Heart rate variability after long-term treatment with atorvastatin in hypercholesterolaemic patients with or without coronary artery disease

Low heart rate variability (HRV) level, indicative of impaired autonomic fu nction. is associated with an increased risk of cardiovascular morbidity an d mortality and is negatively affected by hypercholesterolaemia. In order t o test the hypothesis that significant low density lipoprotein (LDL) choles terol reduction after treatment with a statin will have a beneficial effect on HRV level in hypercholesterolaemic patients with or without coronary ar tery disease (CAD), forty consecutive patients (28 men and 12 women) with a median age of 61, range (17-70) years were studied. Twenty had stable CAD and 20 were free of CAD at baseline. Twenty healthy volunteers, of similar age and gender as the patients, were used as controls. Patients were treate d with atorvastatin (20 mg/day) for 2 years. Changes in lipid parameters an d HRV indices were assessed at baseline and 2 years later in all subjects. In both patient subgroups a significant beneficial change in all lipid para meters (more pronounced in the CAD + subgroup) and a significant beneficial modification in HRV time and frequency domain indices was recorded (more p ronounced in the CAD subgroup), while lipid parameters and HRV indices rema ined unchanged in the control group. A correlation between LDL concentratio ns and most of the HRV indices was found at baseline in both patient subgro ups, while no such correlation was found between values or their percent ch anges after hypolipidaemic treatment. These data suggest that treatment wit h atorvastatin improves autonomic function, as reflected by an increase in HRV level, and this may be a likely mechanism, at least in part, for the re duction in clinical events reported by the landmark survival studies with s tatins in primary and secondary CAD prevention. Perhaps, if this finding is confirmed by larger studies, HRV level may prove to be a useful tool for r isk-stratification and treatment guide in high-risk patients with hyperchol esterolaemia, regardless of CAD. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.