Paradoxical Prognostic Implications of Visceral Adiposity for Lethal Cardiac Events in Association with Impaired Cardiac Sympathetic Innervation in Chronic Heart Failure.

Background: Obesity increases the risk for development of heart failure (HF) but, when present is likely to be related to better outcomes in patients with HF. This study aimed to clarify the paradoxical prognostic values of visceral obesity in association with cardiac sympathetic function in HF patients. Methods and Results: A total of 653 consecutive patients with systolic HF who underwent visceral adiposity area (VAA) measurements using a computed tomographic technique were divided into 3 groups: VAA 1, area <80 cm²; VAA 2, area 80-140 cm²; VAA 3, area >140 cm². Sympathetic innervation was quantified by ¹²³I-MIBG cardiac activity. Patients were followed up for an average of 22 months with a primary endpoint of lethal cardiac events (CE). The CE group (n=200) had a lower late heart-to mediastinum ratio (HMR) and a smaller VAA than those in the non-CE group. Rates of overall CE/HF death were inversely correlated with VAA: 39.2% ± 6.2% for VAA 1, 27.4% ± 19.9% for VAA 2 and 24.1% ± 15.3% for VAA 3. In addition to sudden cardiac death rate, lethal arrhythmic event rate increased in association with visceral fat obesity: 3.0% for VAA 1, 7.5% for VAA 2 and 8.8% for VAA 3. Late HMR identified high-risk sub-populations in each group. Conclusion: Visceral obesity has paradoxical prognostic implications in terms of HF mortality and lethal arrhythmic/sudden cardiac death events. Cardiac sympathetic denervation and quantitative visceral adiposity are synergistically associated with overall cardiac mortality, contributing to better risk stratification of HF patients.