New York Heart Association Functional class influences the impact of diabetes on cardiac autonomic function

BackgroundDiabetes (D) and heart failure (HF) are associated with abnormal heart rate variability (HRV). It is unclear whether the HRV effect of having both is cumulative.MethodsPretreatment HRV (traditional, nonlinear, and heart rate [HR] turbulence) in 80 D versus 74 non-D (ND) systolic HF patients was compared by New York Heart Association II versus III among patients entered into an HF drug evaluation study.ResultsAge-adjusted HR was lower in class II D versus class III and most HRV including HR turbulence was better in class II ND versus all others, with few differences between class II D and class III ND and D patients.ConclusionThe effect of D and HF on autonomic function may be cumulative in class II, but D may have little additional effect on most HRV in class III patients. The prognostic value of different HRV measures in D versus ND HF patients should be further investigated.