Atorvastatin Therapy Increases Heart Rate Variability, Decreases QT Variability, and Shortens QTc Interval Duration in Patients With Advanced Chronic Heart Failure

Abstract Background Although statins decrease the incidence of ventricular arrhythmias in patients with atherosclerotic heart disease, their potential antiarrhythmic effects in heart failure remain undefined. Methods and Results Of 80 heart failure patients enrolled, 40 were randomized to receive atorvastatin (statin group); the remaining 40 served as controls. At baseline and after 3 months, we measured heart rate variability (HRV), QT variability (QTV), and QTc interval using interactive high-resolution electrocardiogram analysis. The 2 groups did not differ in baseline HRV standard deviation of normal-to-normal intervals (SDNN) (RR): 24.6 ± 2.8 ms in statin group versus 24.8 ± 3.1 ms in controls, P = .72; square root of the mean of squared differences between successive intervals (rMSSD) (RR): 21.2 ± 2.7 ms versus 21.7 ± 2.9 ms, P = .43), QTV SDNN (QT): 6.4 ± 1.5 ms versus 6.4±1.7, P = .96; rMSSD QT): 9.0 ± 2.4 ms versus 8.7 ± 2.9 ms, P = .65, and QTc interval 450 ± 30 ms versus 446 ± 27 ms, P = .59. At 3 months, the statin group displayed higher HRV SDNN RR): 27.2 ± 4.9 ms versus 24.4 ± 2.8 ms in controls, P = .003; rMSSD RR: 24.7 ± 4.2 ms versus 21.3 ± 5.6 ms, P = .004, lower QTV SDNN (QT): 5.1 ± 1.9 ms versus 6.5 ± 2.1, P = .004; rMSSD (QT): 6.6 ± 2.8 ms versus 8.8 ± 3.1 ms, P = .002, and shorter QTc interval 437 ± 29 ms versus 450 ± 25 ms, P = .03 than the control group. Conclusions Atorvastatin increases HRV, decreases QTV, and shortens QTc interval, and may thereby reduce the risk of arrhythmias in patients with advanced heart failure.