@article {1042, title = {Novel measures of heart rate variability predict cardiovascular mortality in older adults independent of traditional cardiovascular risk factors: the Cardiovascular Health Study (CHS).}, journal = {J Cardiovasc Electrophysiol}, volume = {19}, year = {2008}, month = {2008 Nov}, pages = {1169-74}, abstract = {

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 = <10, mid = 10-20, and high >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.

}, keywords = {Aged, Aged, 80 and over, Arrhythmias, Cardiac, Death, Sudden, Cardiac, Electrocardiography, Ambulatory, Female, Heart Rate, Humans, Male, Maryland, Reproducibility of Results, Risk Assessment, Risk Factors, Sensitivity and Specificity, Survival Analysis, Survival Rate}, issn = {1540-8167}, doi = {10.1111/j.1540-8167.2008.01232.x}, author = {Stein, Phyllis K and Barzilay, Joshua I and Chaves, Paulo H M and Mistretta, Stephanie Q and Domitrovich, Peter P and Gottdiener, John S and Rich, Michael W and Kleiger, Robert E} }