51.2%8.2%, and 11 (16.2%),18 (27.3%),and 27 (36.5%)cardiac deaths occurred in groups 1, 2, and 3, respectively.At the 6-month postdischarge evaluation, the estimated mortality was 8.2%2.2%,18.5%4.8%,and 43.0%12.1%,and 6 (9.4%),21 (29.2%), and 29 (40.3%)cardiac deaths occurred, respectively.The predischarge Kaplan-Meier survival analysis showed significant difference between groups 1 and 3 (P value 0.014).Moreover, the 6-month postdischarge evaluation showed significant difference between group 1 and 2, and between groups 1 and 3 (P value 0.016, <0.001, respectively).For groups 1 and 3, the 6-month postdischarge difference was more significant than the predischarge difference (Chi-square 16.7 and 8.1, respectively). Conclusions:The prognostic model using 123 I-MIBG scintigraphy was useful in predicting mortality risk in patients with heart failure.The estimated mortality at 6 months postdischarge was more useful than the predischarge estimation for heart failure hospitalization.