Identification and management of the hypertensive patient with elevated heart rate: statement of a European Society of Hypertension Consensus Meeting

Effect of supervised exercise training on cardiovascular function in patients with intermittent claudication: a systematic review and meta-analysis of randomized controlled trials

This study aimed to determine the effect of supervised exercise training (SET) on cardiovascular function in patients with intermittent claudication (IC). A systematic search in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases was conducted. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), rate pressure product (RPP), cardiac output (CO), peak oxygen consumption (VO2peak), and heart rate variability (HRV). Secondary outcomes were maximum walking distance (MWD) and pain-free walking distance (PFWD). Outcomes were reported as weighted mean difference (WMD) between the SET group and the control group and synthesized by using the random-effects model. Seventeen RCTs with a total of 936 patients were included in this review. SET resulted in significant improvements of SBP (WMD =  - 7.40, 95% CI - 10.69 ~  - 4.11, p < 0.001, I2 = 15.2%), DBP (WMD =  - 1.92, 95% CI - 3.82 ~  - 0.02, p = 0.048, I2 = 0.0%), HR (WMD =  - 3.38, 95% CI - 6.30 ~  - 0.46, p = 0.023, I2 = 0.0%), RPP (WMD =  - 1072.82, 95% CI - 1977.05 ~  - 168.59, p = 0.020, I2 = 42.7%), and VO2peak with plantar flexion ergometer exercise (WMD = 5.57, 95% CI 1.66 ~ 9.49, p = 0.005, I2 = 62.4%), whereas CO and HRV remained statistically unaltered. SET also improved MWD (WMD = 139.04, 95% CI 48.64 ~ 229.44, p = 0.003, I2 = 79.3%) and PFWD (WMD = 40.02, 95% CI 23.85 ~ 56.18, p < 0.001, I2 = 0.0%). In conclusion, SET is effective in improving cardiovascular function in patients with IC, which was confirmed on outcomes of cardiovascular function associated with exercise ability. The findings hold out that the standard therapy of SET can improve not only walking distance but also cardiovascular function in patients with IC.

The Role of Heart Rate Variability (HRV) in Different Hypertensive Syndromes

Cardiac innervation by the parasympathetic nervous system (PNS) and the sympathetic nervous system (SNS) modulates the heart rate (HR) (chronotropic activity) and the contraction of the cardiac muscle (inotropic activity). The peripheral vasculature is controlled only by the SNS, which is responsible for peripheral vascular resistance. This also mediates the baroreceptor reflex (BR), which in turn mediates blood pressure (BP). Hypertension (HTN) and the autonomic nervous system (ANS) are closely related, such that derangements can lead to vasomotor impairments and several comorbidities, including obesity, hypertension, resistant hypertension, and chronic kidney disease. Autonomic dysfunction is also associated with functional and structural changes in target organs (heart, brain, kidneys, and blood vessels), increasing cardiovascular risk. Heart rate variability (HRV) is a method of assessing cardiac autonomic modulation. This tool has been used for clinical evaluation and to address the effect of therapeutic interventions. The present review aims (a) to approach the heart rate (HR) as a CV risk factor in hypertensive patients; (b) to analyze the heart rate variability (HRV) as a "tool" to estimate the individual risk stratum for Pre-HTN (P-HTN), Controlled-HTN (C-HTN), Resistant and Refractory HTN (R-HTN and Rf-HTN, respectively), and hypertensive patients with chronic renal disease (HTN+CKD).

Association between clustering of cardiovascular risk factors and resting heart rate in Chinese population: a cross-sectional study

BACKGROUND

Epidemiologic studies have explored the association between a single cardiovascular risk factor (CVRF) and resting heart rate (RHR), but the research on the relation of multiple risk factors with RHR remains scarce. This study aimed to explore the associations between CVRFs clustering and the risk of elevated RHR.

METHODS

In this cross-sectional study, adults aged 35-75 years from 31 provinces were recruited by the China PEACE Million Persons Projects from September 2015 to August 2020. We focused on seven risk factors: hypertension, diabetes mellitus, dyslipidemia, obesity, smoking, alcohol use, and low physical activity. Multivariate logistic regression was used to calculate odds ratios (OR) for elevated RHR (> 80 beats/min).

RESULTS

Among 1,045,405 participants, the mean age was 55.67 ± 9.86 years, and 60.4% of participants were women. The OR (95% CI) for elevated RHR for the groups with 1, 2, 3, 4 and ≥ 5 risk factor were 1.11 (1.08-1.13), 1.36 (1.33-1.39), 1.68 (1.64-1.72), 2.01 (1.96-2.07) and 2.58 (2.50-2.67), respectively (P _trend < 0.001). The association between the CVRFs clustering number and elevated RHR was much more pronounced in young males than in other age-sex subgroups. Clusters comprising more metabolic risk factors were associated with a higher risk of elevated RHR than those comprising more behavioral risk factors.

CONCLUSIONS

There was a significant positive association between the CVRFs clustering number and the risk of elevated RHR, particularly in young males. Compared clusters comprising more behavioral risk factors, clusters comprising more metabolic risk factors were associated with a higher risk of elevated RHR. RHR may serve as an indicator of the cumulative effect of multiple risk factors.

Effect of Presence versus Absence of Hypertension on Admission Heart Rate-Associated Cardiovascular Risk in Patients with Acute Coronary Syndrome

Background and Aims

Heart rate (HR) and hypertension are both important risk factors for adverse cardiovascular (CV) events in patients with established coronary artery disease (CAD). We sought to evaluate whether hypertension can modify the effect of admission HR on adverse CV events in patients with acute coronary syndrome (ACS).

Methods

A total of 1056 patients with ACS undergoing percutaneous coronary intervention (PCI) were analyzed. All patients were classified into three groups according to the tertiles of admission HR (T1: ≤66 bpm, n = 369; T2: 67–73 bpm, n = 322; and T3: ≥74 bpm, n = 365). The primary endpoint was defined as major adverse CV events (MACEs), including all-cause death, stroke, myocardial infarction, or unplanned repeat revascularization. The multivariate Cox regression model was performed to evaluate the association of admission HR with MACE stratified by hypertension.

Results

During the median follow-up of 30 months, a total of 232 patients developed at least one event. After adjusting for other covariates, elevated admission HR was significantly associated with an increased risk of MACE only in patients with hypertension (when T1 was taken as a reference, the adjusted HR of T2 was 1.143 [95% CI: 0.700–1.864] and that of T3 was 2.062 [95% CI: 1.300–3.270]); however, in patients without hypertension, admission HR was not associated with the risk of MACE (when T1 was taken as a reference, the adjusted HR of T2 was 0.744 [0.406–1.364] and that of T3 was 0.614 [0.342–1.101]) (P=0.025 for interaction).

Conclusions

In patients with ACS undergoing PCI, the association of elevated admission HR with an increased risk of MACE was present in individuals with hypertension but not in those without hypertension. This finding suggests a potential benefit of HR control for ACS patients when they concomitantly have hypertension.

Impact of resting heart rate on cardiovascular mortality according to serum albumin levels in a 24-year follow-up study on a general Japanese population: NIPPON DATA80

BackgroundElevated resting heart rate (RHR) is associated with an increased risk for cardiovascular disease (CVD) and all-cause mortality. However, the findings of cohort studies differed. Thus, the impact of RHR on CVD mortality might be different according to the background of the population. Therefore, we examined the relationship of RHR and CVD mortality according to serum ALB levels in a Japanese general population.MethodsIn total, 8363 individuals without a history of CVD were followed-up for 24.0 years. The participants were divided into four groups according to the quartiles of RHR (Q1-Q4), and they were further classified into the high and low ALB groups based on a median value of 44 g/L. We estimated the multivariable-adjusted hazard ratios (HRs) of CVD mortality in each RHR group based on ALB levels, and the interaction between RHR and ALB groups on CVD mortality was evaluated.ResultsWe found no significant association between RHR and CVD mortality. However, the Q4 of RHR was significantly associated with an increased risk for CVD mortality (HR: 1.27 [95% confidence interval, CI: 1.02-1.57]) in participants with a low ALB level. Meanwhile, the Q4 of RHR was significantly correlated with a decreased risk for CVD morality in those with a high ALB level (HR: 0.61 [95% CI: 0.47-0.79]) after adjusting for covariates. A significant interaction between RHR and ALB for CVD mortality was shown (p<0.001).ConclusionsThe impact of RHR on CVD mortality differed according to ALB levels in a general Japanese population.

Evaluation of elevated heart rate as a sympathetic nervous system biomarker in essential hypertension

BACKGROUND

There is a need for an easily accessible biomarker of sympathetic nervous activation in essential hypertension, but none exists. Heart rate (HR) has been suggested, but requires validation, now doubly important as an elevated HR in hypertension has emerged as an independent cardiovascular risk factor.

METHODS

Isotope dilution methodology was used to measure total and regional noradrenaline spillover and adrenaline secretion rates in 30 patients with unmedicated essential hypertension and in a comparator group of 48 healthy participants with normal blood pressure. The particular interest was in the relationship of measured HR to cardiac noradrenaline spillover, the measure of cardiac sympathetic activity.

RESULTS

Sympathetic activation was present in the patients with essential hypertension, evident in significantly increased mean cardiac, renal and total noradrenaline spillover rates. Adrenaline secretion was normal. HR in hypertension correlated directly with cardiac noradrenaline spillover (r = 0.82, P = 9.3 × 10), but not with renal noradrenaline spillover or adrenaline secretion. 67% of the variance in HR was attributable to differences in cardiac sympathetic activity. Among hypertensive patients there was no internal correlation between cardiac noradrenaline spillover, renal noradrenaline spillover and adrenaline secretion; the sympathetic activation commonly was not 'global'. In healthy participants HR did not correlate with measures of sympathetic activity or adrenaline secretion.

CONCLUSION

When sympathetic activation exists in essential hypertension it is differentiated, not necessarily involving all sympathetic outflows. An elevated HR proved to be a biomarker of cardiac sympathetic activation but not activation of the renal sympathetic outflow. Identifying activation of the cardiac sympathetic outflow as the prime mechanism of hypertension tachycardia is relevant to therapies which should now be considered to minimize cardiovascular risk in this clinical setting. Is an elevated HR a valid biomarker of sympathetic activation in essential hypertension? Yes, but only for the cardiac sympathetic outflow. The unavoidable principle is that regional differentiation of sympathetic responses in essential hypertension means that no simple test can ever represent each and every sympathetic outflow.

Association of Noise Annoyance with Measured Renal Hemodynamic Changes

BACKGROUND

Chronic mental stress is recognized as a modifiable risk factor for cardiovascular disease. The aim of this study was to demonstrate that noise annoyance-induced stress is associated with changes in renal hemodynamics.

METHODS

Renal hemodynamic parameters were measured using steady-state input clearance with infusion of para-aminohippuric acid and inulin in individuals with normal, high normal, and elevated blood pressure. All individuals ranked subjective annoyance due to noise in everyday life on a 7-grade Likert scale. The median of all rankings was used as a cutoff point to divide the group into noise-annoyed and non-noise-annoyed individuals. Different renal hemodynamic parameters were calculated based on the Gomez equation.

RESULTS

Noise-annoyed individuals (n = 58) showed lower renal plasma flow (599 ± 106 vs. 663 ± 124 mL/min, p = 0.009), lower renal blood flow (1,068 ± 203 vs. 1,172 ± 225 mL/min, p = 0.047), higher filtration fraction (22.7 ± 3.3 vs. 21.3 ± 3.0, p = 0.012), higher renal vascular resistance (88.9 ± 25.6 vs. 75.8 ± 22.9 mm Hg/[mL/min], p = 0.002), and higher resistance of afferent arteriole (2,439.5 ± 1,253.4 vs. 1,849.9 ± 1,242.0 dyn s-1 cm-5, p = 0.001) compared to non-noise-annoyed individuals (n = 55). There was no difference in measured glomerular filtration rate (133 ± 11.8 vs. 138 ± 15 mL/min, p = 0.181), resistance of efferent arteriole (2,419.4 ± 472.2 vs. 2,245.8 ± 370.3 dyn s-1 cm-5, p = 0.060), and intraglomerular pressure (64.0 ± 3.1 vs. 64.6 ± 3.5 mm Hg, p = 0.298) between the groups. After adjusting for age, renal plasma flow, renal blood flow, and renal vascular resistance remained significantly different between the groups, with a trend in increased afferent arteriolar resistance and filtration fraction.

CONCLUSION

In this study, noise annoyance was associated with reduced renal perfusion attributed to increased renal vascular resistance predominantly at the afferent site. Long-term consequences of this renal hemodynamic pattern due to noise annoyance need to be investigated.

Efficacy of dulaglutide on vascular health indexes in subjects with type 2 diabetes: a randomized trial

Background

Recent cardiovascular outcome trials have shown significant reductions in major cardiovascular (CV) events with glucagon-like peptide (GLP)-1 receptor agonists. Additionally, adjunctive surrogates for cardiovascular risk validated by some studies include arterial stiffness and endothelial function indexes. To date, no randomized trial has addressed the possible effects of antidiabetic interventional drugs such as GLP1 agonists on endothelial and arterial stiffness indexes as surrogate markers of vascular damage.

Aims

We aimed to evaluate metabolic efficacy and surrogate vascular efficacy endpoints of once-weekly dulaglutide (1.5 mg) plus traditional antidiabetic treatment compared with traditional antidiabetic treatment alone in subjects with type 2 diabetes.

Methods

Men and women (aged ≥ 50 years) with established or newly detected type 2 diabetes whose HbA1c level was 9.5% or less on stable doses of up to two oral glucose­ lowering drugs with or without basal insulin therapy were eligible for randomization. Subcutaneous dulaglutide was initiated at the full dose (1.5 mg/day weekly). Arterial stiffness (PWV: pulse wave velocity and augmentation index) and endothelial function (RHI: reactive hyperaemia index) were evaluated at baseline and at three-month and nine-month examination visits. At each visit (at 3 and 9 months), the subjects were also evaluated for glycaemic variables such as fasting plasma glucose (FPG) and HbA1c and lipid variables such as total cholesterol, LDL cholesterol, HDL cholesterol and triglyceride levels.

Results

At the three-month follow-up, the subjects treated with dulaglutide showed significantly lower serum levels of FPG and HbA1c than control subjects treated with conventional therapy. At the 9-month follow-up, subjects treated with dulaglutide showed significant lower values of the mean diastolic blood pressure, BMI, total serum cholesterol, LDL cholesterol, FPG, HbA1c and PWV and higher mean RHI values than control subjects treated with conventional therapy.

Conclusions

Our randomized trial showed that subjects with type 2 diabetes treated with conventional therapy plus 1.5 mg/day of subcutaneous dulaglutide compared with subjects treated with conventional therapy alone showed favourable metabolic effects associated with positive effects on vascular health markers such as arterial stiffness and endothelial function markers. These findings are consistent with previous study findings indicating the strict relationship between cardiovascular risk factors such as systolic blood pressure, total serum cholesterol and LDL levels and cardiovascular events and vascular health surrogate markers.

Diastolic blood pressure predicts outcomes after aortic paravalvular leak closure

OBJECTIVES

We sought to determine hemodynamic effects of aortic paravalvular leak (PVL) and predictors of clinical outcomes after aortic PVL closure.

BACKGROUND

The significance of hemodynamic alterations in PVL and relation to severity, procedural success of percutaneous closure and clinical outcomes have not been defined.

METHODS

Patients undergoing percutaneous PVL closure between July 21, 2004 and September 10, 2018 were included. PVL severity was assessed by echocardiography and aortic angiography. Hemodynamics were assessed by intra-arterial pressure tracings before and after PVL closure. The primary outcome was a composite of mortality, redo aortic valve replacement (AVR) and redo PVL closure.

RESULTS

One hundred and seventeen patients (mean age 70.3 ± 14.9 years, 79% surgical and 21% transcatheter prostheses) underwent PVL closure with 94% technical success. PVL was moderate or greater in 106 (91%) at baseline and 11 (11%) post-procedure. Diastolic BP for those with moderate or greater PVL was lower than for those with less PVL (50.3 ± 11.7 vs. 56.5 ± 12.4 mmHg, p < .001). Pulse pressure was similar between these groups (69.9 ± 20.3 vs. 67.4 ± 21.2 mmHg, p = .39). 35 patients (34%) had 40 events during a mean follow-up of 1.6 ± 1.9 years (23 deaths, 12 redo AVR, and five redo PVL closures). In a multivariate model, final diastolic BP <47 mmHg (HR 3.27 [1.45-7.36], p = .007) was a significant predictor of the composite endpoint.

CONCLUSIONS

Diastolic BP was significantly associated with aortic PVL severity and clinical outcomes after PVL closure. In contrast, pulse pressure did not correlate with PVL severity or outcomes. These findings have implications for clinical management of patients with aortic PVL.

Clinical factors associated with the intraventricular conduction disturbances in Swiss middle-aged adults: The CoLaus|PsyCoLaus study

BACKGROUND

Intraventricular conduction disturbances are associated with an increased risk of adverse cardiovascular outcomes. However, data about factors associated with intraventricular conduction disturbances are sparse. We aimed to identify the clinical factors associated with intraventricular conduction disturbances in the general population.

METHODS

Cross-sectional study in a sample of 3704 participants (age range 45-86 years, 55.2% women). Intraventricular conduction disturbances were defined as QRS > 110 ms on electrocardiograms, and classified into right bundle branch block (RBBB), left bundle branch block (LBBB), left anterior fascicular block (LAFB) and non-specific intraventricular conduction disturbances (NIVCD).

RESULTS

The number of participants, the resulting prevalence (square brackets) and 95% CI (round brackets) of intraventricular conduction disturbances and subtypes (RBBB, LBBB, LAFB and NIVCD) were 187 [5.1% (4.4-5.8%)], 103 [2.9%, (2.3-3.4%)], 29 [0.8% (0.6-1.1%)], 31 (0.9% [0.6-1.2%]), and 47 [1.3% (0.9-1.7)], respectively. Multivariable logistic regression identified male sex [odds ratio and (95% CI): 2.55 (1.34-4.86)] and increasing age (p-value for trend <0.001) as being associated with RBBB; hypertension [3.08 (1.20-7.91)] and elevated NT-proBNP [3.26 (1.43-7.41)] as being associated with LBBB; elevated NT-proBNP [3.14 (1.32-7.46)] as being associated with LFAB; and male sex [5.97 (1.91-18.7)] and increased height [1.31 (1.06-1.63)] as being associated with NIVCD.

CONCLUSION

In a sample of the Swiss middle-aged population, the clinical factors associated with intraventricular conduction disturbances differed according to the intraventricular conduction disturbances subtype: male sex and ageing for RBBB; hypertension and elevated NT-proBNP for LBBB; elevated NT-proBNP for LAFB; and male sex and increased height for NIVCD.

Differential Network Analysis Reveals Molecular Determinants Associated with Blood Pressure and Heart Rate in Healthy Subjects

There is mounting evidence that subclinical nonpathological high blood pressure and heart rate during youth and adulthood steadily increase the risk of developing a cardiovascular disease at a later stage. For this reason, it is important to understand the mechanisms underlying the subclinical elevation of blood pressure and heart rate in healthy, relatively young individuals. In the present study, we present a network-based metabolomic study of blood plasma metabolites and lipids measured using nuclear magnetic resonance spectroscopy on 841 adult healthy blood donor volunteers, which were stratified for subclinical low and high blood pressure (systolic and diastolic) and heart rate. Our results indicate a rewiring of metabolic pathways active in high and low groups, indicating that the subjects with subclinical high blood pressure and heart rate could present latent cardiometabolic dysregulations.

Sex-specific association of resting heart rate with type 2 diabetes mellitus

AIM

This study aimed to explore the association of resting heart rate (RHR) with type 2 diabetes mellitus (T2DM) by sex, and whether the association was mediated by insulin resistance (IR).

METHODS

This cross-sectional study enrolled 12,508 participants (median age 57 years), with information collection through questionnaire interview, anthropometric and laboratory measurements. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between RHR and T2DM by sex, and restricted cubic splines were used to describe the dose-response association. Mediation analysis was used to explore the contribution of IR, measured by homeostasis model assessment of insulin resistance (HOMA-IR) index, to RHR-related T2DM.

RESULTS

Among 12,508 participants, 1413 participants (11.30%) had T2DM. RHR was positively associated with T2DM (per 10-bpm increase in RHR, OR 1.48, 95% CI: 1.34-1.64 for men and OR 1.42, 95% CI: 1.32-1.52 for women). As compared with RHR = 75 bpm, with increasing RHR, the adjusted probability of T2DM was significantly increased for both men and women. HOMA-IR partially mediated the association (indirect effect: OR = 1.17, 95% CI:1.13-1.22; direct effect: OR = 1.25, 95% CI: 1.11-1.39 in men and indirect effect: OR = 1.16, 95% CI:1.13-1.20; direct effect: OR = 1.15, 95% CI: 1.15-1.35 in women).

CONCLUSION

RHR was significantly associated with T2DM, which suggests that RHR may be a non-invasive clinical marker of early intervention to prevent T2DM, and IR may partially mediated RHR-related T2DM.

The effect of acute, moderate intensity indoor cycling on the temporal resolution of human vision system, measured by critical fusion frequency

Critical fusion frequency (CFF) reflects the basic temporal function of the visual system and therefore is a good measure of its performance. CFF has been implemented in psychological and pharmacological studies to evaluate cognitive functions. The influence of abnormal environmental conditions, such as physical exercise, has been recently explored. Previous studies have presented alterations of cognitive processes due to acute exercise. However, the duration of the effect after the end of exercise has not been investigated. This evaluation is important especially in reference to long-term conclusions on the effect of training on CFF as an improvement of cognition. The main goal of this study was to check whether a stimulatory effect of acute submaximal physical exercise on CFF among non-experienced cyclists persists over time. Moreover, we asked whether this effect differs between areas of visual field. CFF thresholds from 15 volunteers were measured by means of an automated medical perimeter PTS 910 (Bogdani) before, immediately after the end, and 30 min after the end of two sessions (training and rest). During rest, CFF did not change significantly, but we observed an increased CFF immediately after training. Interestingly, this increase was maintained 30 min after the end of exercise in fovea. A greater decrease of CFF during rest was observed for lower than for upper hemifield. Our results suggest that an acute, moderate-intensity cycling improved CFF in non-experienced cyclists, with the duration of the effect depending on eccentricity. The possible visual hemifield asymmetries of CFF changes over time will be further investigated.

Monitoring exercise intensity in diabetes: applicability of "heart rate-index" to estimate oxygen consumption during aerobic and resistance training

PURPOSE

Accurate quantification and monitoring of exercise "dose", described by oxygen consumption (VO₂), is necessary for exercise prescription and individualization. However, due to the complexity and elevated cost of direct, gold-standard methods, this is rarely done outside research laboratories. Heart rate-index (HR_index) is a new simple method to estimate VO₂ in healthy and clinical populations. We tested the performance of HR_index to estimate VO₂ in diabetic patients during aerobic (AT) and isotonic training (IT).

METHODS

Data from 12 males (age: 64 ± 5 years; BMI: 26 ± 12) with type 2 diabetes were analysed. VO₂ and heart rate were measured during one AT and one IT session. Furthermore, VO₂ was indirectly estimated based on HR_index. Then, the correspondence between measured and estimated VO₂ was evaluated by two-way RM-ANOVA, correlation and Bland-Altman analysis.

RESULTS

Estimated average VO₂ values during AT (1292 ± 366 ml/min) were not different from (p = 0.243) and highly correlated with (r = 0.87, p < 0.001) the measured values (1369 ± 417 ml/min), with a small bias and imprecision. Conversely during IT, HR_index overestimated VO₂ compared to the actual measures (1048 ± 404 vs 667 ± 230 ml/min, p ≤ 0.001) and only a moderate correlation was found between values (r = 0.43, p ≤ 0.001), with a large bias and imprecision.

CONCLUSION

VO₂ of aerobic exercises can be accurately estimated in diabetes patients using HR_index. During isotonic exercise, this method is not recommended for monitoring metabolic intensity due to large overestimation and imprecision. In aerobic exercise, HR_index offers a simple and valid alternative to the direct VO₂ determination and may favour the applicability of time-resolved measures of exercise "dose".

Clinical determinants of the PR interval duration in Swiss middle-aged adults: The CoLaus/PsyCoLaus study

Background

Prolonged PR interval (PRi) is associated with adverse outcomes. However, PRi determinants are poorly known. We aimed to identify the clinical determinants of the PRi duration in the general population.

Hypothesis

Some clinical data are associated with prolonged PRi.

Methods

Cross‐sectional study conducted between 2014 and 2017. Electrocardiogram‐derived PRi duration was categorized into normal or prolonged (>200 ms). Determinants were identified using stepwise logistic regression, and results were expressed as multivariable‐adjusted odds ratio (OR) (95% confidence interval). A further analysis was performed adjusting for antiarrhythmic drugs, P‐wave contribution to PRi duration, electrolytes (kalemia, calcemia, and magnesemia), and history of cardiovascular disease.

Results

Overall, 3655 participants with measurable PRi duration were included (55.6% females; mean age 62 ± 10 years), and 330 (9.0%) had prolonged PRi. Stepwise logistic regression identified male sex (OR 1.41 [1.02‐1.97]); aging (65‐74 years: OR 2.29 [1.61‐3.24], and ≥ 75 years: OR 4.21 [2.81‐6.31]); increased height (per 5 cm, OR 1.15 [1.06‐1.25]); hypertension (OR 1.37 [1.06‐1.77]); and hs troponin T (OR 1.67 [1.15‐2.43]) as significantly and positively associated, and high resting heart rate (≥70 beats/min, OR 0.43 [0.29‐0.62]) as negatively associated with prolonged PRi. After further adjustment, male sex, aging and increased height remained positively, and high resting heart rate negatively associated with prolonged PRi. Hypertension and hs troponin T were no longer associated.

Conclusion

In a sample of the Swiss middle‐aged population, male sex, aging and increased height significantly increased the likelihood of a prolonged PRi duration, whereas a high resting heart rate decreased it.

Is the 10 metre walk test on sloped surfaces associated with age and physical activity in healthy adults?

Background

Preferred walking speed is considered an important indicator of health in older adults and is measured on level ground. However, this may not represent the complex demands of community ambulation such as walking on sloped surfaces. Performing a 10 m walk test on a sloped surface is a novel test, and may be a more sensitive measure of walking capacity which may better discriminate age or health-related changes in gait speed compared to a traditional level 10 m walk test. The purpose of this investigation was to determine healthy adults’ performance in the 10 m walk test across various inclines and speeds, and which version of the 10 m walk test would be best at discriminating age-related changes in walking speed. Further, this study aimed to determine whether measures of general health and physical activity are associated with the performance of each test.

Methods

Healthy Adults (n = 181) aged 20–80 years completed the 10 m walk test on level, downhill and uphill surfaces (8° inclination) at fastest and preferred speeds. Descriptive statistics were calculated for walking speed for males and females across each decade of life. Repeated measures ANOVA was performed to discriminate age-related changes in gait speed by decade, for the 10 m walk test at each speed and slope. Multiple linear regression analyses were conducted to examine the association between waist to height ratio, resting heart rate, age and self-reported physical activity upon preferred and fastest walking speeds at each incline (level/downhill/uphill).

Results

The 10 m walk test best discriminated age-related changes in gait speed when performed at fastest speeds on each slope, or at a preferred speed on an uphill slope. Waist to height ratio, age and the physical activity index were all significantly associated with fastest walking speeds over each incline and preferred uphill speed. Only waist to height ratio was associated with preferred walking speed on level and downhill surfaces.

Conclusions

The 10 m walk test has the greatest ability to discriminate age- and health-related changes in gait speed when it is performed at a fastest speed on any slope, or uphill at a preferred speed. The normative data reported in this study may be used to compare the performance of the 10 m walk test to that of healthy adults at preferred and fastest speeds on sloped surfaces.

Electronic supplementary material

The online version of this article (10.1186/s11556-019-0219-0) contains supplementary material, which is available to authorized users.

Independent and interactive associations of heart rate and body mass index or blood pressure with type 2 diabetes mellitus incidence: A prospective cohort study

AIMS/INTRODUCTION

An elevated heart rate has been reported to be associated with an increased incidence of type 2 diabetes mellitus. We investigated whether heart rate independently and interactively with body mass index or blood pressure was associated with the incidence of type 2 diabetes mellitus in a rural Chinese population.

MATERIALS AND METHODS

We measured the association between heart rate and type 2 diabetes mellitus in the Tongxiang China Kadoorie Biobank prospective cohort study using Cox proportional hazard models. Analyses included 53,817 participants without any history of diabetes, cancer, cardiovascular or rheumatic heart disease at baseline. Incident type 2 diabetes mellitus cases were identified through linkage with established Disease Registries and the China National Health Insurance System.

RESULTS

After a mean follow-up period of 6.9 years, 1,766 people had developed type 2 diabetes mellitus with an incidence of 4.75 per 1,000 person-years. Multivariable-adjusted hazard ratios and for type 2 diabetes mellitus across increasing quintiles of heart rate were 1.00 (reference), 1.24 (95% confidence interval [CI] 1.05-1.45), 1.21 (95% CI 1.03-1.41), 1.24 (95% CI 1.05-1.47) and 1.49 (95% CI 1.28-1.74), respectively, with a Ptrend  <0.001. This relationship was particularly evident among non-overweight/obese participants. A significant interaction between heart rate and body mass index on incident type 2 diabetes mellitus was observed with a P for interaction = 0.005.

CONCLUSIONS

Elevated heart rate is independently, in interaction with a higher body mass index, associated with a higher incidence of type 2 diabetes mellitus.

Elevated Blood Pressure in Adolescence Is Attributable to a Combination of Elevated Cardiac Output and Total Peripheral Resistance

Unlike in older people, it has been suggested that elevated blood pressure (BP) in young people is because of high cardiac output accompanied by normal total peripheral resistance (TPR)-a hyperkinetic/hyperdynamic circulation. We investigated this in a large, United Kingdom-based birth cohort of adolescents. The study was conducted on 2091 17-year-old participants in the ALSPAC (Avon Longitudinal Study of Parents and Children)-a prospective population-based birth cohort study. BP measurement and echocardiography were performed, and heart rate (HR), stroke volume (SV), and TPR were calculated. Data are means (SD). Higher quintiles of systolic BP were associated with higher SV, higher HR, and higher TPR. The proportional contribution made by SV, HR, and TPR to mean arterial pressure differed little by systolic BP quintile (SV [32%-34%], HR [25%-29%], and TPR [39%-41%]). Higher BP is attributable to a combination of higher cardiac output (ie, SV×HR) and higher TPR in a population-based sample of adolescents. There is no evidence of a disproportionate contribution from elevated cardiac output at higher BP levels.

6-year change in resting heart rate is associated with incident type 2 diabetes mellitus

BACKGROUND AND AIMS

Elevated resting heart rate (RHR) is associated with risk of type 2 diabetes mellitus (T2DM). However, the association of change in RHR (ΔRHR) and incident T2DM is not fully elucidated. We aimed to assess the dose-response association between 6-year ΔRHR and T2DM.

METHODS AND RESULTS

A total of 12155 non-T2DM participants ≥18 years old were enrolled during 2007-2008 and followed up during 2013-2014. ΔRHR was calculated by subtracting the baseline RHR from the RHR value at 6-year follow-up. Age-, sex-, and RHR-specific relative risks (RRs) and 95% confidence intervals (CIs) for the effect of ΔRHR on incident T2DM were calculated by using modified Poisson regression models. As compared with ΔRHR of 0 beats/min, the adjusted risk of T2DM was significantly increased with RHR increment and reduced with RHR reduction. ΔRHR was positively associated with future risk of T2DM [RR per unit increase: 1.03 (1.03-1.04)]. As compared with stable change in RHR group (-5<ΔRHR<5 beats/min), for ΔRHR ≤ -10 beats/min, -10<ΔRHR ≤ -5 beats/min, 5≤ΔRHR<10 beats/min, and ΔRHR ≥10 beats/min groups, the pooled adjusted RR (95% CI) of T2DM was 0.69 (0.55-0.86), 0.90 (0.73-1.11), 1.31 (1.07-1.61), and 1.90 (1.59-2.26), respectively. This significant association still existed on subgroup analyses based on age, sex, and baseline RHR and sensitivity analyses.

CONCLUSIONS

Dynamic RHR change was significantly associated with incident T2DM. Our study suggests that RHR may be a non-invasive clinical indicator for interventions aiming to reduce incident T2DM in the general population.

Exercise Prescription and Adherence for Breast Cancer: One Size Does Not FITT All

PURPOSE

To prospectively assess adherence to oncologist-referred, exercise programming consistent with current recommendations for cancer survivors among women with early breast cancer across the trajectory of adjuvant treatment.

METHODS

Sixty-eight women participated in supervised, hour-long, moderate-intensity, aerobic, and resistance exercise thrice per week during adjuvant chemotherapy ± radiation, with a step-down in frequency for 20 additional weeks. Adherence to exercise frequency (i.e., attendance), intensity, and time/duration, and barriers to adherence were tracked and compared during chemotherapy versus radiation, and during treatment (chemotherapy plus radiation, if received) versus after treatment.

RESULTS

Attendance decreased with cumulative chemotherapy dose (cycles 1-2 vs cycles 3-8, cycle 3 vs cycles 7-8, all P ≤ 0.05) and was lower during chemotherapy than radiation (64% ± 25% vs 71% ± 32%, P = 0.02) and after treatment than during treatment (P < 0.01). Adherence to exercise intensity trended toward being higher during chemotherapy than radiation (69% ± 23% vs 51% ± 38%, P = 0.06) and was higher during than after treatment (P = 0.01). Adherence to duration did not differ with treatment. Overall adherence to the resistance prescription was poor, but was higher during chemotherapy than radiation (57% ± 23% vs 34% ± 39%, P < 0.01) and was not different during than after treatment. The most common barriers to attendance during treatment were cancer-related (e.g., symptoms, appointments), and after treatment were life-related (e.g., vacation, work).

CONCLUSIONS

Adherence to supervised exercise delivered in a real-world clinical setting varies among breast cancer patients and across the treatment trajectory. Behavioral strategies and individualization in exercise prescriptions to improve adherence are especially important for later chemotherapy cycles, after treatment, and for resistance exercise.

A Longitudinal Study of the Association of Clinical Indices of Cardiovascular Autonomic Function with Breast Cancer Treatment and Exercise Training

BACKGROUND

Cardiovascular autonomic dysfunction is an early marker for cardiovascular disease. Anthracycline chemotherapy and left-sided radiation for breast cancer are associated with negative autonomic function changes. This study's objectives were to characterize changes in, and the association of exercise training with, clinical indices of cardiovascular autonomic function across the trajectory of breast cancer therapy.

SUBJECTS, MATERIALS, AND METHODS

Seventy-three patients receiving adjuvant chemotherapy participated to varying degrees in supervised aerobic and resistance exercise during chemotherapy ± radiation and for 20 weeks after. Resting heart rate (HR_rest) and blood pressure were measured weekly during chemotherapy. HR_rest, exercise heart rate recovery (HR_recovery), and aerobic fitness were measured at enrollment, end of chemotherapy ± radiation, and 10 and 20 weeks after treatment.

RESULTS

During chemotherapy, HR_rest increased in a parabolic manner within a single treatment and with increasing treatment dose, whereas systolic and diastolic blood pressure decreased linearly across treatments. Tachycardia and hypotension were present in 32%-51% of participants. Factors associated with weekly changes during chemotherapy included receiving anthracyclines or trastuzumab, days since last treatment, hematocrit, and exercise attendance. Receipt of anthracyclines, trastuzumab, and left-sided radiation individually predicted impairments of HR_rest and HR_recovery during chemotherapy ± radiation; however, aerobic fitness change and at least twice-weekly exercise attendance predicted improvement. By 10 weeks after treatment, HR_rest and blood pressure were not different from prechemotherapy.

CONCLUSION

In this study, chemotherapy resulted in increased HR_rest and tachycardia, as well as decreased blood pressure and hypotension. Anthracyclines, trastuzumab, and left-sided radiation were associated with HR_rest elevations and impairments of HR_recovery, but exercise training at least twice a week appeared to mitigate these changes.

IMPLICATIONS FOR PRACTICE

This study characterized changes in clinically accessible measures with well-established prognostic value for cardiovascular disease, and investigated associations with cardiotoxic treatments and the positive influence of exercise. The chemotherapy-related incremental increase in resting heart rate, with tachycardia occurring in one third of patients, and decrease in blood pressure, with hypotension occurring in one half of the patients, is relevant to oncology practitioners for clinical examination or patient report of related symptoms (i.e., dizziness). The weekly dose of two 60-minute sessions of moderate-intensity aerobic and resistance exercise that was identified as protective of cardiovascular autonomic impairments can easily be prescribed to patients by oncologists.

Persistent tachycardia in clozapine treated patients: A 24-hour ambulatory electrocardiogram study

Tachycardia is associated with cardiovascular mortality. Tachycardia is also a known clozapine adverse effect. However, whether clozapine-associated tachycardia is persistent is not known. Thirty clozapine-treated patients with clinical tachycardia were investigated with 24-hour ambulatory electrocardiography (ECG). Baseline peripheral heart rate (HR) was 106.7±7.8. The ambulatory ECG 24-hour-HR was 98.7±9.7. Baseline HR and 24-hour-HR correlated strongly (r=0.74, p=0.000003). Daytime HR was 106.4±9.9 and nighttime HR 89.2±12.0. Low dose bisoprolol reduced HR significantly. The high 24-hour-HR indicates a persistent tachycardia. Tachycardia should not discourage from clozapine use but the findings indicate a need of guidelines for detection and treatment of clozapine-associated tachycardia.

Resting heart rate, heart rate reserve, and metabolic syndrome in professional firefighters: A cross-sectional study

BACKGROUND

Little is known about the associations of resting heart rate (RHR) and heart rate reserve (HRR) with metabolic syndrome (MetS) in firefighters.

METHODS

For each of 288 professional firefighters, HRR was calculated as the difference between measured RHR and estimated maximum HR. For comparison, VO₂ max based on a treadmill test was included. MetS was defined according to the NCEP/ATP III criteria.

RESULTS

The prevalence of MetS was 14.2%. The average of RHR was 61.5 beat/min. Only 5.8% of the firefighters had RHR of ≥80 beat/min. Between the firefighters in the lowest and highest quintiles, the prevalence ratios (95% confidence intervals) for MetS were 1.88 (0.71-4.94), 5.90 (1.74-20.02), and 8.03 (1.86-34.75) for RHR, HRR, and VO₂ max, respectively. Both HRR and VO₂ max, but not RHR, were significantly associated with MetS and its most component risk factors in middle-aged firefighters.

CONCLUSIONS

HRR, a simple cardiovascular fitness measure, was inversely associated with MetS among middle-aged professional firefighters.

Management of the hypertensive patient with elevated heart rate: Statement of the Second Consensus Conference endorsed by the European Society of Hypertension

In June 2015, a panel of experts gathered in a consensus conference to plan updating recommendations on the management of the hypertensive patient with elevated heart rate (HR), previously released in 2006. The issues examined during that meeting and further discussed by the participants during the following months involved the assessment of HR, the relevance of HR as a cardiovascular risk factor, the definition of tachycardia and the treatment of the hypertensive patient with high HR. For the measurement of resting HR the panel experts recommended that scientific investigations focusing on HR should report information on length of resting period before measurement, information about temperature and environment, method of measurement, duration of measurement, number of readings, time interval between measurements, body position and type of observer. According to the panellists there is convincing evidence that HR is an important risk factor for cardiovascular disease and they suggest to routinely include HR measurement in the assessment of the hypertensive patient. Regarding the definition of tachycardia, the panellists acknowledged that in the absence of convincing data any threshold used to define tachycardia is arbitrary. Similarly, as there are no outcome studies of HR lowering in tachycardia hypertension, the panellists could not make practical therapeutic suggestions for the management of such patients. However, the experts remarked that absence of evidence does not mean evidence against the importance of tachycardia as a risk factor for cardiovascular disease and that long-term exposure to a potentially important risk factor may impair the patient's prognosis. The main aims of the present document are to alert researchers and physicians about the importance of measuring HR in hypertensive patients, and to stimulate research to clarify unresolved issues.

Associations between CD36 gene polymorphisms, fat tolerance and oral fat preference in a young-adult population

BACKGROUND/OBJECTIVES

CD36 is known to be an orosensory receptor for dietary long-chain fatty acids, as well as being involved in the chemosensory mechanisms within the human gut. Recent data have demonstrated an association between CD36 single-nucleotide polymorphisms (SNPs) and lipid consumption behaviours in humans. This study aimed to test for associations between CD36 SNPs and response to a high-fat meal in a young healthy Australian cohort. Secondary associations were tested between CD36 gene variants and fasting lipid parameters, body composition, cardiovascular disease (CVD) risk factors and measures of oral fat preference.

SUBJECTS/METHODS

Two SNPs (rs1527479 and rs1984112) were assessed for associations with response to a 75 g saturated fat oral fat tolerance test (OFTT), whole-body substrate oxidation, fasting plasma lipids, CVD risk factors and self-reported habitual diet questionnaires. Genotyping was performed using real-time polymerase chain reaction.

RESULTS

Cross-sectional data were collected on 56 individuals (28 m, 28 f; 24.9±3.3 years), with 42 completing participation in a high-fat OFTT. No genotypic associations were evident in anthropometric data or self-reported fat preference measures. AA SNP carriers at rs1984112 exhibited significantly elevated fasting triglyceride when compared with non-carriers (P=0.024). This group also tended to have an elevated response to a high-fat meal (P=0.078).

CONCLUSIONS

Although these data show the potential pleiotropic influence of CD36 SNP rs1984112 on lipoprotein accumulation in a young healthy cohort, further assessment in a larger cohort is warranted.

Relation of Birth Weight to Heart Rate in Childhood, Adolescence, and Adulthood (from the Bogalusa Heart Study)

Low birth weight is associated with cardiovascular disease and its risk factors in adulthood. However, information is limited regarding its impact on heart rate (HR), an established risk factor for cardiovascular disease. This study assessed the hypothesis that birth weight is associated with HR at rest at different ages. The study sample consisted of 6,282 black and white participants enrolled in the Bogalusa Heart Study, aged 4 to 52 years with a mean age of 19.4 years. HR data at rest were available in 2,344 children (4 to 11 years old), 1,622 adolescents (12 to 19 years old), and 2,316 adults (20 to 52 years old). Birth certificate records, including information on birth weight and gestational age, were obtained from the Louisiana State Office of Public Health. HR showed a significant decreasing trend with increasing age, with blacks having a lower slope than whites. In multivariable linear regression analyses, adjusted for age, race, gender, body mass index, and gestational age, the association between lower birth weight (kg) and increased HR (beats/min) was significant in adults (regression coefficient, β = -1.21, p = 0.006) but not significant in children (β = -0.31, p = 0.461) and adolescents (β = -0.72, p = 0.157). The association did not differ significantly between races. The birth weight-HR association did not change markedly in the models without adjustment for body mass index. In conclusion, these results suggest that the association of prenatal growth retardation with increased cardiovascular disease risk in later life might be partly through its relation with HR at rest.

Association of resting heart rate and hypertension stages on all-cause and cardiovascular mortality among elderly Koreans: the Kangwha Cohort Study

Background

Elevated resting heart rate and hypertension independently increase the risk of mortality. However, their combined effect on mortality in stages of hypertension according to updated clinical guidelines among elderly population is unclear.

Methods

We followed a cohort of 6100 residents (2600 males and 3500 females) of Kangwha County, Korea, ranging from 55 to 99 year-olds as of March 1985, for all-cause and cardiovascular mortality for 20.8 years until December 31, 2005. Mortality data were collected through telephone calls and visits (to 1991), and were confirmed by death record matching with the National Statistical Office (1992−2005). Hazard ratios were calculated for all-cause and cardiovascular mortality by resting heart rate and hypertension defined by Eighth Joint National Committee criteria using the Cox proportional hazard model after controlling for confounding factors.

Results

The hazard ratios associated with resting heart rate > 80 beats/min were higher in hypertensive men compared with normotensives with heart rate of 61–79 beats/min, with hazard ratios values of 1.43 (95% CI: 1.00−1.92) on all-cause mortality for prehypertension, 3.01 (95% CI: 1.07–8.28) on cardiovascular mortality for prehypertension, and 8.34 (95% CI: 2.52−28.19) for stage 2 hypertension. Increased risk (HR: 3.54, 95% CI: 1.16–9.21) was observed among those with both a resting heart rate ≥ 80 beats/min and prehypertension on cardiovascular mortality in women.

Conclusions

Individuals with coexisting elevated resting heart rate and hypertension, even in prehypertension, have a greater risk for all-cause and cardiovascular mortality compared to those with elevated resting heart rate or hypertension alone. These findings suggest that elevated resting heart rate should not be regarded as a less serious risk factor in elderly hypertensive patients.

Elevated heart rate and nondipping heart rate as potential targets for melatonin: a review

Elevated heart rate is a risk factor for cardiovascular and all-cause mortalities in the general population and various cardiovascular pathologies. Insufficient heart rate decline during the night, that is, nondipping heart rate, also increases cardiovascular risk. Abnormal heart rate reflects an autonomic nervous system imbalance in terms of relative dominance of sympathetic tone. There are only a few prospective studies concerning the effect of heart rate reduction in coronary heart disease and heart failure. In hypertensive patients, retrospective analyses show no additional benefit of slowing down the heart rate by beta-blockade to blood pressure reduction. Melatonin, a secretory product of the pineal gland, has several attributes, which predict melatonin to be a promising candidate in the struggle against elevated heart rate and its consequences in the hypertensive population. First, melatonin production depends on the sympathetic stimulation of the pineal gland. On the other hand, melatonin inhibits the sympathetic system in several ways representing potentially the counter-regulatory mechanism to normalize excessive sympathetic drive. Second, administration of melatonin reduces heart rate in animals and humans. Third, the chronobiological action of melatonin may normalize the insufficient nocturnal decline of heart rate. Moreover, melatonin reduces the development of endothelial dysfunction and atherosclerosis, which are considered a crucial pathophysiological disorder of increased heart rate and pulsatile blood flow. The antihypertensive and antiremodeling action of melatonin along with its beneficial effects on lipid profile and insulin resistance may be of additional benefit. A clinical trial investigating melatonin actions in hypertensive patients with increased heart rate is warranted.

Pulse contour cardiac output monitoring in acute heart failure patients : Assessment of hemodynamic measurements

Background

Heart failure is known to be a major public health problem. Fluid redistribution contributes to acute heart failure; therefore, knowledge of hemodynamic parameters could be important for optimizing outcomes. The pulse contour cardiac output monitor PiCCO uses the single thermal indicator technique and pulse contour analysis to calculate hemodynamic parameters of preload, afterload, cardiac output, systemic vascular resistance and extravascular lung water.

Objectives

We primarily aimed to describe values and parameters seen in acute heart failure patients admitted to the intensive care unit (ICU) and secondly to investigate associations between hemodynamic measurements and survival data.

Material and methods

In this study 420 consecutive patients admitted to a tertiary medical university hospital ICU between January 2004 and December 2009 were retrospectively investigated. The study sample was divided into two subgroups: patients monitored by PiCCO (n = 47) and those not monitored by thermodilution measurements (n = 373). No predetermined treatment algorithm based on knowledge obtained by the PiCCO monitor was used and measurements were individually interpreted by the treating physician. The PiCCO monitor measurements were carried out according to manufacturer’s directions.

Results

Patients with PiCCO monitoring were clinically in poorer health with a mean simplified acute physiology score II (SAPS2) of 45 ± 17 vs. 56 ± 20 (p < 0.01). The ICU mortality (22 % vs. 38 %, p = 0.02) and, at least as a tendency, long-term-mortality were increased in patients monitored by PiCCO (RR 1.49, 95 % CI 0.96–2.31, p = 0.08). We provide hemodynamic measurements in acute heart failure patients: cardiac index (2.7 ± 1.2 l/min/m²) was reduced, preload and extravascular lung water index (EVLWI, 11.5 ± 5.1 ml/kg body weight), representing lung edema, were increased.

Conclusion

We provide real world values for PiCCO parameters in acutely decompensated heart failure. In our study patients who were clinically in poorer health were monitored with PiCCO, resulting in increased mortality in this group. Further prospective studies to investigate the effects of treatment decisions triggered by information obtained by PiCCO monitoring for patients in acute heart failure are needed.

Associations between CD36 gene polymorphisms and metabolic response to a short-term endurance-training program in a young-adult population

Recent studies have shown that CD36 gene variants are associated with an increased prevalence of chronic disease. Although a genetic component to trainability has been proven, no data are available specifically on the influence of CD36 on training response. Two single nucleotide polymorphisms (SNPs) (rs1527479 and rs1984112) were assessed for associations with whole-body substrate oxidation, response to a 75-g dextrose oral glucose tolerance test, fasting plasma lipids, and cardiovascular disease risk factors in a young healthy cohort, both using cross-sectional analysis and following a 4-week endurance-exercise training program. Genotyping was performed using real-time polymerase chain reaction. Cross-sectional data were collected in 34 individuals (age, 22.7 ± 3.5 years), with 17 completing the training program. At baseline, TT SNP carriers at rs1527479 and wild-type GG carriers at rs1984112 were associated with significantly greater whole-body rate of fat oxidation (Fatox) during submaximal exercise (P < 0.05), whilst AA carriers at the same position were associated with elevated triglyceride (TG) levels. A significant genotype × time interaction in Fatox at SNP rs1984112 was identified at rest. Significant genotype × time interactions were present at rs1527479, with TT carriers exhibiting a favourable response to training when compared with C-allele carriers for fasting TG, diastolic blood pressure (DBP), and mean arterial pressure (MAP). In conclusion, cross-sectional assessment identified associations with Fatox and TG. Training response at both SNPs identified "at-risk" genotypes responding favourably to the training stimulus in Fatox, TG, DBP, and MAP. Although these data show potential pleiotropic influence of CD36 SNPs, assessment in a larger cohort is warranted.

Correlation between beat-to-beat blood pressure variability and arterial stiffness in healthy adults in the cold pressor test

Blood pressure variability has a great effect on the progression of arterial stiffness, which has increasingly become a hot research topic recently. In this study, beat-to-beat recordings of blood pressure (BP), heart rate, cardiac output, total peripheral resistance, and left ventricular ejection time during the cold pressor test (CPT) were analyzed together. We recruited 101 young Chinese subjects (aged 21-33) with no known history of high BP into the study. We found that the mean level of beat-to-beat BP and the average real variability and successive variation of beat-to-beat diastolic BP variability in the CPT showed significant correlations with pulse wave velocity (PWV) (r = 0.22-0.34, P < 0.05). In addition, we also found correlations between beat-to-beat heart rate and heart rate variability indices and PWV in each phase of the CPT. At the same time, the standard deviation of the R-R intervals and square root of the mean squared difference of successive R-R intervals in the cold stimulus phase also showed significant correlations with PWV (r = 0.23-0.24, P < 0.05). In conclusion, the level and variability of beat-to-beat BP have a strong influence on arterial stiffness.

Heart Rate, Life Expectancy and the Cardiovascular System: Therapeutic Considerations

It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed.

[Relationship between blood pressure, heart rate and cardiac autonomic dysfunction in non-diabetic obese patients]

RATIONALE

Some studies suggest that a high heart rate (HR) would be predictive of the incidence of an elevated blood pressure (BP). Cardiac autonomic dysfunction (CAD) affects a high proportion of obese patients. CAD could be involved in BP increase. Our aim was to examine the relationship between CAD, HR and BP in obese patients without known diabetes.

PATIENTS AND METHODS

We included 428 overweight or obese patients. CAD was assessed by analyzing HR variations during three standard tests (Valsalva, deep breathing, lying-to-standing), which are mostly dependent on vagal control. An oral load in glucose was performed and the Matsuda index was calculated.

RESULTS

The population was separated in 4 groups according to the grade of CAD (no or only one abnormal test, 2 or 3 abnormal tests) and HR (< or ≥ 75 bpm). Age was similar in the four groups. Systolic (P=0.05), diastolic (P<0.005) and mean BP (P<0.001) differed significantly between the 4 groups, and was the highest in the group of patients who had 2 or 3 abnormal tests and HR ≥ 75 bpm. Matsuda index differed across the groups (P=0.018) and was the lowest in this group.

CONCLUSION

These data indicate that among overweight or obese patients with a defect in cardiac vagal activity BP is elevated only in those with a high heart rate, which is indicative of a more marked insulin resistance and probably an excess in sympathetic activity.

Refractory Hypertension: Evidence of Heightened Sympathetic Activity as a Cause of Antihypertensive Treatment Failure

Refractory hypertension is an extreme phenotype of treatment failure defined as uncontrolled blood pressure in spite of ≥5 classes of antihypertensive agents, including chlorthalidone and a mineralocorticoid receptor antagonist. A prospective evaluation of possible mechanisms of refractory hypertension has not been done. The goal of this study was to test for evidence of heightened sympathetic tone as indicated by 24-hour urinary normetanephrine levels, clinic and ambulatory heart rate (HR), HR variability, arterial stiffness as indexed by pulse wave velocity, and systemic vascular resistance compared with patients with controlled resistant hypertension. Forty-four consecutive patients, 15 with refractory and 29 with controlled resistant hypertension, were evaluated prospectively. Refractory hypertensive patients were younger (48±13.3 versus 56.5±14.1 years; P=0.038) and more likely women (80.0 versus 51.9%; P=0.047) compared with patients with controlled resistant hypertension. They also had higher urinary normetanephrine levels (464.4±250.2 versus 309.8±147.6 µg per 24 hours; P=0.03), higher clinic HR (77.8±7.7 versus 68.8±7.6 bpm; P=0.001) and 24-hour ambulatory HR (77.8±7.7 versus 68.8±7.6; P=0.0018), higher pulse wave velocity (11.8±2.2 versus 9.4±1.5 m/s; P=0.009), reduced HR variability (4.48 versus 6.11; P=0.03), and higher systemic vascular resistance (3795±1753 versus 2382±349 dyne·s·cm(5)·m(2); P=0.008). These findings are consistent with heightened sympathetic tone being a major contributor to antihypertensive treatment failure and highlight the need for effective sympatholytic therapies in patients with refractory hypertension.

The association between resting heart rate and blood pressure among children and adolescents with different waist circumferences

Resting heart rate (RHR) is an accessible index of sympathetic activity. The objective of this study was to assess the associations between blood pressure (BP) and RHR in children with different waist circumferences (WCs). The data of the Chinese National Survey on Students' Constitution and Health in 2010 were used. A total of 91,762 participates aged 9 to 18 years with complete records were included. RHR was categorised into quintile groups and WC was stratified into small (<-1.035), medium (≥-1.035 and <1.035) and large (≥1.035) groups respectively, after they were converted into age- and sex-specific z-score. Multivariate linear regression revealed that the association between RHR z-score and BP was similar before and after WC was adjusted for. With 1 standard deviation variation in RHR, BP changed from 2.22 (95 % confidence interval (CI): 1.51, 2.93) to 3.58 mmHg (95 % CI: 2.54, 4.62) in small WC group and 1.83 (95 % CI: 1.10, 2.56) to 4.23 mmHg (95 % CI: 3.38, 5.09) in large WC group respectively.

CONCLUSIONS

This study revealed that BP was positively associated with RHR among children with different WCs, which implied the positive association between sympathetic activity and BP in children regardless of the amount of abdominal fat.

Clinic and ambulatory heart rates in patients with ischaemic heart disease and/or chronic heart failure taking rate-limiting medications: are they interchangeable?

BACKGROUND

The prognostic benefit from heart rate (HR) reduction in patients with ischaemic heart disease (IHD) and/or chronic heart failure (CHF) is now firmly established. Most decisions regarding initiation and/or dose adjustment of HR-limiting medications in such patients are based on clinic HR. Yet, this is a highly variable parameter that may not necessarily reflect HR control over the 24 h period.

OBJECTIVE

To examine the level of agreement between mean clinic and mean ambulatory HRs in patients with IHD and/or CHF taking rate-limiting medications.

METHODS

Prospective, observational study. Fifty patients with IHD and/or CHF who attended cardiology outpatient clinics at the Manchester Heart Centre and underwent same-day 24 h continuous ECG recording between March and October 2013 were included in the study. Mean clinic HR was compared with mean 24 h, daytime and night-time HRs. Limits-of-agreement plots were constructed to examine the relationship between the two HR measures in more detail.

RESULTS

The mean clinic HR was numerically similar to the mean HRs of all ambulatory time periods examined. However, on Bland-Altman plots, the limits of agreement between clinic and ambulatory HR means were quite wide, with the mean clinic HR ranging between 10.93 and 13.58 bpm below and 8.4 and 18.15 bpm above the mean ambulatory HR.

CONCLUSIONS

Although numerically similar, the means of clinic and ambulatory HRs in patients with IHD and/or CHF display wide limits of agreement. As such, the two measures cannot be regarded as interchangeable.

Variation in resting heart rate over 4 years and the risks of myocardial infarction and death among older adults

OBJECTIVE

Resting heart rate (RHR) is an established predictor of myocardial infarction (MI) and mortality, but the relationship between variation in RHR over a period of several years and health outcomes is unclear. We evaluated the relationship between long-term variation in RHR and the risks of incident MI and mortality among older adults.

METHODS

1991 subjects without cardiovascular disease from the Cardiovascular Health Study were included. RHR was taken from resting ECGs at the first five annual study visits. RHR mean, trend and variation were estimated with linear regression. Subjects were followed for incident MI and death until December 2010. HRs for RHR mean, trend and variation are reported for differences of 10 bpm, 2 bpm/year and 2 bpm, respectively.

RESULTS

262 subjects had an incident MI event (13%) and 1326 died (67%) during 12 years of median follow-up. In primary analyses adjusted for cardiovascular risk factors, RHR mean (HR 1.12; 95% CI 1.05 to 1.20) and variation (HR 1.08; 95% CI 1.03 to 1.13) were associated with the risk of death while trend was not. None of the RHR variables were significantly associated with the risk of incident MI events; however, CIs were wide and the MI associations with RHR variables were not significantly different from the mortality associations. Adjusting for additional variables did not affect estimates, and there were no significant interactions with sex.

CONCLUSIONS

Variation in RHR over a period of several years represents a potential predictor of long-term mortality among older persons free of cardiovascular disease.

The J-curve in arterial hypertension: fact or fallacy?

It is known that a large proportion of patients with arterial hypertension are undertreated. This may result in an increase of the incidence of cardiovascular events. On the other hand, aggressive reduction of blood pressure may increase cardiovascular events (J-curve phenomenon) in certain populations. This phenomenon may be seen in patients with coronary artery disease and left ventricular hypertrophy when the diastolic blood pressure decreases below 70-80 mm Hg, and the systolic blood pressure decreases below 130 mm Hg. This phenomenon is not seen in patients with stroke or renal disease. Thus, a safer and more conservative strategy should be applied in patients with coronary artery disease, left ventricular hypertrophy, elderly, and in patients with isolated systolic hypertension. This is depicted in the recently published European Society of Hypertension/European Society of Cardiology guidelines in which higher targets of blood pressure are suggested in certain cardiovascular diseases and in the elderly.