Heritability of resting heart rate and association with mortality in middle-aged and elderly twins

Importance of resting heart rate

Resting heart rate is a determinant of cardiac output and physiological homeostasis. Although a simple, but critical, parameter, this vital sign predicts adverse outcomes, including mortality, and development of diseases in otherwise normal and healthy individuals. Temporal changes in heart rate can have valuable predictive capabilities. Heart rate can reflect disease severity in patients with various medical conditions. While heart rate represents a compilation of physiological inputs, including sympathetic and parasympathetic tone, aside from the underlying intrinsic sinus rate, how resting heart rate affects outcomes is uncertain. Mechanisms relating resting heart rate to outcomes may be disease-dependent but why resting heart rate in otherwise healthy, normal individuals affects outcomes remains obscure. For specific conditions, physiologically appropriate heart rate reductions may improve outcomes. However, to date, in the normal population, evidence that interventions aimed at reducing heart rate improves outcomes remains undefined. Emerging data suggest that reduction in heart rate via vagal activation and/or sympathetic inhibition is propitious.

Genetic insights into resting heart rate and its role in cardiovascular disease

Resting heart rate is associated with cardiovascular diseases and mortality in observational and Mendelian randomization studies. The aims of this study are to extend the number of resting heart rate associated genetic variants and to obtain further insights in resting heart rate biology and its clinical consequences. A genome-wide meta-analysis of 100 studies in up to 835,465 individuals reveals 493 independent genetic variants in 352 loci, including 68 genetic variants outside previously identified resting heart rate associated loci. We prioritize 670 genes and in silico annotations point to their enrichment in cardiomyocytes and provide insights in their ECG signature. Two-sample Mendelian randomization analyses indicate that higher genetically predicted resting heart rate increases risk of dilated cardiomyopathy, but decreases risk of developing atrial fibrillation, ischemic stroke, and cardio-embolic stroke. We do not find evidence for a linear or non-linear genetic association between resting heart rate and all-cause mortality in contrast to our previous Mendelian randomization study. Systematic alteration of key differences between the current and previous Mendelian randomization study indicates that the most likely cause of the discrepancy between these studies arises from false positive findings in previous one-sample MR analyses caused by weak-instrument bias at lower P-value thresholds. The results extend our understanding of resting heart rate biology and give additional insights in its role in cardiovascular disease development.

Admission Heart Rate and Mortality in Critically Ill Patients with Acute Aortic Dissection

The association between admission heart rate (HR) and the mortality of critically ill patients with acute aortic dissection (AAD) remains unclear.The data were extracted from the Medical Information Mart for Intensive Care (MIMIC-III) database. Cox regression models and Kaplan-Meier (KM) survival curve were used to explore the association between admission HR and 90-day, 1-year, and 3-year mortality in patients with AAD. Sensitivity analyses were conducted to assess potential bias.A total of 374 eligible AAD patients were included and divided in 4 groups according to admission HR (HR ≤ 70, 71-80, 81-90, and > 90 beats per minute (bpm) ). The patients with AAD in the group with HR > 90 bpm had higher 90-day, 1-year, and 3-year mortality than those in the groups with HR ≤ 70, 71-80, and 81-90 bpm. After adjusting for age, sex, BMI, systolic blood pressure, diastolic blood pressure, SOFA score, SAPSII score, Stanford type, hypertension, coronary artery disease, liver disease, atrial fibrillation, valvular disease, intensive care unit mechanical ventilation, aortic surgery, and thoracic endovascular aortic repair, patients with admission HR > 90 bpm had a higher risk of 90-day, 1-year, and 3-year mortality [adjusted hazard ratio, 95% confidence interval, 5.14 (2.22-11.91) P < 0.001; 4.31 (2.10-8.84) P < 0.001; 3.01 (1.66-5.46) P < 0.001] than those with HR 81-90 bpm. The 90-day, 1-year, and 3-year mortality were similar among the groups with HR ≤ 70, 71-80, and 81-90 bpm.Admission HR > 90 bpm was independently associated with all-cause mortality in critically ill AAD patients, either type A or B aortic dissection.

Sympathetic nervous system and hypertension: New evidences

Evidences collected in the past few years have strengthened the concept that the sympathetic nervous system plays a primary role in the development and progression of the hypertensive state, starting from the early stage, and in the hypertension-related cardiovascular diseases. Several pathophysiological mechanisms are involved. Among them the genetic background, the immune system in conjunction with sympathetic activation. The present review will briefly discuss the importance of the above mentioned mechanisms in the development of hypertension. The paper will also examine the sympathetic mechanisms underlying attended vs unattended blood pressure measurements as well as their role in resistant vs pseudo-resistant hypertension. Finally evidence from recent meta-analysis on the relevance of sympathetic nerve traffic activation in the pathogenesis of hypertension will be briefly discussed.

Translational and interdisciplinary insights into presbyacusis: A multidimensional disease

There are multiple etiologies and phenotypes of age-related hearing loss or presbyacusis. In this review we summarize findings from animal and human studies of presbyacusis, including those that provide the theoretical framework for distinct metabolic, sensory, and neural presbyacusis phenotypes. A key finding in quiet-aged animals is a decline in the endocochlear potential (EP) that results in elevated pure-tone thresholds across frequencies with greater losses at higher frequencies. In contrast, sensory presbyacusis appears to derive, in part, from acute and cumulative effects on hair cells of a lifetime of environmental exposures (e.g., noise), which often result in pronounced high frequency hearing loss. These patterns of hearing loss in animals are recognizable in the human audiogram and can be classified into metabolic and sensory presbyacusis phenotypes, as well as a mixed metabolic+sensory phenotype. However, the audiogram does not fully characterize age-related changes in auditory function. Along with the effects of peripheral auditory system declines on the auditory nerve, primary degeneration in the spiral ganglion also appears to contribute to central auditory system aging. These inner ear alterations often correlate with structural and functional changes throughout the central nervous system and may explain suprathreshold speech communication difficulties in older adults with hearing loss. Throughout this review we highlight potential methods and research directions, with the goal of advancing our understanding, prevention, diagnosis, and treatment of presbyacusis.

Diagnosis and management of an inappropriate sinus tachycardia in adolescence based upon a Holter ECG: A retrospective analysis of 479 patients

Inappropriate sinus tachycardia (IST) is a common disease of the autonomic nervous system in children and adults. Diagnosis and treatment of IST in adolescents is not well defined. In this retrospective study, we tested our hypothesis regarding autonomic dysfunction in childhood by analyzing 24-h heart rate variability (HRV) in 479 children, with a mean age of 13.7 ± 2.1 years, who were referred to the outpatient clinic in the Pediatrics Department within the last 15 years. Seventy-four adolescents with a mean 24-h heart rate ≥ 95 bpm (our cut-off for an IST based upon 66 healthy controls) were deemed to have IST. We found the risk of IST to be high in adolescents with attention deficit disorder (OR = 3.5,p<0.001), pre-hypertension (OR = 2.5, p = 0.043) and hypertension (OR = 2.1,p = 0.02); insignificantly enhanced in children with short stature (OR = 1.9,p = 0.19), surgically-treated congenital heart disease (OR = 1.4,p = 0.51) and obesity without hypertension (OR = 1.4;p = 0.25); and negligible in adolescents with anorexia nervosa (OR = 0.3, p = 0.26) and constitutional thinness (OR = 0.9,p = 0.89). IST was associated with a significant decrease in global HRV and elevated blood pressures, indicating an enhanced cardiovascular risk. Methylphenidate did not increase 24-h heart rates, whereas omega-3 fatty acid supplementation significantly decreased elevated heart rates and increased HRV in adolescents with IST. In this retrospective analysis, 15.4% of adolescents suffered from IST with a 24-h heart rate ≥ 95 bpm, predominately due to attention deficit disorder and hypertension.

Heart rate as a predictor of cardiovascular risk

Heart rate is a parameter that is very easy to measure and is widely used both in clinic and during daily life activities. Its value gained more relevance with the evidence, in prospective studies and meta-analysis, of association between elevated heart rate values and diseases and outcomes.The increased knowledge of physiological mechanisms of heart rate control and the pathophysiological mechanisms responsible for its dysfunction allows to identify the cut-off value of normalcy providing info for non-pharmacological and pharmacological treatments to reduce the cardiovascular risk both in general population and in pathophysiological conditions. This paper overviews the knowledges of the role of resting heart rate as predictor of cardiovascular risk.

Identification of Frailty and Its Risk Factors in Elderly Hospitalized Patients from Different Wards: A Cross-Sectional Study in China

OBJECTIVES

To survey the difference of frailty prevalence in elderly inpatients amongdifferent wards; to compare the diagnostic performance of five frailty measurements (Clinical Frailty Scale [CFS], FRAIL, Fried, Edmonton, Frailty Index [FI]) in identifying frailty; and to explore the risk factors of frailty in elderly inpatients.

PARTICIPANTS AND METHODS

This was a cross-sectional study including 1000 inpatients (mean age 75.2±6.7 years, 51.5% male; 542, 229, and 229 patients from cardiology, non-surgical, and surgical wards, respectively) in a tertiary hospital from September 2018 to February 2019. We applied the combined index to integrate the five frailty measurements mentioned above as the gold standard of frailty diagnosis. Multivariate logistic regression models were used to determine the independent risk factors of frailty.

RESULTS

Frailty prevalence was 32.3% (Fried), 36.2% (CFS), 19.2% (FRAIL), 25.2% (Edmonton), 35.1% (FI) in all patients. The frailty was more common in non-surgical wards, regardless of the frailty assessment tools used (non-surgical wards: 27.5% to 51.5%; cardiology ward: 14.9% to 29.3%; surgical wards: 18.8% to 41.9%). CFS≥5 showed a sensitivity of 94.1% and a specificity of 85.2% for all patients. FI≥0.25 showed a sensitivity of 94.8% and a specificity of 87.0% for all patients. Age [odds ratio (OR) = 1.089, P<0.001], education level (OR = 0.782, P=0.001), heart rate (OR = 1.025, P<0.001), albumin (OR = 0.911, P=0.002), log D-dimer (OR = 2.940, P<0.001), ≥5 comorbidities (OR = 2.164, P=0.002), and ≥5 medications (OR = 2.819, P<0.001) were independently associated with frailty in all participants.

CONCLUSION

Frailty is common among elderly inpatients, especially in non-surgical wards. CFS is a preferred screening tool and FI may be an optimal assessment tool. Old age, low educational level, fast heart rate, low albumin, high D-dimer, ≥5 comorbidities, and polypharmacy are independent risk factors of frailty in elderly hospitalized patients.

Genetic and environmental factors on heart rate, mean arterial pressure and carotid intima-media thickness: A longitudinal twin study

BACKGROUND

Heart rate (HR), mean arterial pressure (MAP) and carotid intima-media thickness (cIMT) are moderately heritable cardiovascular traits, but the environmental effects on the longitudinal change of their heritability have never been investigated.

METHODS

368 Italian and Hungarian twins (107 monozygotic, 77 dizygotic) underwent oscillometric measurement and B-mode sonography of bilateral carotid arteries in 2009/2010 and 2014. Within- -individual/cross-study wave, cross-twin/within-study wave and cross-twin/cross-study wave correlations were estimated, and bivariate Cholesky models were fitted to decompose the total variance at each wave and covariance between study waves into additive genetic, shared and unique environmental components.

RESULTS

For each trait, a moderate longitudinal stability was observed, with within-individual/crosswave correlations of 0.42 (95% CI: 0.33-0.51) for HR, 0.34 (95% CI: 0.24-0.43) for MAP, and 0.23 (95% CI: 0.12-0.33) for cIMT. Cross-twin/cross-wave correlations in monozygotic pairs were all significant and substantially higher than the corresponding dizygotic correlations. Genetic continuity was the main source of longitudinal stability, with across-time genetic correlations of 0.52 (95% CI: 0.29-0.71) for HR, 0.56 (95% CI: 0.31-0.81) for MAP, and 0.36 (95% CI: 0.07-0.64) for cIMT. Overlapping genetic factors explained respectively 57%, 77%, and 68% of the longitudinal covariance of the HR, MAP and cIMT traits.

CONCLUSIONS

Genetic factors have a substantial role in the longitudinal change of HR, MAP and cIMT; however, the influence of unique environmental factors remains relevant. Further studies should better elucidate whether epigenetic mechanisms have a role in influencing the stability of the investigated traits over time.

Genetics of heart rate in heart failure patients (GenHRate)

BACKGROUND

Elevated resting heart rate (HR) is a risk factor and therapeutic target in patients with heart failure (HF) and reduced ejection fraction (HFrEF). Previous studies indicate a genetic contribution to HR in population samples but there is little data in patients with HFrEF.

METHODS

Patients who met Framingham criteria for HF and had an ejection fraction < 50% were prospectively enrolled in a genetic HF registry (2007-2015, n = 1060). All participants donated blood for DNA and underwent genome-wide genotyping with additional variants called via imputation. We performed testing of previously identified variant "hits" (43 loci) as well as a genome-wide association (GWAS) of HR, adjusted for race, using Efficient Mixed-Model Association Expedited (EMMAX).

RESULTS

The cohort was 35% female, 51% African American, and averaged 68 years of age. There was a 2 beats per minute (bpm) difference in HR by race, AA being slightly higher. Among 43 candidate variants, 4 single nucleotide polymorphisms (SNPs) in one gene (GJA1) were significantly associated with HR. In genome-wide testing, one statistically significant association peak was identified on chromosome 22q13, with strongest SNP rs535263906 (p = 3.3 × 10^-8). The peak is located within the gene Cadherin EGF LAG Seven-Pass G-Type Receptor 1 (CELSR1), encoding a cadherin super-family cell surface protein identified in GWAS of other phenotypes (e.g., stroke). The highest associated SNP was specific to the African American population.

CONCLUSIONS

These data confirm GJA1 association with HR in the setting of HFrEF and identify novel candidate genes for HR in HFrEF patients, particularly CELSR1. These associations should be tested in additional cohorts.

Leisure time and occupational physical activity, resting heart rate and mortality in the Arctic region of Norway: The Finnmark Study

Aims

This study examined the association of leisure time physical activity, occupational physical activity, and resting heart rate with all-cause and cardiovascular disease mortality in Sami and non-Sami populations.

Study design

This was a longitudinal, observational population-based study.

Methods

The Finnmark 3 study cohort was examined in 1987–1988 and followed for all-cause and cardiovascular disease mortality for 26 years. The cohort included 17,697 men and women with a mean age of 47.2 years at baseline. Leisure time physical activity and occupational physical activity were assessed with a validated questionnaire at baseline, whereas cause of death was obtained from the Norwegian Cause of Death Registry.

Results

A total of 1983 women and 3147 men died during follow-up. Leisure time physical activity was linearly and inversely associated with all-cause mortality, but not coronary heart disease mortality. Compared to inactive subjects, all-cause mortality was significantly reduced by 16% in the active leisure time physical activity group (hazard ratio 0.84; 95% confidence interval 0.76–0.92). Both for all-cause and cardiovascular disease mortality, we observed a U-shaped relationship with occupational physical activity, as participants in the walking and lifting group had significantly lower mortality than both the mostly sedentary and the heavy manual labour group ( p < 0.05). An increase in resting heart rate by one beat per minute was associated with a 1.1% increase in all-cause mortality (hazard ratio 1.011; 95% confidence interval 1.009–1.013). The associations were similar in Sami and non-Sami subjects.

Conclusion

In this population-based study, leisure time physical activity was inversely associated with all-cause mortality, whereas resting heart rate was positively associated with all-cause and cardiovascular disease mortality. There was a U-shaped association between occupational physical activity and cardiovascular disease and all-cause mortality.

Living alone is associated with all-cause and cardiovascular mortality: 32 years of follow-up in the Copenhagen Male Study

Aims

As a consequence of modern urban life, an increasing number of individuals are living alone. Living alone may have potential adverse health implications. The long-term relationship between living alone and all-cause and cardiovascular mortality, however, remains unclear.

Methods and results

Participants from The Copenhagen Male Study were included in 1985–86 and information about conventional behavioural, psychosocial, and environmental risk factors were collected. Socioeconomic position (SEP) was categorized into four groups. Multivariable Cox-regression models were performed with follow-up through the Danish National Registries. A total of 3346 men were included, mean (standard deviation) age 62.9 (5.2) years. During 32.2 years of follow-up, 89.4% of the population died and 38.9% of cardiovascular causes. Living alone (9.6%) was a significant predictor of mortality. Multivariable risk estimates were [hazard ratio (95% confidence interval)] 1.23 (1.09–1.39), P = 0.001 for all-cause mortality and 1.36 (1.13–1.63), P = 0.001 for cardiovascular mortality. Mortality risk was modified by SEP. Thus, there was no association in the highest SEP but for all other SEP categories, e.g. highest SEP for all-cause mortality 1.01 (0.7–1.39), P = 0.91 and 0.94 (0.6–1.56), P = 0.80 for cardiovascular mortality; lowest SEP 1.58 (1.16–2.19), P = 0.004 for all-cause mortality and 1.87 (1.20–2.90), P = 0.005 for cardiovascular mortality. Excluding participants dying within 5 years of inclusion (n = 274) did not change estimates, suggesting a minimal influence of reverse causation.

Conclusions

Living alone was an independent risk factor for all-cause and cardiovascular mortality with more than three decades of follow-up. Individuals in middle- and lower SEPs were at particular risk. Health policy initiatives should target these high-risk individuals.

How Heart Rate Should Be Controlled in Patients with Atherosclerosis and Heart Failure

PURPOSE OF REVIEW

Resting heart rate is an independent risk factor for all-cause and cardiovascular mortality in patients with heart failure. The main objectives are to discuss the prognosis of heart rate, its association with coronary atherosclerosis, and the modalities of control of the heart rate in sinus rhythm and in the rhythm of atrial fibrillation in patients with chronic heart failure.

RECENT FINDINGS

As a therapeutic option for control heart rate, medications such as beta-blockers, digoxin, and finally ivabradine have been studied. Non-dihydropyridine calcium channel blockers are contraindicated in patients with heart failure and reduced ejection fraction. The influence of the magnitude of heart rate reduction and beta-blocker dose on morbidity and mortality will be discussed. Regarding the patients with heart failure and atrial fibrillation, there are different findings in heart rate control with the use of a beta-blocker. Patients eligible for ivabradine have clinical benefits and increased ejection fraction. Vagal nerve stimulation has low efficacy for the control of heart rate. Complementary therapies such as tai chi and yoga showed no effect on heart rate. In this review, we discuss the main therapeutic options for the control of heart rate in patients with atherosclerosis and heart failure. More research is needed to examine the effects of therapeutic options for heart rate control in different population types, as well as their effects on clinical outcomes and impact on morbidity and mortality.

Heart rate as a predictor of cardiovascular risk

BACKGROUND

Heart rate (HR) is a predictor of cardiovascular, cerebrovascular and all-cause mortality in the general population, as well as in patients with cardio- and cerebrovascular diseases. We aimed to summarize current knowledge regarding the influence of HR on cardio- and cerebrovascular morbidity and mortality.

MATERIALS AND METHODS

PubMed, MEDLINE, Ovid and EMBASE databases were searched for large follow-up studies or meta-analysis published between January 1990 and September 2017 in the English language using the following keyword "heart rate," "resting heart rate," "mortality," "outcome," "hypertension," "heart failure," "ischaemic heart disease," "coronary heart disease" and "stroke."

RESULTS

The relationship between increased HR and cardio- and cerebrovascular morbidity and mortality has been reported in a large number of studies, and the results regarding this association are concurrent. This connection is generally stronger in men than in women. The increase in HR usually occurs in parallel with elevation of blood pressure and metabolic disturbances (insulin resistance, dyslipidaemia). However, even after adjustment for the most important cardiovascular risk factors, HR remained an independent predictor of adverse events in global population or in patients with cardio- and cerebrovascular diseases.

CONCLUSION

HR has an important negative effect on cardio- and cerebrovascular morbidity and mortality. Future longitudinal investigations should clarify HR significance and optimal HR reduction for primary and secondary prevention in cardio- and cerebrovascular events.

Sex- and Age-Related Reference Values in Cardiology, with Annotations and Guidelines for Interpretation

The definition of "abnormal" in clinical sciences is often based on so-called reference values which point to a range that experts by some sort of consensus consider as normal when looking at biological variables. Such a level is commonly calculated by taking (twice) the standard deviation from the mean, or considering certain percentiles. The suspicion or even confirmation of a disease is then established by demonstrating that the value measured exceeds the upper or lower reference value. As is often the case, the measurement accuracy may depend on the conditions and specific method employed to collect and analyze data. This implies that, for example, data assessed by 2D echocardiography possibly differ from those obtained by MRI and therefore require modality-specific reference values. In this review we summarize reference values for the electrocardiogram, cardiac compartmental volumes, and arterial vessel size in males and females for various age groups. These values may further depend on other variables such as body size, physical training status, and ethnicity. Additional variables relevant for cardiology such as those referring to the microcirculation and biomarkers are only mentioned with reference to the pertinent literature. In general, the sex- and age-specific differences observed are often remarkable and warrant consideration in clinical practice and basic biomedical sciences.