9 research outputs found

    Relation of Resting Heart Rate to Incident Atrial Fibrillation (from the Henry Ford Hospital Exercise Testing Project)

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    Autonomic nervous system (ANS) dysfunction plays a role in atrial fibrillation (AF) initiation. Cardiorespiratory fitness modulates ANS function and is inversely associated with resting heart rate (RHR) and risk of AF. Thus, we sought to study the association between RHR, as a surrogate for ANS function, and incident AF independent of exercise capacity (EC). We analyzed 51,436 subjects without previous AF who underwent a clinically indicated exercise stress test. Incident AF was ascertained through claims files. RHR was measured before stress testing, and EC was estimated by peak metabolic equivalents of task. We studied the association between RHR categories (85 beats/min) and incident AF using Cox models adjusted for risk factors and for EC. We tested for interaction between RHR and age, gender, smoking, and EC. Mean (SD) age was 53 (13) years, 53% were men, and 28% were black. Participants with RHR/min were older, more likely to be men, have higher EC, and more likely to smoke but less likely to have diabetes and hypertension. Over a median of 5.5 years, RHR/min was associated with 14% increased risk of AF (95 CI 6% to 25%) in fully adjusted models, whereas RHR \u3e85 beats/min was not associated with AF risk after adjusting for EC. Results for RHR analyzed continuously and by quartile were similar. No interaction was seen. In conclusion, subjects with low RHR at all levels of EC are at increased risk of AF and may benefit from heart rhythm surveillance, particularly in the presence of other AF risk factors

    The Association of Resting Heart Rate and Incident Hypertension: The Henry Ford Hospital Exercise Testing (FIT) Project

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    BACKGROUND: Given that sympathetic tone is associated with hypertension, we sought to determine whether resting heart rate (RHR), as a surrogate for cardiac autonomic function, was associated with incident hypertension. METHODS: We analyzed 21,873 individuals without a history of hypertension who underwent a clinically indicated exercise stress test. Baseline RHR was assessed prior to testing and was categorized as85 beats-per-minute (bpm). Incident hypertension was defined by subsequent diagnosis codes for new-onset hypertension from three or more encounters. We tested for effect modification by age (≥60 years), sex, race, and history of coronary heart disease (CHD). RESULTS: Mean (±SD) age was 49 (±12) years, 55% were men and 21% were Black. Compared to the lowest RHR (\u3c70 \u3ebpm) category, patients in the highest category (\u3e85 bpm) were younger, more likely to be female, heavier, diabetic, and achieve lower metabolic equivalents (METS). Over a median of 4 years follow-up, there were 8,179 cases of incident hypertension. Compared to RHR \u3c70 \u3ebpm, persons with RHR \u3e85 bpm had increased risk of hypertension after adjustment for CHD risk factors, baseline blood pressure (BP), and METS (hazard ratio = 1.15 (95% confidence interval 1.08-1.23)). Age was an effect modifier (interaction P = 0.02), whereas sex, race, and CHD were not. In age-stratified analyses the relationship remained significant only in those younger than 60 years. CONCLUSION: Elevated RHR is an independent risk factor for incident hypertension, particularly in younger persons. Whether lifestyle modification or other strategies to reduce RHR can prevent incident hypertension in high-risk individuals warrants further study

    Relation of Coronary Artery Calcium and Extra-Coronary Aortic Calcium to Incident Hypertension (from the Multi-Ethnic Study of Atherosclerosis).

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    Arterial calcification reflects an atherosclerotic process associated with vascular stiffness. Whether baseline coronary artery calcium (CAC) and extra-coronary calcium (ECC), measured using noncontrast computed tomography imaging, are associated with incident hypertension is poorly understood. We studied participants from the Multi-Ethnic Study of Atherosclerosis without measured or self-reported hypertension at baseline. Incident hypertension was defined by blood pressure criteria (BP, ≥140/90 mmHg), BP medication use, or both, and was assessed at in-person visits. We analyzed incident hypertension using multivariable-adjusted discrete-time proportional hazards models. Net reclassification improvement (NRI) assessed whether CAC reclassified hypertension risk when added to the Framingham hypertension risk score. Among 3,304 subjects analyzed, mean age was 59 ± 10 years; 48% were male and 42% were white. There were 1,283 incident hypertension cases over a median (interquartile range) follow-up time of 10.6 (4.5, 11.5) years. Each 1-unit increase in ln(CAC+1) was independently associated with a 12% higher risk of hypertension (95% confidence interval [CI] 9% to 16%). Relative to CAC = 0, patients with CAC >400 had a hazard ratio for incident hypertension of 2.2 (95% CI 1.8 to 2.9). There was no interaction by age, gender, or baseline BP (p = 0.43, 0.19, 0.09, respectively). Continuous NRI analyses demonstrated that CAC can reclassify risk of incident hypertension; NRI = 0.19 (95% CI 0.10 to 0.26). Furthermore, all measurements of ECC were significantly associated with incident hypertension, even after adjustment for CAC (hazard ratios ranging from 1.36 to 1.38). In conclusion, patients with CAC and ECC are at markedly higher risk of incident hypertension and may benefit from more intensified prevention efforts

    Comparison of the Relation of Carotid Intima-Media Thickness With Incident Heart Failure With Reduced Versus Preserved Ejection Fraction (from the Multi-Ethnic Study of Atherosclerosis [MESA])

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    Increased carotid intima-media thickness (cIMT) is associated with heart failure (HF) in previous studies, but it is not known whether the association of cIMT differs between HF with reduced (HFrEF) versus preserved ejection fraction (HFpEF). We studied 6699 participants (mean age 62 ± 10 years, 47% male, and 38% white) from the Multi-Ethnic Study of Atherosclerosis (MESA) with baseline cIMT measurements. We classified HF events as HFrEF (EF <50%) or HFpEF (EF ≥ 50%) at the time of diagnosis. Cox proportional hazard regression was used to compute hazard ratios (HR), and 95% confidence intervals (CI) for the association between the IMT Z-score (measured maximum IMT of Internal Carotid (IC) and Common Carotid (CC) sites as the mean of the maximum IMT of the near and far walls of right and left sides), and incident HFrEF or HFpEF. Models were adjusted for covariates and interim coronary artery disease (CAD) events. A total of 191 HFrEF and 167 HFpEF events occurred during follow-up. In multivariable analysis, each 1 standard deviation increase in the measured maximum IMT (Z-score) was associated with both HFrEF and HFpEF in the unadjusted and demographically adjusted models [HR, 95% CI 1.57 (1.43 to 1.73)] and [HR, 95% CI 1.61 (1.47 to 1.77)] but not in the fully adjusted models [HR, 95% CI 1.11 (0.96 to 1.28)] and [HR, 95% CI 1.13 (0.98 to 1.30)]. In conclusion, cIMT was significantly associated with incident HF, but the association is partially attenuated with adjustment for demographic factors and becomes non-significant after adjustment for other traditional heart failure risk factors and interim CAD events. There was no difference in the association of IMT measures with HFrEF versus HFpEF
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