Clinical significance of H/M and SS Value in Postischemic and Idiopathic Heart Failure

The prognostic value of semiquantitative parameters of myocardial 123 I‐MIBG uptake for identifying higher vs lower risk respectively for adverse cardiac events in pts with LVEF≤35% (late H/M ratio<1.6) and lethal arrhythmias (late SS>26) have been recently demonstrated, both in ischemic and idiopathic HF. The aim of our study was to confirm their prognostic independent value in ischemic and idiopathic HF pts, both with primary systolic or diastolic dysfunction, and try to find out if there is a relationship between the site of primary acute event ( acute myocardial infarction, AMI) in post‐ischemic HF and the extension of denervation. 29 HF pts were enrolled, 17 with post‐ischemic HF and 12 with idiopathic HF. They were i.v. injected with 185 MBq of 123 I‐MIBG and 15 minute and 4 hours planar and SPET scan were obtained. H/M and SS were calculated for both early and delayed images. 123 I‐MIBG uptake was decreased in 12/29 pts (10 post‐ischemic pts and 2 idiopathic pts) and preserved in 17/29 pts (10 post‐ischemic pts and 7 idiopathic pts); LVEF was <30% in 7/12 pts with pathological study. Late H/M was <1.6 in 12/12 pts with pathological studies and late SS was >26 in 6/12 pts. The multiparametric analysis of LVEF, late H/M, late SS, and AMI site revealed a statistically significant correlation between late H/M and LVEF (p value = 0.001 at Fisher’s Exact Test); no statistical correlation was found between site of AMI and extension of denervation. Conclusion The sympathetic denervation in ischemic HF seems to be more severe than that in idiopathic HF (both with systolic or diastolic primary damage): this may suggests that ischemia can produce a more sympathetic fibers injury than that in idiopathic HF. The global denervation (H/M) is constantly decreased in HF, but not the extension of denervation (SS): this may suggests that, despite of an increased risk of cardiac events, the risk for arrhythmias is an independent variable among HF pts. The lack of correlation between the AMI site and the extension of denervation confirms the same prognostic value of H/M and SS both in ischemic and idiopathic HF.