Novel Measures of Heart Rate Variability Predict Cardiovascular Mortality in Older Adults Independent of Traditional Cardiovascular Risk Factors: The Cardiovascular Health Study (CHS)

• Type of Material: Article
• Authors: Phyllis K. Stein, Washington University; Joshua I. Barzilay, Emory University; Paulo H. M. Chaves, Johns Hopkins University; Stephanie Q. Mistretta, Washington University; Peter P. Domitrovich, Washington University; John S. Gottdiener, University of Maryland; Michael W. Rich, Washington University; Robert E. Kleiger, Washington University
• Language: English
• Date: 2008-11-01
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2008 Wiley Periodicals, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1111/j.1540-8167.2008.01232.x
• Title of Journal or Parent Work: Journal of Cardiovascular Electrophysiology
• ISSN: 1045-3873
• Volume: 19
• Issue: 11
• Start Page: 1169
• End Page: 1174
• Grant/Funding Information: The research reported in this article was supported by contracts N01-HC-85079 through N01-HC-85086, N01-HC-35129, N01 HC-15103, N01 HC-55222, and U01 HL080295; and also by R0-1 HL62181 from the National Heart, Lung, and Blood Institute; with additional contribution from the National Institute of Neurological Disorders and Stroke.
• Keywords: RATE TURBULENCE; Life Sciences & Biomedicine; heart rate turbulence; EVENTS; risk factor; heart rate variability; Science & Technology; POSTMYOCARDIAL INFARCTION; elderly; ventricular ectopy; Cardiovascular System & Cardiology; VENTRICULAR-ARRHYTHMIAS; DISEASE; Cardiac & Cardiovascular Systems; ACUTE MYOCARDIAL-INFARCTION
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

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 ≥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) or high (>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.