Incremental prognostic value of myocardial neuroadrenergic damage in patients with chronic congestive heart failure: An iodine-123 meta-iodobenzylguanidine scintigraphy study

Background: ICD in primary prevention reduced mortality in patients with heart failure (HF); however, in about 80% of the ICD recipients an event requiring a device intervention will never occur. Thus, a reliable screening test included in a multiparametric approach to appropriately select patients to ICD implantation is increasingly required. Aim of the work was to assess if the Iodine-123 Meta-Iodobenzylguanidine scintigraphy (123I-mIBG) could be useful to identify patients with HF who would not benefit from the ICD implantation because at low risk of arrhythmias. Methods and results: This is a retrospective multicentre study on patients undergoing 123I-mIBG from February 2012 to December 2015. Inclusion criteria where: age ≥ 18 years old, LVEF ≤ 35% with idiopathic or ischemic heart disease, no previous malignant ventricular arrhythmias. Patients were divided in two groups based on of late H/M < or ≥ 1.60 on 123I-mIBG. Primary end-point was occurrence of malignant arrhythmias. Secondary end-point was occurrence of cardiac death and hospitalization for worsening HF. MACE were mortality and malignant arrhythmias. Eighty-one patients were enrolled (mean age: 69 years). On 123I-mIBG, 54 patients had late H/M < 1.6 and 27 patients had late H/M ≥ 1.60. After a mean follow-up of 13.3 (± 9.7) months, the primary end-point occurred in 13 patients out of 81. No arrhythmias occurred in patients with H/M late ≥ 1.6. Nineteen patients out of 20 with MACE showed an H/M late < 1.6. Death in group with H/M ≥ 1.6 occurred for worsening HF. A late H/M ≥ 1.60 showed a very high NPV for arrhythmia (100%) and for death (96.3%). Conclusion: 123I-mIBG imaging has the capability to identify patients at low risk of events.