@article {859, title = {Sometimes higher heart rate variability is not better heart rate variability: results of graphical and nonlinear analyses.}, journal = {J Cardiovasc Electrophysiol}, volume = {16}, year = {2005}, month = {2005 Sep}, pages = {954-9}, abstract = {

OBJECTIVE: To determine the prevalence and effect on traditional heart rate variability (HRV) indices of abnormal HRV patterns in the elderly.

METHODS: Hourly Poincar{\'e} plots and plots of spectral HRV from normal-to-normal interbeat intervals and hourly nonlinear HRV values were examined in a subset of 290 consecutive participants in the Cardiovascular Health Study. Only subjects in normal sinus rhythm with > or = 18 hours of usable data were included. Eligible subjects were 71 +/- 5 years. During 7 years of follow-up, 21.7\% had died. Hours were scored as normal (0), borderline (0.5), or abnormal (1) from a combination of plot appearance and HRV. Summed scores were normalized to 100\% to create an abnormality score (ABN). Short-term HRV versus each 5th percentile of ABN was plotted and a cutpoint for markedly increased HRV identified. The t-tests compared HRV for subjects above and below this cutpoint. Cox regression evaluated the association of ABN and mortality.

RESULTS: Of 5,815 eligible hourly plots, 64.4\% were normal, 14.5\% borderline, and 21.1\% abnormal. HR, SDNN, SDNNIDX, ln VLF and LF power, and power law slope did not differ by the cutpoint for increased short-term HRV, while SDANN and ln ULF power were significantly lower for those above the cutpoint. However, many HRV indices including LF/HF ratio and normalized LF and HF power were significantly different between groups (P < 0.001). Increased ABN was significantly associated with mortality (P = 0.019). Despite similar values for many HRV indices, being in the group above the cutpoint was significantly associated with mortality (P = 0.04).

CONCLUSIONS: Abnormal HR patterns that elevate many HRV indices are prevalent among the elderly and associated with higher risk of mortality. Consideration of abnormal HRV may improve HRV-based risk stratification.

}, keywords = {Aged, Aged, 80 and over, Algorithms, Arrhythmia, Sinus, Cohort Studies, Diagnosis, Computer-Assisted, Electrocardiography, Female, Heart Rate, Humans, Male, Models, Cardiovascular, Nonlinear Dynamics, Numerical Analysis, Computer-Assisted, Prevalence, Proportional Hazards Models, Reproducibility of Results, Risk Assessment, Risk Factors, Sensitivity and Specificity, United States}, issn = {1045-3873}, doi = {10.1111/j.1540-8167.2005.40788.x}, author = {Stein, Phyllis K and Domitrovich, Peter P and Hui, Nelson and Rautaharju, Pentti and Gottdiener, John} } @article {910, title = {Dietary fish and n-3 fatty acid intake and cardiac electrocardiographic parameters in humans.}, journal = {J Am Coll Cardiol}, volume = {48}, year = {2006}, month = {2006 Aug 01}, pages = {478-84}, abstract = {

OBJECTIVES: We evaluated the association between dietary fish intake and several cardiac electrocardiographic parameters in humans relevant to arrhythmic risk.

BACKGROUND: Fish consumption may reduce the incidence of sudden death and atrial fibrillation, possibly related to anti-arrhythmic effects.

METHODS: In a population-based study of 5,096 men and women, we evaluated cross-sectional associations between usual dietary fish intake and electrocardiographic measures of heart rate, atrioventricular conduction (PR interval), ventricular repolarization (QT interval), and ventricular conduction (QRS interval). Multivariate models were adjusted for age, gender, race, education, smoking, body mass index, diabetes, coronary heart disease, physical activity, and intakes of beef or pork, fried fish, fruits, vegetables, alcohol, and total calories.

RESULTS: Consumption of tuna or other broiled or baked fish (comparing the highest to the lowest category of intake) was associated with lower heart rate (-3.2 beats/min, 95\% confidence interval [CI] = 1.3 to 5.1; p trend <0.001), slower atrioventricular conduction (PR interval +7.2 ms, 95\% CI = 1.4 to 12.9; p trend = 0.03), and substantially lower likelihood of prolonged QT (relative risk = 0.50, 95\% CI = 0.27 to 0.95; p trend = 0.03). Tuna/other fish intake was not associated with ventricular conduction (p = 0.60). Findings were similar for estimated intake of marine n-3 fatty acids: a 1 g/day higher intake was associated with 2.3 beats/min lower heart rate (95\% CI = 0.9 to 3.7), 7.6 ms longer PR interval (95\% CI = 3.3 to 11.9), and 46\% lower likelihood of prolonged QT (relative risk = 0.54, 95\% CI = 0.33 to 0.88).

CONCLUSIONS: These findings in this large, population-based study suggest that dietary fish intake is associated with cardiac electrophysiology in humans, including heart rate, atrioventricular conduction, and ventricular repolarization, with potential implications for arrhythmic risk.

}, keywords = {Aged, Animals, Atrioventricular Node, Cross-Sectional Studies, Diet, Electrocardiography, Fatty Acids, Omega-3, Female, Fishes, Heart, Heart Rate, Humans, Male, Ventricular Function}, issn = {1558-3597}, doi = {10.1016/j.jacc.2006.03.048}, author = {Mozaffarian, Dariush and Prineas, Ronald J and Stein, Phyllis K and Siscovick, David S} } @article {1020, title = {Dietary fish and omega-3 fatty acid consumption and heart rate variability in US adults.}, journal = {Circulation}, volume = {117}, year = {2008}, month = {2008 Mar 04}, pages = {1130-7}, abstract = {

BACKGROUND: Fish and omega-3 fatty acid consumption reduce risk of cardiac death, but mechanisms are not well established. Heart rate variability (HRV) predicts cardiac death and reflects specific electrophysiological pathways and influences. We hypothesized that habitual consumption of fish and marine omega-3 fatty acids would be associated with more favorable HRV, elucidating electrophysiological influences and supporting effects on clinical risk.

METHODS AND RESULTS: In a population-based cohort of older US adults, we evaluated cross-sectional associations of usual dietary fish and omega-3 consumption during the prior year and ECG-derived (n=4263) and 24-hour Holter monitor-derived (n=1152) HRV. After multivariable adjustment, consumption of tuna or other broiled/baked fish was associated with specific HRV components, including indices suggesting greater vagal predominance and moderated baroreceptor responses (eg, higher root mean square successive differences of normal-to-normal intervals [P=0.001]; higher normalized high-frequency power [P=0.008]; and lower low-frequency/high-frequency ratio [P=0.03]) and less erratic sinoatrial node firing (eg, lower Poincar{\'e} ratio [P=0.02] and higher short-term fractal scaling exponent [P=0.005]) but not measures of circadian fluctuations (eg, 24-hour standard deviation of normal-to-normal intervals). Findings were similar for estimated dietary consumption of marine omega-3 fatty acids. For magnitudes of observed differences in HRV comparing the highest to lowest category of fish intake, differences in relative risk of cardiac death during 10.8 years of follow-up ranged from 1.1\% (for difference in standard deviation of normal-to-normal intervals) to 5.9\% and 8.4\% (for differences in Poincar{\'e} ratio and short-term fractal scaling exponent) lower risk.

CONCLUSIONS: Habitual tuna/other fish and marine omega-3 consumption are associated with specific HRV components in older adults, particularly indices of vagal activity, baroreceptor responses, and sinoatrial node function. Cellular mechanisms and implications for clinical risk deserve further investigation.

}, keywords = {Aged, Aged, 80 and over, Animals, Cardiovascular Diseases, Cohort Studies, Cross-Sectional Studies, Electrocardiography, Fatty Acids, Omega-3, Female, Fishes, Heart Rate, Humans, Male, Risk Factors, Seafood, Tuna, United States}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.107.732826}, author = {Mozaffarian, Dariush and Stein, Phyllis K and Prineas, Ronald J and Siscovick, David S} } @article {1008, title = {Higher levels of inflammation factors and greater insulin resistance are independently associated with higher heart rate and lower heart rate variability in normoglycemic older individuals: the Cardiovascular Health Study.}, journal = {J Am Geriatr Soc}, volume = {56}, year = {2008}, month = {2008 Feb}, pages = {315-21}, abstract = {

OBJECTIVES: To explore the relationship between (1) insulin resistance and inflammation factors with (2) higher heart rate (HR) and lower heart rate variability (HRV) in normoglycemic older adults.

DESIGN: Cross-sectional population-based study.

PARTICIPANTS: Five hundred forty-five adults aged 65 and older with normoglycemia (fasting glucose <100 mg/dL) who participated in the Cardiovascular Health Study.

MEASUREMENTS: Serum levels of three inflammation proteins (C-reactive protein (CRP), interleukin 6 (IL-6), and fibrinogen); insulin resistance, quantified according to the homeostasis assessment model (HOMA-IR); HR; and four representative measures of HRV (the standard deviation of normal beat to beat intervals (SDNN), the root mean square of successive differences (rMSSD), very low frequency power (VLF), and the low- to high-frequency power ratio (LF/HF)) derived from 24-hour Holter recordings.

RESULTS: High CRP and IL-6 levels were associated with higher HR and lower SDNN and VLF after adjustment for multiple covariates, including HOMA-IR and clinical cardiovascular disease. High IL-6 was also associated with lower LF/HF. Significant univariate inverse relationships between HOMA-IR and HR and HRV were also found, but the strengths of these relationships were attenuated after adjustment for inflammation factors.

CONCLUSION: Increased levels of inflammation markers and HOMA-IR are associated with higher HR and lower HRV. These findings suggest that inflammation may contribute to the pathogenesis of cardiovascular autonomic decline in older adults.

}, keywords = {Aged, C-Reactive Protein, Cardiovascular Diseases, Cross-Sectional Studies, Electrocardiography, Ambulatory, Female, Fibrinogen, Heart Rate, Humans, Inflammation Mediators, Insulin Resistance, Interleukin-6, Male, Risk Factors}, issn = {1532-5415}, doi = {10.1111/j.1532-5415.2007.01564.x}, author = {Stein, Phyllis K and Barzilay, Joshua I and Chaves, Paulo H M and Traber, Jennifer and Domitrovich, Peter P and Heckbert, Susan R and Gottdiener, John S} } @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} } @article {1069, title = {Heart rate variability and its changes over 5 years in older adults.}, journal = {Age Ageing}, volume = {38}, year = {2009}, month = {2009 Mar}, pages = {212-8}, abstract = {

PURPOSE: to characterise the association between age, ageing and heart rate variability (HRV) in older individuals, 585 adults age >65 years with two 24-h Holter recordings in the Cardiovascular Health Study were studied.

METHODS: heart rate (HR), ventricular premature contractions (VPCs), atrial premature contractions (APCs), frequency-domain, ratio-based and non-linear HRV and heart rate turbulence (HRT) were examined cross-sectionally by 5-year age groups and prospectively over 5 years. Analyses adjusted for gender, lower versus elevated cardiovascular (CV) risk and for the change in CV risk.

RESULTS: HR declined, and VPCs and APCs increased per 5-year increase in age. Frequency-domain HRV decreased more at 65-69, less at 70-74 and minimally at > or =75 years, independent of CVD risk or change in CVD risk. Ratio and non-linear HRV continued to decline to > or =75 years old. Ratio HRV and HRT slope were more strongly related to CVD risk than frequency-domain HRV.

CONCLUSIONS: cardiac autonomic function, assessed by frequency-domain HRV, declines most at 65-70 and levels off at age >75. The decline is independent of CVD risk or change in CVD risk. Ratio-based and non-linear HRV and HRT slope continued to change with increasing age and were more closely related to CVD risk than frequency-domain HRV.

}, keywords = {Age Distribution, Aged, Aging, Atrial Premature Complexes, Autonomic Nervous System, Cardiovascular Diseases, Cross-Sectional Studies, Electrocardiography, Ambulatory, Female, Heart Rate, Humans, Hypertension, Male, Nonlinear Dynamics, Prevalence, Prospective Studies, Risk Factors, Ventricular Premature Complexes}, issn = {1468-2834}, doi = {10.1093/ageing/afn292}, author = {Stein, Phyllis K and Barzilay, Joshua I and Chaves, Paulo H M and Domitrovich, Peter P and Gottdiener, John S} } @article {1162, title = {Association of Holter-based measures including T-wave alternans with risk of sudden cardiac death in the community-dwelling elderly: the Cardiovascular Health Study.}, journal = {J Electrocardiol}, volume = {43}, year = {2010}, month = {2010 May-Jun}, pages = {251-9}, abstract = {

BACKGROUND: Sudden cardiac death (SCD) can be the first manifestation of cardiovascular disease. Development of screening methods for higher/lower risk is critical.

METHODS: The Cardiovascular Health Study is a population-based study of risk factors for coronary heart disease and stroke those 65 years or older. Forty-nine (of 1649) with usable Holters and in normal sinus rhythm had SCD during follow-up and were matched with 2 controls, alive at the time of death of the case and not experiencing SCD on follow-up. Univariate and multivariate conditional logistic regression determined the association of Holter-based information and SCD.

RESULTS: In univariate models, the upper half of ventricular premature contraction (VPC) counts, abnormal heart rate turbulence, decreased normalized low-frequency power, increased T-wave alternans (TWA), and decreased the short-term fractal scaling exponent (DFA(1)) were associated with SCD, but time domain heart rate variability was not. In multivariate models, the upper half of VPC counts (odds ratio [OR], 6.6) and having TWA of 37 muV or greater on channel 2 (OR, 4.8) were independently associated with SCD. Also, the upper half of VPC counts (OR, 6.9) and having a DFA(1) of less than 1.05 (OR, 5.0) were independently associated with SCD. When additive effects were explored, having both higher VPCs and higher TWA was associated with an OR of 8.2 for SCD compared with 2.6 for having either. Also, having both higher VPCs and lower DFA(1) was associated with an OR of 9.6 for SCD compared with 3.1 for having either.

CONCLUSIONS: Results support a potential role for 24-hour Holter recordings to identify older adults at increased or lower risk of SCD.

}, keywords = {Comorbidity, Coronary Artery Disease, Death, Sudden, Cardiac, Electrocardiography, Ambulatory, Female, Humans, Male, Prevalence, Prognosis, Reproducibility of Results, Risk Assessment, Risk Factors, Sensitivity and Specificity, Survival Analysis, Survival Rate, United States, Ventricular Premature Complexes}, issn = {1532-8430}, doi = {10.1016/j.jelectrocard.2009.12.009}, author = {Stein, Phyllis K and Sanghavi, Devang and Sotoodehnia, Nona and Siscovick, David S and Gottdiener, John} } @article {1216, title = {Autonomic nervous system dysfunction and inflammation contribute to the increased cardiovascular mortality risk associated with depression.}, journal = {Psychosom Med}, volume = {72}, year = {2010}, month = {2010 Sep}, pages = {626-35}, abstract = {

OBJECTIVE: To investigate prospectively whether autonomic nervous system (ANS) dysfunction and inflammation play a role in the increased cardiovascular disease (CVD)-related mortality risk associated with depression.

METHODS: Participants in the Cardiovascular Health Study (n = 907; mean age, 71.3 {\textpm} 4.6 years; 59.1\% women) were evaluated for ANS indices derived from heart rate variability (HRV) analysis (frequency and time domain HRV, and nonlinear indices, including detrended fluctuation analysis (DFA(1)) and heart rate turbulence). Inflammation markers included C-reactive protein, interleukin-6, fibrinogen, and white blood cell count). Depressive symptoms were assessed, using the 10-item Centers for Epidemiological Studies Depression scale. Cox proportional hazards models were used to investigate the mortality risk associated with depression, ANS, and inflammation markers, adjusting for demographic and clinical covariates.

RESULTS: Depression was associated with ANS dysfunction (DFA(1), p = .018), and increased inflammation markers (white blood cell count, p = .012, fibrinogen p = .043) adjusting for covariates. CVD-related mortality occurred in 121 participants during a median follow-up of 13.3 years. Depression was associated with an increased CVD mortality risk (hazard ratio, 1.88; 95\% confidence interval, 1.23-2.86). Multivariable analyses showed that depression was an independent predictor of CVD mortality (hazard ratio, 1.72; 95\% confidence interval, 1.05-2.83) when adjusting for independent HRV and inflammation predictors (DFA(1), heart rate turbulence, interleukin-6), attenuating the depression-CVD mortality association by 12.7\% (p < .001).

CONCLUSION: Autonomic dysfunction and inflammation contribute to the increased cardiovascular mortality risk associated with depression, but a large portion of the predictive value of depression remains unexplained by these neuroimmunological measures.

}, keywords = {Aged, Autonomic Nervous System Diseases, Biomarkers, C-Reactive Protein, Cardiovascular Diseases, Cause of Death, Cohort Studies, Comorbidity, Depressive Disorder, Electrocardiography, Female, Follow-Up Studies, Heart Rate, Humans, Inflammation, Interleukin-6, Leukocyte Count, Male, Risk Factors}, issn = {1534-7796}, doi = {10.1097/PSY.0b013e3181eadd2b}, author = {Kop, Willem J and Stein, Phyllis K and Tracy, Russell P and Barzilay, Joshua I and Schulz, Richard and Gottdiener, John S} } @article {1255, title = {Relationship of abnormal heart rate turbulence and elevated CRP to cardiac mortality in low, intermediate, and high-risk older adults.}, journal = {J Cardiovasc Electrophysiol}, volume = {22}, year = {2011}, month = {2011 Feb}, pages = {122-7}, abstract = {

INTRODUCTION: We examined whether heart rate turbulence (HRT) and C-reactive protein (CRP) add to traditional risk factors for cardiac mortality in older adults at low, intermediate, and high risk.

METHODS AND RESULTS: One thousand two hundred and seventy-two individuals, age >= 65 years, with 24-hour Holter recordings were studied. HRT, which quantifies heart rate response to ventricular premature contractions, was categorized as: both turbulence onset (TO) and turbulence slope (TS) normal; TO abnormal; TS abnormal; or both abnormal. Independent risks for cardiac mortality associated with HRT or, for comparison, elevated CRP (>3.0 mg/L), were calculated using Cox regression analysis adjusted for traditional cardiovascular disease risk factors and stratified by the presence of no, isolated subclinical (i.e., intermediate risk) or clinical cardiovascular disease. Having TS + TO abnormal compared to both normal was associated with cardiac mortality in the low-risk group [HR 7.9, 95\% confidence interval (CI) 2.8-22.5, (P < 0.001)]. In the high and intermediate risk groups, abnormal TS and TS + TO ([HR 2.2, 95\% CI 1.5-4.0, P = 0.016] and [HR 2.7, 95\% CI 1.2-5.9, P = 0.012]), respectively, were also significantly associated with cardiac mortality. In contrast, elevated CRP was associated with increased cardiac mortality risk only in low-risk individuals [HR 2.5, 95\% CI 1.3-5.1, P = 0.009]. Among low risk, the c-statistic was 0.706 for the base model, 0.725 for the base model with CRP, and 0.767 for the base model with HRT.

CONCLUSIONS: Abnormal HRT independently adds to risk stratification of low, intermediate and high-risk individuals, but HRT and CRP appear to both add to stratification of those considered low risk.

}, keywords = {Aged, C-Reactive Protein, Cardiovascular Diseases, Comorbidity, Electrocardiography, Ambulatory, Female, Humans, Incidence, Male, Risk Assessment, Risk Factors, Statistics as Topic, Survival Analysis, Survival Rate, United States, Ventricular Premature Complexes}, issn = {1540-8167}, doi = {10.1111/j.1540-8167.2010.01967.x}, author = {Stein, Phyllis K and Barzilay, Joshua I} } @article {1391, title = {Cardiovascular physiology in premotor Parkinson{\textquoteright}s disease: a neuroepidemiologic study.}, journal = {Mov Disord}, volume = {27}, year = {2012}, month = {2012 Jul}, pages = {988-95}, abstract = {

Changes in cardiovascular physiology in Parkinson{\textquoteright}s disease (PD) are common and may occur prior to diagnostic parkinsonian motor signs. We investigated associations of electrocardiographic (ECG) abnormalities, orthostasis, heart rate variability, and carotid stenosis with the risk of PD diagnosis in the Cardiovascular Health Study, a community-based cohort of older adults. ECG abnormality, orthostasis (symptomatic or asymptomatic), heart rate variability (24-hour Holter monitoring), and any carotid stenosis (>=1\%) by ultrasound were modeled as primary predictors of incident PD diagnosis using multivariable logistic regression. Incident PD cases were identified by at least 1 of the following: self-report, antiparkinsonian medication use, and ICD-9. If unadjusted models were significant, they were adjusted or stratified by age, sex, and smoking status, and those in which predictors were still significant (P <= .05) were also adjusted for race, diabetes, total cholesterol, low-density lipoprotein, blood pressure, body mass index, physical activity, education level, stroke, and C-reactive protein. Of 5888 participants, 154 incident PD cases were identified over 14 years of follow-up. After adjusting models with all covariates, those with any ECG abnormality (odds ratio [OR], 1.45; 95\% CI, 1.02-2.07; P = .04) or any carotid stenosis (OR, 2.40; 95\% CI, 1.40-4.09; P = .001) at baseline had a higher risk of incident PD diagnosis. Orthostasis and heart rate variability were not significant predictors. This exploratory study suggests that carotid stenosis and ECG abnormalities occur prior to motor signs in PD, thus serving as potential premotor features or risk factors for PD diagnosis. Replication is needed in a population with more thorough ascertainment of PD onset.

}, keywords = {Aged, Antiparkinson Agents, Cardiovascular Physiological Phenomena, Carotid Stenosis, Cohort Studies, Data Interpretation, Statistical, Dizziness, Electrocardiography, Female, Heart Rate, Hospitalization, Humans, Longitudinal Studies, Male, Movement Disorders, Neurologic Examination, Parkinson Disease, Risk, Ultrasonography}, issn = {1531-8257}, doi = {10.1002/mds.24979}, author = {Jain, Samay and Ton, Thanh G and Perera, Subashan and Zheng, Yan and Stein, Phyllis K and Thacker, Evan and Strotmeyer, Elsa S and Newman, Anne B and Longstreth, Will T} } @article {1393, title = {Heart rate response to a timed walk and cardiovascular outcomes in older adults: the cardiovascular health study.}, journal = {Cardiology}, volume = {122}, year = {2012}, month = {2012}, pages = {69-75}, abstract = {

OBJECTIVES: To determine the relationship between heart rate response during low-grade physical exertion (6-min walk) with mortality and adverse cardiovascular outcomes in the elderly.

METHODS: Participants in the Cardiovascular Health Study who completed a 6-min walk test were included. We used delta heart rate (difference between postwalk heart rate and resting heart rate) as a measure of chronotropic response and examined its association with (1) all-cause mortality and (2) incident coronary heart disease event, using multivariable Cox regression models.

RESULTS: We included 2,224 participants (mean age 77 {\textpm} 4 years; 60\% women; 85\% white). The average delta heart rate was 26 beats/min. Participants in the lowest tertile of delta heart rate (<20 beats/min) had higher risk-adjusted mortality [hazard ratio (HR) 1.18, 95\% confidence interval (CI) 1.00-1.40] and incident coronary heart disease (HR 1.37, 95\% CI 1.05-1.78) compared to subjects in the highest tertile (>=30 beats/min), with a significant linear trend across tertiles (p for trend <0.05 for both outcomes). This relationship was not significant after adjustment for distance walked.

CONCLUSION: Impaired chronotropic response during a 6-min walk test was associated with an increased risk of mortality and incident coronary heart disease among the elderly. This association was attenuated after adjusting for distance walked.

}, keywords = {Aged, Cause of Death, Coronary Disease, Exercise Test, Female, Heart Rate, Humans, Male, Physical Exertion, Prognosis, Prospective Studies, Risk Factors, Time Factors, Walking}, issn = {1421-9751}, doi = {10.1159/000338736}, author = {Girotra, Saket and Kitzman, Dalane W and Kop, Willem J and Stein, Phyllis K and Gottdiener, John S and Mukamal, Kenneth J} } @article {1397, title = {Trans-fatty acid consumption and heart rate variability in 2 separate cohorts of older and younger adults.}, journal = {Circ Arrhythm Electrophysiol}, volume = {5}, year = {2012}, month = {2012 Aug 01}, pages = {728-38}, abstract = {

BACKGROUND: Trans-fatty acid (TFA) consumption is associated with risk of coronary heart disease, and trans-18:2, but not trans-18:1, in red blood cell membranes has been associated with sudden cardiac arrest. Abnormal heart rate variability (HRV) reflects autonomic dysfunction and predicts cardiac death. Relationships between TFA consumption and HRV remain understudied. We determined whether total TFA consumption, as well as trans-18:1 and trans-18:2 TFA consumption, was independently associated with HRV in 2 independent cohorts in the United States and Portugal.

METHODS AND RESULTS: In 2 independent cohorts of older US adults (Cardiovascular Health Study [CHS], age 72{\textpm}5 years, 1989/1995) and young Portuguese adults (Porto, age 19{\textpm}2 years, 2008/2010), we assessed habitual TFA intake by food frequency questionnaires in CHS (separately estimating trans-18:1 and trans-18:2) and multiple 24-hour recalls in Porto (estimating total TFA only, which in a subset correlated with circulating trans-18:2 but not trans-18:1, suggesting that we captured the former). HRV was assessed using 24-hour Holters in CHS (n=1076) and repeated short-term (5-minute) ECGs in Porto (n=160). We used multivariate-adjusted linear regression to relate TFA consumption to HRV cross-sectionally (CHS, Porto) and longitudinally (CHS). In CHS, higher trans-18:2 consumption was associated with lower 24-hour SD of all normal-to-normal intervals both cross-sectionally (-12\%; 95\% CI, -19\% to -6\%; P=0.001) and longitudinally (-15\%; 95\% CI, -25\% to -4\%; P= 0.009) and lower 24-hour SD of 5-minute average N-N intervals and mean of the 5-minute SD of N-N intervals calculated over 24 hours (P<0.05 each). Higher trans-18:1 consumption in CHS was associated with more favorable 24-hour HRV in particular time-domain indices (24-hour SD of all normal-to-normal intervals, SD of 5-minute average N-N intervals, mean of the 5-minute SD of N-N intervals calculated over 24 hours; P<0.05 each). In Porto, each higher SD TFA consumption was associated with 4\% lower 5-minute 24-hour SD of all normal-to-normal intervals (95\% CI, -8\% to -1\%; P=0.04) and 7\% lower 5-minute square root of the mean of the squares of successive N-N differences (95\% CI, -13\% to -1\%; P=0.04).

CONCLUSIONS: Trans-18:2 consumption is associated with specific, less favorable indices of HRV in both older and young adults. Trans-18:1 consumption is associated with more favorable HRV indices in older adults. Our results support the need to investigate potential HRV-related mechanisms, whereby trans-18:2 may increase arrhythmic risk.

}, keywords = {Adolescent, Age Factors, Aged, Aging, Arrhythmias, Cardiac, Cohort Studies, Cross-Sectional Studies, Dietary Fats, Electrocardiography, Ambulatory, Feeding Behavior, Female, Heart Rate, Humans, Linear Models, Longitudinal Studies, Male, Multivariate Analysis, Portugal, Predictive Value of Tests, Prospective Studies, Risk Assessment, Risk Factors, Surveys and Questionnaires, Trans Fatty Acids, United States, Young Adult}, issn = {1941-3084}, doi = {10.1161/CIRCEP.111.966259}, author = {Soares-Miranda, Luisa and Stein, Phyllis K and Imamura, Fumiaki and Sattelmair, Jacob and Lemaitre, Rozenn N and Siscovick, David S and Mota, Jorge and Mozaffarian, Dariush} } @article {6166, title = {Atrial ectopy as a predictor of incident atrial fibrillation: a cohort study.}, journal = {Ann Intern Med}, volume = {159}, year = {2013}, month = {2013 Dec 03}, pages = {721-8}, abstract = {

BACKGROUND: Atrial fibrillation (AF) prediction models have unclear clinical utility given the absence of AF prevention therapies and the immutability of many risk factors. Premature atrial contractions (PACs) play a critical role in AF pathogenesis and may be modifiable.

OBJECTIVE: To investigate whether PAC count improves model performance for AF risk.

DESIGN: Prospective cohort study.

SETTING: 4 U.S. communities.

PATIENTS: A random subset of 1260 adults without prevalent AF enrolled in the Cardiovascular Health Study between 1989 and 1990.

MEASUREMENTS: The PAC count was quantified by 24-hour electrocardiography. Participants were followed for the diagnosis of incident AF or death. The Framingham AF risk algorithm was used as the comparator prediction model.

RESULTS: In adjusted analyses, doubling the hourly PAC count was associated with a significant increase in AF risk (hazard ratio, 1.17 [95\% CI, 1.13 to 1.22]; P < 0.001) and overall mortality (hazard ratio, 1.06 [CI, 1.03 to 1.09]; P < 0.001). Compared with the Framingham model, PAC count alone resulted in similar AF risk discrimination at 5 and 10 years of follow-up and superior risk discrimination at 15 years. The addition of PAC count to the Framingham model resulted in significant 10-year AF risk discrimination improvement (c-statistic, 0.65 vs. 0.72; P < 0.001), net reclassification improvement (23.2\% [CI, 12.8\% to 33.6\%]; P < 0.001), and integrated discrimination improvement (5.6\% [CI, 4.2\% to 7.0\%]; P < 0.001). The specificity for predicting AF at 15 years exceeded 90\% for PAC counts more than 32 beats/h.

LIMITATION: This study does not establish a causal link between PACs and AF.

CONCLUSION: The addition of PAC count to a validated AF risk algorithm provides superior AF risk discrimination and significantly improves risk reclassification. Further study is needed to determine whether PAC modification can prospectively reduce AF risk.

PRIMARY FUNDING SOURCE: American Heart Association, Joseph Drown Foundation, and National Institutes of Health.

}, keywords = {Aged, Atrial Fibrillation, Atrial Function, Cause of Death, Electrocardiography, Female, Humans, Male, Models, Statistical, Myocardial Contraction, Prospective Studies, Risk Assessment}, issn = {1539-3704}, doi = {10.7326/0003-4819-159-11-201312030-00004}, author = {Dewland, Thomas A and Vittinghoff, Eric and Mandyam, Mala C and Heckbert, Susan R and Siscovick, David S and Stein, Phyllis K and Psaty, Bruce M and Sotoodehnia, Nona and Gottdiener, John S and Marcus, Gregory M} } @article {6071, title = {Cardiomyocyte injury assessed by a highly sensitive troponin assay and sudden cardiac death in the community: the Cardiovascular Health Study.}, journal = {J Am Coll Cardiol}, volume = {62}, year = {2013}, month = {2013 Dec 03}, pages = {2112-20}, abstract = {

OBJECTIVES: This study sought to determine the association between markers of cardiomyocyte injury in ambulatory subjects and sudden cardiac death (SCD).

BACKGROUND: The pathophysiology of SCD is complex but is believed to be associated with an abnormal cardiac substrate in most cases. The association between biomarkers of cardiomyocyte injury in ambulatory subjects and SCD has not been investigated.

METHODS: Levels of cardiac troponin T, a biomarker of cardiomyocyte injury, were measured by a highly sensitive assay (hsTnT) in 4,431 ambulatory participants in the Cardiovascular Health Study, a longitudinal community-based prospective cohort study. Serial measures were obtained in 3,089 subjects. All deaths, including SCD, were adjudicated by a central events committee.

RESULTS: Over a median follow-up of 13.1 years, 246 participants had SCD. Baseline levels of hsTnT were significantly associated with SCD (hazard ratio [HR] for +1 log(hsTnT): 2.04, 95\% confidence interval [CI]: 1.78 to 2.34]. This association persisted in covariate-adjusted Cox analyses accounting for baseline risk factors (HR: 1.30, 95\% CI: 1.05 to 1.62), as well as for incident heart failure and myocardial infarction (HR: 1.26, 95\% CI: 1.01 to 1.57). The population was also categorized into 3 groups based on baseline hsTnT levels and SCD risk [fully adjusted HR: 1.89 vs. 1.55 vs. 1 (reference group) for hsTnT >=12.10 vs. 5.01 to 12.09 vs. <= 5.00 pg/ml, respectively; p trend = 0.005]. On serial measurements, change in hsTnT levels was also associated with SCD risk (fully adjusted HR for +1 pg/ml per year increase from baseline: 1.03, 95\% CI: 1.01 to 1.06).

CONCLUSIONS: The findings suggest an association between cardiomyocyte injury in ambulatory subjects and SCD risk beyond that of traditional risk factors.

}, keywords = {Aged, Ambulatory Care, Biomarkers, Death, Sudden, Cardiac, Female, Heart Arrest, Humans, Longitudinal Studies, Male, Middle Aged, Myocardium, Myocytes, Cardiac, Proportional Hazards Models, Risk Assessment, Troponin T}, issn = {1558-3597}, doi = {10.1016/j.jacc.2013.07.049}, author = {Hussein, Ayman A and Gottdiener, John S and Bartz, Traci M and Sotoodehnia, Nona and DeFilippi, Christopher and Dickfeld, Timm and Deo, Rajat and Siscovick, David and Stein, Phyllis K and Lloyd-Jones, Donald} } @article {6167, title = {Impact of inflammatory biomarkers on relation of high density lipoprotein-cholesterol with incident coronary heart disease: cardiovascular Health Study.}, journal = {Atherosclerosis}, volume = {231}, year = {2013}, month = {2013 Dec}, pages = {246-51}, abstract = {

BACKGROUND: Inflammatory factors and low HDL-C relate to CHD risk, but whether inflammation attenuates any protective association of high HDL-C is unknown.

OBJECTIVE: Investigate inflammatory markers{\textquoteright} individual and collective impact on the association of HDL-C with incident coronary heart disease (CHD).

METHODS: In 3888 older adults without known cardiovascular disease (CVD), we examined if the inflammatory markers C-reactive protein (CRP), interleukin-6 (IL-6), and lipoprotein-associated phospholipase A2 (Lp-PLA$_{2}$) modify the relation of HDL-C with CHD. HDL-C, CRP, IL-6, and Lp-PLA$_{2}$ values were grouped as using gender-specific tertiles. Also, an inflammation index of z-score sums for CRP, IL-6, and Lp-PLA$_{2}$ was categorized into tertiles. We calculated CHD incidence for each HDL-C/inflammation group and performed Cox regression, adjusted for standard CVD risk factors and triglycerides to examine the relationship of combined HDL-C-inflammation groups with incident events.

RESULTS: CHD incidence (per 1000 person years) was higher for higher levels of CRP, IL-6, and the index, and lower for higher levels of HDL-C. Compared to high HDL-C/low-inflammation categories (referent), adjusted HRs for incident CHD were increased for those with high HDL-C and high CRP (HR = 1.50, p < 0.01) or highest IL-6 tertile (HR = 1.40, p < 0.05), but not with highest Lp-PLA$_{2}$ tertile. Higher CHD incidence was similarly seen for those with intermediate or low HDL-C accompanied by high CRP, high IL-6, or a high inflammatory index.

CONCLUSION: The protective relation of high HDL-C for incident CHD appears to be attenuated by greater inflammation.

}, keywords = {1-Alkyl-2-acetylglycerophosphocholine Esterase, African Americans, Aged, Biomarkers, C-Reactive Protein, Cardiovascular Diseases, Cholesterol, HDL, Coronary Disease, European Continental Ancestry Group, Female, Humans, Incidence, Inflammation, Interleukin-6, Male, Middle Aged, Proportional Hazards Models, Prospective Studies, Risk Factors}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2013.08.036}, author = {Tehrani, David M and Gardin, Julius M and Yanez, David and Hirsch, Calvin H and Lloyd-Jones, Donald M and Stein, Phyllis K and Wong, Nathan D} } @article {5993, title = {Inflammation and sudden cardiac death in a community-based population of older adults: the Cardiovascular Health Study.}, journal = {Heart Rhythm}, volume = {10}, year = {2013}, month = {2013 Oct}, pages = {1425-32}, abstract = {

BACKGROUND: Inflammation is linked to adverse cardiovascular events, but its association with sudden cardiac death (SCD) has been controversial. Older subjects, who are at particular risk for SCD, were underrepresented in previous studies addressing this issue.

OBJECTIVE: The purpose of this study was to study the association between inflammation and SCD in a community-based population of older adults.

METHODS: In the Cardiovascular Health Study, 5806 and 5382 participants had measurements of C-reactive protein (CRP) and interleukin-6 (IL6), respectively, and were followed for up to 17 years. SCD risk as a function of baseline IL-6 and CRP was assessed in the overall population and in a group of participants without known prevalent cardiac disease.

RESULTS: In univariate analyses, both IL-6 (hazard ratio [HR] 1.79 for 1+ log IL-6, 95\% confidence interval [CI] 1.50-2.13; 5th vs 1st quintile HR 3.36, 95\% CI 2.24-5.05) and CRP (HR 1.31 for 1+ log CRP, 95\% CI 1.18-1.45; 5th vs 1st quintile HR 2.00, 95\% CI 1.40-2.87) were associated with SCD risk. In covariate-adjusted analyses, accounting for baseline risk factors, incident myocardial infarction, and heart failure, the association with SCD risk persisted for IL-6 (HR 1.26 for 1+ log IL-6, 95\% CI 1.02-1.56; 5th vs 1st quintile HR 1.63, 95\% CI 1.03-2.56) but was significantly attenuated for CRP (HR 1.13 for 1+ log CRP, 95\% CI 1.00-1.28; 5th vs 1st quintile HR 1.34, 95\% CI 0.88-2.05). Similar findings were observed in participants without prevalent cardiac disease.

CONCLUSION: Greater burden of inflammation, assessed by IL-6 levels, is associated with SCD risk beyond traditional risk factors, incident myocardial infarction, and heart failure.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Biomarkers, C-Reactive Protein, Case-Control Studies, Cohort Studies, Death, Sudden, Cardiac, Female, Humans, Inflammation, Interleukin-6, Male, Risk Factors}, issn = {1556-3871}, doi = {10.1016/j.hrthm.2013.07.004}, author = {Hussein, Ayman A and Gottdiener, John S and Bartz, Traci M and Sotoodehnia, Nona and DeFilippi, Christopher and See, Vincent and Deo, Rajat and Siscovick, David and Stein, Phyllis K and Lloyd-Jones, Donald} } @article {6361, title = {Physical activity and heart rate variability in older adults: the Cardiovascular Health Study.}, journal = {Circulation}, volume = {129}, year = {2014}, month = {2014 May 27}, pages = {2100-10}, abstract = {

BACKGROUND: Cardiac mortality and electrophysiological dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing the levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults.

METHODS AND RESULTS: We evaluated serial longitudinal measures of both physical activity and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard deviation of all normal-to-normal intervals (Ptrend=0.009, 0.02, 0.06, respectively) and ultralow-frequency power (Ptrend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with a higher short-term fractal scaling exponent (Ptrend=0.003) and lower Poincar{\'e} ratio (Ptrend=0.02), markers of less erratic sinus patterns.

CONCLUSIONS: Greater total leisure-time activity, and walking alone, as well, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual physical activity later in life.

}, keywords = {Aged, Cardiovascular Diseases, Cross-Sectional Studies, Electrocardiography, Ambulatory, Female, Follow-Up Studies, Health Status, Heart Rate, Humans, Leisure Activities, Longitudinal Studies, Male, Motor Activity, Prospective Studies, Walking}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.113.005361}, author = {Soares-Miranda, Luisa and Sattelmair, Jacob and Chaves, Paulo and Duncan, Glen E and Siscovick, David S and Stein, Phyllis K and Mozaffarian, Dariush} } @article {6668, title = {Association between left atrial abnormality on ECG and vascular brain injury on MRI in the Cardiovascular Health Study.}, journal = {Stroke}, volume = {46}, year = {2015}, month = {2015 Mar}, pages = {711-6}, abstract = {

BACKGROUND AND PURPOSE: Emerging evidence suggests that atrial disease is associated with vascular brain injury in the absence of atrial fibrillation.

METHODS: The Cardiovascular Health Study prospectively enrolled community-dwelling adults aged >=65 years. Among participants who underwent MRI, we examined associations of ECG left atrial abnormality with brain infarcts and leukoaraiosis. P-wave terminal force in lead V1 was the primary measure of left atrial abnormality; P-wave area and duration were secondary predictors. We excluded participants with atrial fibrillation before or on their index ECG. Primary outcomes were incident infarcts and worsening leukoaraiosis from initial to follow-up scan ≈5 years later. Secondary outcomes were prevalent infarcts and degree of leukoaraiosis on initial MRI. Relative risk (RR) and linear regression models were adjusted for vascular risk factors.

RESULTS: Among 3129 participants with >=1 scan, each SD increase in P-wave terminal force in lead V1 was associated with a 0.05-point (95\% confidence interval [CI], 0.0003-0.10) higher baseline white matter grade on a 10-point scale. P-wave terminal force in lead V1 was associated with prevalent infarcts of any type (RR per SD, 1.09; 95\% CI, 1.04-1.16) and more so with prevalent nonlacunar infarcts (RR per SD, 1.22; 95\% CI, 1.08-1.38). Among 1839 participants with 2 scans, P-wave terminal force in lead V1 was associated with worsening leukoaraiosis (RR per SD, 1.09; 95\% CI, 1.01-1.18), but not with incident infarcts (RR per SD, 1.06; 95\% CI, 0.93-1.20). Sensitivity analyses adjusting for incident atrial fibrillation found similar results. P-wave area and duration were not associated with outcomes.

CONCLUSIONS: ECG left atrial abnormality is associated with vascular brain injury in the absence of documented atrial fibrillation.

}, keywords = {Aged, Atrial Fibrillation, Brain, Brain Infarction, Cardiovascular Diseases, Cerebrovascular Trauma, Electrocardiography, Female, Heart Atria, Heart Diseases, Humans, Linear Models, Magnetic Resonance Imaging, Male, Middle Aged, Predictive Value of Tests, Prospective Studies, Regression Analysis, Risk Factors, Treatment Outcome}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.114.007762}, author = {Kamel, Hooman and Bartz, Traci M and Longstreth, W T and Okin, Peter M and Thacker, Evan L and Patton, Kristen K and Stein, Phyllis K and Gottesman, Rebecca F and Heckbert, Susan R and Kronmal, Richard A and Elkind, Mitchell S V and Soliman, Elsayed Z} } @article {6767, title = {Ventricular Ectopy as a Predictor of Heart Failure and Death.}, journal = {J Am Coll Cardiol}, volume = {66}, year = {2015}, month = {2015 Jul 14}, pages = {101-9}, abstract = {

BACKGROUND: Studies of patients presenting for catheter ablation suggest that premature ventricular contractions (PVCs) are a modifiable risk factor for congestive heart failure (CHF). The relationship among PVC frequency, incident CHF, and mortality in the general population remains unknown.

OBJECTIVES: The goal of this study was to determine whether PVC frequency ascertained using a 24-h Holter monitor is a predictor of a decrease in the left ventricular ejection fraction (LVEF), incident CHF, and death in a population-based cohort.

METHODS: We studied 1,139 Cardiovascular Health Study (CHS) participants who were randomly assigned to 24-h ambulatory electrocardiography (Holter) monitoring and who had a normal LVEF and no history of CHF. PVC frequency was quantified using Holter studies, and LVEF was measured from baseline and 5-year echocardiograms. Participants were followed for incident CHF and death.

RESULTS: Those in the upper quartile versus the lowest quartile of PVC frequency had a multivariable-adjusted, 3-fold greater odds of a 5-year decrease in LVEF (odds ratio [OR]: 3.10; 95\% confidence interval [CI]: 1.42 to 6.77; p = 0.005), a 48\% increased risk of incident CHF (HR: 1.48; 95\% CI: 1.08 to 2.04; p = 0.02), and a 31\% increased risk of death (HR: 1.31; 95\% CI: 1.06 to 1.63; p = 0.01) during a median follow-up of >13 years. Similar statistically significant results were observed for PVCs analyzed as a continuous variable. The specificity for the 15-year risk of CHF exceeded 90\% when PVCs included at least 0.7\% of ventricular beats. The population-level risk for incident CHF attributed to PVCs was 8.1\% (95\% CI: 1.2\% to 14.9\%).

CONCLUSIONS: In a population-based sample, a higher frequency of PVCs was associated with a decrease in LVEF, an increase in incident CHF, and increased mortality. Because of the capacity to prevent PVCs through medical or ablation therapy, PVCs may represent a modifiable risk factor for CHF and death.

}, keywords = {Aged, Catheter Ablation, Echocardiography, Electrocardiography, Ambulatory, Female, Forecasting, Heart Failure, Humans, Male, Risk Factors, Stroke Volume, Ventricular Premature Complexes}, issn = {1558-3597}, doi = {10.1016/j.jacc.2015.04.062}, author = {Dukes, Jonathan W and Dewland, Thomas A and Vittinghoff, Eric and Mandyam, Mala C and Heckbert, Susan R and Siscovick, David S and Stein, Phyllis K and Psaty, Bruce M and Sotoodehnia, Nona and Gottdiener, John S and Marcus, Gregory M} }