Abstract 1411: The Role of Statins in Reducing Central Sympathetic Outflow in CHF
Background: Sympathoexcitation is one of the key characteristics of chronic heart failure, with well-known detrimental effects on the heart. Current therapy has mainly focused on protecting against high sympathetic tone by receptor blockade. In experimental studies statin therapy has shown to reduce central sympathetic outflow by a NO mediated mechanism. We hypothesized that statin therapy reduces central sympathetic overactivity in CHF patients.
Methods: Patients diagnosed with CHF according to the modified Framingham Clinical Criteria for the diagnosis of Heart Failure were included in our study. All patients had to be on statin treatment for at least 3 months prior to the study. Sympathetic nervous system activity was measured during, 8 weeks after discontinuation and 4 weeks after restart of statin therapy by a combination of techniques: direct muscle sympathetic nerve recording (MSNA), heart rate variability (HRV) and forearm norepinephrine (NE) spill-over. Additionally, changes in hemodynamics and cholesterol levels were analyzed.
Results: Eight patients were included in the study: mean NYHA class (±SD) 2.6±0.9, age 54.6±8 years and BMI 31.4.9±6.6. Seven patients used simvastatin (40 mg/day) and one patient was on atorvastatin (40 mg/day). After discontinuation of statin therapy, central sympathetic outflow (sympathetic burst frequency) increased significantly (mean burst frequency 55.8±4.9 vs. 73.3±4.0 bursts/100 beats, p=0.03), again returning to baseline after statin therapy restart (55.8±4.9 vs. 51.6±5.9). LF/HF ratios changed accordingly, although due to small numbers did not reaching statistical significance. Discontinuation of statin therapy had no effect on forearm NE-spill-over or hemodynamics.
Conclusion: Statin therapy reduces central sympathetic outflow in CHF patients, as measured by muscle sympathetic nerve activity. This effect is not translated in changes in forearm NE-spill over or hemodynamics. Besides beneficial cardiovascular effects by cholesterol lowering, statins may thus also have favourable effects on sympathetic overactivity.