The Institute

Monday, June 11, 2012

Statin therapy lowers muscle sympathetic nerve activity and oxidative stress in patients with heart failure.



Despite standard drug therapy, sympathetic nerve activity (SNA) remains high in heart failure (HF) patients making the sympathetic nervous system a primary drug target in the treatment of HF. Studies in rabbits with pacing-induced HF have demonstrated that statins reduce resting SNA, in part, due to reductions in reactive oxygen species (ROS). Whether these findings can be extended to the clinical setting of human HF remains unclear. We first performed a study in seven statin-naïve HF patients (56±2 yrs; ejection fraction 31±4%) to determine if one month of Simvastatin (40 mg/day) reduces muscle SNA (MSNA). Next, to control for possible placebo effects and determine the effect of Simvastatin on ROS, a double-blinded, placebo-controlled crossover design study was performed in six additional HF patients (51±3 yrs; ejection fraction 22±4%) and MSNA, and ROS and superoxide were measured. We tested the hypothesis that statin therapy decreases resting MSNA in HF patients and this would be associated with reductions in ROS. In Study 1, Simvastatin reduced resting MSNA (75±5 baseline vs. 65±5 statin bursts/100 heart beats, P<0.05). Likewise, in Study 2, Simvastatin also decreased resting MSNA (59±5 placebo vs. 45±6 statin bursts/100 heart beats, P<0.05). In addition, statin therapy significantly reduced total ROS and superoxide. As expected, cholesterol was reduced after Simvastatin. Collectively, these findings indicate that short-term statin therapy concomitantly reduces resting MSNA and total ROS and superoxide in HF patients. Thus, in addition to lowering cholesterol, statins may also be beneficial in reducing sympathetic overactivity and oxidative stress in HF patients.

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