Changes in Cardiac Denervation Independent of Changes in Systolic Function During Follow-up in CHF Patients

Abstract

Introduction: Regional cardiac denervation in chronic heart failure (CHF) is associated with propensity towards arrhythmogenesis and with increased cardiac effects of catecholamines. The objectives of the study were to evaluate relationships between the extent of denervation utilising metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy and markers of LV systolic dysfunction in severe CHF patients, and to assess the progression of sympathetic nervous dysfunction. Methods: 123I-MIBG was performed in 41 CHF patients (mean LVEF 30 ± 7%) and was repeated in a subgroup of 14 patients after one year. The early and delayed heart to mediastinum ratio (EHMR and DHMR) and washout rate were calculated. Echocardiographic LVDs, LVDd and LVEF as well as NT-proBNP concentrations were determined at the same time points. Results: CHF was infarct-related in 68% of the patients. At baseline, EHMR and DHMR (1.7 ± 0.18 and 1.59 ± 0.18) were significantly lower than population norms (2.42 ± 0.27 and 2.60 ± 0.15, respectively). There was a weak inverse relationship between EHMR and LVDd (r = −0.37, p = 0.025) and LVDs (r = −0.30, p = 0.086), but not with LVEF. NT-proBNP concentrations also inversely correlated with DHMR (r = −0.33, p = 0.04). As regards the progression of myocardial denervation, there was a significant decrease in DHMR (1.55 ± 0.25 vs.1.26 ± 0.3, p = 0.0002), with no significant change in LV functional parameters or NT-pro-BNP levels. Conclusions: CHF is associated with marked myocardial sympathetic dysfunction, which is weakly correlated with LVD and NT-proBNP concentrations. Sympathetic nervous activity deteriorated significantly during 12 months follow-up, independently of changes in systolic function.