Abstract 17950: Prediction of Sudden Cardiac Death in Chronic Heart Failure Patients with Mild to Moderate Systolic Dysfunction a Prospective Comparative Study of Cardiac I-123 Metaiodobenzylguanidine Imaging and Heart Rate Turbulence
Background: Although it is shown that ICD therapy could prevent sudden cardiac death (SCD) in chronic heart failure (CHF) patients with severely reduced LV systolic function (LV ejection fraction <35%), it remains unclear which CHF patients with LVEF>35% would have the risk of SCD. Therefore, we sought to prospectively compare the prognostic values for SCD of cardiac metaiodobenzylguanidine (MIBG) imaging and heart rate turbulence (HRT) analysis ,which are expected to provide prognostic information , in CHF patients with LVEF>35% in the gray zone for the ICD therapy.
Methods and Results: We enrolled 55 CHF outpatients (NYHA 2±0.2) with radionuclide LV ejection fraction from 35% to 50% (38.5±0.8%). We performed the cardiac MIBG imaging and 24-hour Holter monitoring at the entry. The cardiac MIBG wash out rate (WR) was calculated from the chest anterior view images obtained at 20 and 200 min after isotope injection. Abnormal WR was defined as WR >27%. Furthermore, we also performed HRT analysis from Holter monitoring. Turbulance onset (TO) and turbulence slope (TS) were calculated as HRT parameters. Abnormal values of HRT analysis were defined as TO≥0% and TS≤2.5ms/beat.
Result: During the follow up period of 6.0±0.8 years, 7 of 55 patients had SCD. At multivariate Cox analysis, WR was significantly (p=0.015) and independently associated with SCD, while TO and TS had no association with SCD. SCD was significantly more frequently observed in patients with than without abnormal WR (30% vs 3%, p=0.002), although there was no significant difference in the incidence of SCD between patients with and without abnormal HRT results. The hazard ratio of abnormal WR for SCD was 13 .7( 95%CI 1.6 to 114.7).
Conclusion: Cardiac MIBG imaging, but not HRT analysis, would be useful to predict the risk of sudden cardiac death in CHF patients with mildly to moderately reduced LV systolic function.
- © 2011 by American Heart Association, Inc.