The combination of low DFA1 and abnormal heart rate turbulence strongly predicted cardiovascular death across Framingham Risk Score strata (RR 7.7 for low, 3.6 for mid, and 2.8 for high FRS).
Cohort (n=1,172)
Do abnormal heart rate turbulence and low DFA1 predict cardiovascular death in community-dwelling older adults?
The combination of low DFA1 and abnormal heart rate turbulence is a strong predictor of cardiovascular mortality in older adults, independent of traditional risk factors.
Effect estimate: RR 7.7 (low FRS), 3.6 (mid FRS), 2.8 (high FRS)
UNLABELLED: Novel HRV Predicts CV Mortality in the Elderly. BACKGROUND: It is unknown whether abnormal heart rate turbulence (HRT) and abnormal fractal properties of heart rate variability identify older adults at increased risk of cardiovascular death (CVdth). METHODS: Data from 1,172 community-dwelling adults, ages 72 +/- 5 (65-93) years, who participated in the Cardiovascular Health Study (CHS), a study of risk factors for CV disease in people >or=65 years. HRT and the short-term fractal scaling exponent (DFA1) derived from 24-hour Holter recordings. HRT categorized as: normal (turbulence slope TS and turbulence onset TO normal) or abnormal (TS and/or TO abnormal). DFA1 categorized as low (1). Cox regression analyses stratified by Framingham Risk Score (FRS) strata (low = 20) and adjusted for prevalent clinical cardiovascular disease (CVD), diabetes, and quartiles of ventricular premature beat counts (VPCs). RESULTS: CVdths (N = 172) occurred over a median follow-up of 12.3 years. Within each FRS stratum, low DFA1 + abnormal HRT predicted risk of CVdth (RR = 7.7 for low FRS; 3.6, mid FRS; 2.8, high FRS). Among high FRS stratum participants, low DFA1 alone also predicted CVdth (RR = 2.0). VPCs in the highest quartile predicted CVdth, but only in the high FRS group. Clinical CV disease predicted CVdth at each FRS stratum (RR = 2.9, low; 2.6, mid; and 1.9, high). Diabetes predicted CVdth in the highest FRS group only (RR = 2.2). CONCLUSIONS: The combination of low DFA1 + abnormal HRT is a strong risk factor for CVdth among older adults even after adjustment for conventional CVD risk measures and the presence of CVD.
Stein et al. (Wed,) conducted a cohort in Cardiovascular disease risk (n=1,172). Low DFA1 and abnormal HRT vs. Normal HRT and/or high DFA1 was evaluated on Cardiovascular death (RR 7.7 (low FRS), 3.6 (mid FRS), 2.8 (high FRS)). The combination of low DFA1 and abnormal heart rate turbulence strongly predicted cardiovascular death across Framingham Risk Score strata (RR 7.7 for low, 3.6 for mid, and 2.8 for high FRS).