Abstract 14565: Prediction of Sudden Cardiac Death in Patients With Chronic Heart Failure by the Combination of the Cardiac MIBG Global Washout Rate and Regional Washout Rate Dispersion
Background: Cardiac MIBG imaging, which has been mainly evaluated on the planar images, provides prognostic information in patients with chronic heart failure (CHF). The identification of CHF pts at risk for sudden cardiac death (SCD) remains an important goal. The sympathetic nervous system provides an important trigger for major arrhythmic events through regional heterogeneity of sympathetic activity, which could be evaluated by the SPECT imaging as the regional dispersion of MIBG washout rate (WR). We sought to investigate whether the regional WR dispersion (WRd) in SPECT imaging would provide additional prognostic value to global WR in the planar images for predicting SCD.
Methods and Results: We studied 73 CHF outpatients with LVEF<40%. At the entry, cardiac MIBG global WR was calculated from the chest anterior planer images obtained at 20 and 200 min after isotope injection. Furthermore, the regional WRd was obtained by subtracting the minimum regional WR from the maximum regional WR (max-rWR) of 17 segments in the polar map. During a mean follow-up of 7.5±4.1 years, 15 of 73 pts had SCD. Multivariate Cox analysis revealed that abnormal (>27%) global WR (p=0.02, Hazard Ratio:6.5(95%CI 1.3-32.8)) and the increased regional WRd (p=0.01, Hazard Ratio:4.1 (95%CI 1.3-13.3)), which we defined as both WRd and max-rWR > the median values (26.3% and 32.1% respectively), were independently associated with SCD. Pts with both abnormal global WR and increased regional WRd had a significantly higher risk of SCD than those with either abnormal global WR or increased WRd and none of these criteria (p<0.0001, 45% vs 15% vs 9%,respectively). The HR in pts with both abnormal global WR and the increased regional WRd was 20.8 (95%CI 4.3-101.2), which was 3 fold greater than that in pts with abnormal global WR.
Conclusion: The increased regional WR dispersion in SPECT imaging would provide additional prognostic value to global WR in the planar images for predicting SCD in CHF pts.
- © 2013 by American Heart Association, Inc.