Abstract 6127: Usefulness of Cardiac I-123 Metaiodobenzylguanidine Imaging for Predictor of Sudden Cardiac Death in Chronic Heart Failure Patients with Mild to Moderate Systolic Dysfunction: A 10- Year Follow up Study
Background: The identification of patients at risk for sudden cardiac death (SCD) in chronic heart failure (CHF) still remains to be an important goal. Although it is shown that ICD therapy could prevent SCD in CHF pts with severely reduced LV systolic function (LV ejection fraction <35%), it remains unclear which CHF pts with LVEF>35% would have the risk of SCD. Cardiac metaiodobenzylguanidine (MIBG) imaging provides prognostic information in CHF pts. We sought to prospectively investigate whether cardiac MIBG imaging could predict SCD in pts with mildly to moderately reduced LV systolic function (LVEF>35%) of the gray zone for the ICD therapy.
Methods and Results: In 60 pts with radionuclide LVEF from 35% to 45% (38.3±2.8), the cardiac MIBG heart to mediastinum ratio (H/M) and wash out rate (WR) were calculated from the chest anterior view images obtained at 20 and 200 min after isotope injection. Abnormal WR was defined as WR >27%. They were followed up for >10 years.
Result: During the follow up period of 6.0±3.1 years (0.4–11.0), 8 (32%) of 25 with abnormal WR died suddenly, while SCD was observed in only one (3%) of 35 patients with normal WR. Kaplan-Meier analysis revealed that SCD was significantly more frequently observed in the abnormal WR group than in the normal WR group (p=0.002). At Cox regression analysis, out of the variables including clinical, echocardiographic, hemodynamic, biochemical and MIBG parameter, abnormal WR was the only predictor of SCD(p=0.016, hazard ratio 12.7 [95%CI 1.6 to 101.9])
Conclusion: Cardiac MIBG imaging would be useful to predict the risk of sudden cardiac death in patients with CHF and mildly to moderately depressed function.