Pulse pressure amplification, adiposity and metabolic syndrome in subjects under chronic antihypertensive therapy: The role of heart rate

Prediction of cardiovascular events by central blood pressure using radial tonometry in type 2 diabetes mellitus patients

Background

High blood pressure (BP) and type 2 diabetes mellitus (T2DM) are major causes of atherosclerotic cardiovascular disease (ASCVD) and heart failure (HF). Central blood pressure (CBP) is more predictive of ASCVD than is brachial BP; however, an association of CBP with ASCVD has not been found in T2DM patients. We evaluated the impact of CBP and the association between optimal level of noninvasively measured CBP and office BP in T2DM patients based on composite outcome of ASCVD, HF, and complications of hypertension.

Methods

Patients were enrolled from June 2011 to December 2015 and were followed up through December 2019. CBP was measured using radial tonometry. The primary endpoints were composite outcome of ASCVD, HF, and hypertension-induced complications such as left ventricular hypertrophy, retinopathy, and proteinuria.

Results

During the 6.5-year follow-up period, 515 patients were enrolled in the study. A total of 92 patients (17.9%) developed primary endpoints. The mean age of subjects was 61.3 ± 12.1 years and 55% (n = 283) were male. Patients who developed primary endpoints were older (65.3 ± 9.5 years vs. 60.5 ± 12.4 years) and had lower high-density lipoprotein (36.6 ± 9.4 mg/dL vs. 41.8 ± 11.1 mg/dL), higher CBP (123.6 ± 20.6 mmHg vs. 118.0 ± 20.6 mmHg), and higher pulse pressure (61.3 ± 16.6 mmHg vs. 56.5 ± 15.1 mmHg) than subjects without primary endpoint development. After adjustment for various risk factors, CBP was an independent predictor for primary endpoints (hazard ratio, 1.14; 95% confidence interval, 1.02–1.27; P = 0.016). In addition, the association of CBP and primary endpoints showed a U-shaped curve with the lowest incidence at CBP 118 mmHg and systolic BP about 128 mmHg.

Conclusions

We show the importance of CBP measurements in T2DM patients and present a cutoff value for ASCVD events and hypertension-induced complications.

Radial vs coccygeal artery Doppler blood pressure measurement in conscious cats

Objectives The aims of the study were to compare the results of systolic blood pressure (SBP) measurements at the radial and coccygeal artery by Doppler ultrasonography and to assess the impact of gender, age, body weight, body condition score (BCS) and stress score on disagreements. Methods Eighty cats were included in this prospective, block randomised crossover trial. Blood pressure measurements were performed at home, during hospitalisation or in a local animal shelter by a single trained observer according to the latest ISFM consensus guidelines. Statistical analysis included Spearman's correlation and ANOVA. Results Measurement or site order had no effect on blood pressure measurements ( P = 0.157, P = 0.965). Correlation of radial and coccygeal SBP was moderate (rsp = 0.519, P <0.001) and measurements at the tail were by mean 18.7 ± 37 mmHg higher. The differences between the measuring sites were neither correlated with age (rsp = 0.044, P = 0.710) nor with body weight (rsp = 0.122, P = 0.337). A significant effect of BCS ( P = 0.016), but not gender ( P = 0.246) or stress score ( P = 0.424) was identified. Of the 25 cats with a coccygeal SBP ⩾170 mmHg, 14 (56%) were categorised as mildly hypertensive or normotensive when measurements were performed at the forelimb. Conclusions and relevance Choice of the measuring site, coccygeal vs radial artery, has a significant impact on Doppler ultrasonographic SBP results. In many cats, these discrepancies are huge and would certainly affect treatment decisions. Possible explanations include cone-shaped tails, especially in obese cats, leading to distal gapping or slippage of cylindrical cuffs and peripheral pulse pressure amplification. Further studies are urgently needed to clarify whether the discordances are artefacts or have a pathological background.

Heart rate is associated with increased risk of major cardiovascular events, cardiovascular and all-cause death in patients with stable chronic cardiovascular disease: an analysis of ONTARGET/TRANSCEND

AIMS

Heart rate was proposed as an emergent cardiovascular (CV) risk factor. Previous studies have shown associations between increased heart rate and CV risk in various populations. We aimed to evaluate the prognostic relevance of heart rate in a large contemporaneous medically optimized cohort of patients with stable chronic CV disease.

METHODS AND RESULTS

In a post hoc analysis of the ONTARGET/TRANSCEND trials, we evaluated associations between baseline and average heart rate in trial with CV risk in 31, 531 patients followed for a median of 5 years. The primary outcome, major vascular events (MVE), was a composite of CV death, myocardial infarction (MI), stroke, and congestive heart failure (CHF). Pre-specified secondary outcomes included all-cause death and the individual components of the primary outcome. Associations between heart rate and outcomes were computed with heart rate as a continuous variable, baseline heart rate >70 vs ≤ 70 bpm, and across heart rate quintiles, adjusting for other markers of risk, beta-blocker and non-dihydropyridine calcium channel blocker use. For each 10 bpm increase in baseline and average heart rate, we observed a significant increase in risk of MVE, CV death, CHF and all-cause death. There was a continuous relationship between MVE and baseline and, more importantly, average in-trial heart rate, with no observed threshold. MVE, CV death, stroke, CHF, and all-cause death increased across heart rate quintiles. There was no association between MI and HR. Results were consistent in clinically relevant subgroups. There were modest but significant improvements in C-statistic and in statistical measures of model calibration for models that included heart rate for MVE, CV death, CHF and all-cause death.

CONCLUSIONS

This large study examined and quantitated associations between heart rate and CV events in a contemporary medically optimized population with stable CV disease. Resting and, in particular, in-trial average heart rate are independently associated with significant increases in CV events and all-cause death.

Pulse pressure amplification in relation to body fatness

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Aortic-brachial pulse pressure amplification (PPA) is a measure of arterial elasticity and it is also an independent cardiovascular risk factor. The PPA is mainly determined by age, height, central and peripheral pressure waveforms characteristics, including measures of arterial stiffness and wave reflection.

WHAT THIS STUDY ADDS

In this study, however, we demonstrate that PPA is also significantly associated with indirect indices of body fatness. As the body fatness is treatable, our findings might be used as a reference for future studies on the effects of body fat reduction on PPA and the PPA-related cardiovascular risk. AIMS Arterial pressure transfer to the periphery is accompanied by pulse pressure amplification (PPA). Pulse pressure is influence by body fat. The purpose of the present study was to evaluate any possible inter-relation between body fatness and PPA in healthy subjects.

METHODS

Haemodynamic and wave reflection indices were estimated by pulse wave analysis. Body fat was measured by bio-impedance.

RESULTS

A total of 367 healthy volunteers (136 men and 231 women) was studied. Pulse pressure amplification correlated significantly with percentage of body fat (r=-0.53, P < 0.0001), age (r=-0.62, P < 0.0001), height (r= 0.43, P < 0.0001), heart rate (r= 0.28, P < 0.0001) and mean blood pressure (r=-0.29, P < 0.0001). The association of PPA with body fat was also significant in a multiple linear regression model. Age was an independent predictor of PPA and analysis of study subjects subdivided into two groups, those <50 years and those >50 years showed that body fatness correlated inversely and significantly with PPA in individuals both younger and older than 50 years (r=-0.44, P < 0.0001, r=-0.37, P < 0.0001 respectively). Augmentation pressure was also associated significantly with percentage of body fat in both subgroups (r= 0.48, P < 0.0001 and r= 0.49, P < 0.0001 respectively).

CONCLUSIONS

This study performed on healthy subjects showed that pulse pressure amplification is related to body fatness over a wide age range. Percentage body fat is significantly associated with augmentation pressure, a component of central pulse pressure.

Association between metabolic syndrome and parameters of 24-hour blood pressure ambulatory monitoring

OBJECTIVE: To investigate associations between metabolic syndrome (MS) and 24-hour blood pressure parameters as a measure of cardiovascular risk (CVR). SUBJECTS AND METHODS: 136 hypertensive subjects, of both sexes, aged between 29 and 83 years were studied. CVR was defined as having at least three of the following conditions: 1) systolic/diastolic blood pressure (BP) ≥ 140/90 mmHg, absence/atennuation of nighttime fall in BP during sleep, pulse pressure (PP) ≥ 53 mmHg; 2) 24-h PP > 53 mmHg, 3) nighttime PP > 53 mmHg, 4) daytime PP > 53 mmHg and 5) nighttime fall in BP during sleep. RESULTS: The 24-h PP, daytime PP and nighttime PP were elevated in 54% of the population. Hypertriglyceridemia (52%), low HDL (72.8%), abdominal obesity (60.3%), MS (58.1%), dyslipidemia (88.8%), overweight (74.3%) and obesity (33.8%) were also elevated. Age-adjusted MS was associated with higher CVR (OR = 4.5 and 3.6), 24-h PP (OR = 2.3 and 4.7), and daytime PP (OR = 2.2 and 4.6). CONCLUSIONS: MS was highly prevalent and correlated with altered 24-hour blood pressure parameters.

Macrovascular and microvascular dysfunction in the metabolic syndrome

The metabolic syndrome (MetS) is associated with increased risk of type-2 diabetes and cardiovascular disease (CVD). We hypothesized that both small and large arteries may be impaired in subjects with the MetS, even in the absence of known CVD or diabetes. We compared both skin capillary density (CD) and pulse-wave velocity (PWV) in 36 cases with the MetS with those from 108 age- and gender-matched controls from the SU.VIM.AX-2 cohort. Compared with controls, MetS subjects demonstrated increased PWV (12.2+/-2.8 vs. 10.7+/-1.9 m s(-1), P=0.005) and lower functional CD (83.1+/-15.7 vs. 89.4+/-14.2 capillaries per mm(2), P=0.03). Functional CD was inversely related to fasting glucose, triglycerides (TGs) and HOMA-IR (all P<0.05). On the other hand, no association was found between CD and BP or with PWV. In multivariate models, the odds ratios (95% confidence interval) for one standard deviation change, for having an impaired PWV (>or=12 m s(-1), n=44), were: 1.65 (1.11-2.45) for systolic BP and 1.93 (1.25-2.99) for TG only. For impaired CD (<or=80 capillaries per mm(2)), the odds ratios (95% confidence interval) were 1.45 (1.00-2.08) for TG and 1.65 (1.13-2.43) for fasting glucose, only. In conclusion, MetS subjects exhibited evidence of macro- and microcirculatory dysfunction, even in the absence of diabetes and CVD. The common mechanism linking MetS components to CVD risk through small- and large-artery dysfunctions may be mediated through metabolic factors related to insulin resistance, not to increased BP.

Heart rate in coronary syndromes and heart failure

In the past 2 decades, there have been growing evidences that resting heart rate might be a marker of risk or even a risk factor for cardiovascular morbidity and mortality. This article reviews current evidences concerning the relation between heart rate and patients' outcome in different clinical settings such as acute coronary syndromes, left ventricular systolic dysfunction, and heart failure. The relationship between resting heart rate and the development of coronary artery disease, as well as all-cause and cardiovascular mortality, has been found to be strong, graded, and independent from other risk factors. Several lines of research indicate that heart rate plays an important role in the pathophysiology of atherosclerosis and in the clinical manifestations of coronary artery disease and that it is an independent prognostic factor in all coronary syndromes. The prognostic value of elevated heart rate in patients with heart failure has been tested in several clinical trials evaluating pharmacologic heart rate-lowering agents (eg, beta-blockers). It is difficult to determine which percentage of the clinical benefit obtained with beta-blockers is related to induced bradycardia because cardiac slowing is only one of the effects of these drugs. In the BEAUTIFUL trial, a subgroup analysis conducted in patients with resting HR more than 70 beats per minute showed that treatment with ivabradine was able to improve outcome. According to the results presented in this review, we can conclude that heart rate is a predictor of death in both stable coronary artery disease and acute coronary syndromes. Elevated heart rate is also able to negatively predict clinical outcomes in patients with heart failure. However, it is still unclear if heart rate reduction per se can improve prognosis.

The metabolic syndrome and its traits as risk factors for subclinical atherosclerosis

CONTEXT AND OBJECTIVE

The metabolic syndrome (MetS) indicates an increased cardiovascular risk. The objective of the present study was to determine the impact of the MetS and its individual traits on subclinical atherosclerosis, as measured with six noninvasive measurements of atherosclerosis (NIMA) in a 50- to 70-yr-old Dutch population-based cohort. Furthermore, we determined the impact of three different definitions of the MetS.

DESIGN

We performed NIMA in 1517 participants of the Nijmegen Biomedical Study. The MetS was defined by definitions of the National Cholesterol Education Program, International Diabetes Federation, and the World Health Organization.

RESULTS

Participants with the MetS (National Cholesterol Education Program) were characterized by increased subclinical atherosclerosis compared with participants without any trait of the MetS, as reflected by lower ankle-brachial index at rest [percent change (95% confidence interval), M: -5.2% (-9; -1), F: -3.1% (-6; -1)] and after exercise [M: -7.7% (-17;+2), F: -6.6% (-11; -2)], higher augmentation index [M: +4.8% (+3; +7), F: +1.9% (+4; +18)], increased pulse wave velocity [M: +22.8% (+15;+32), F: +20.5% (+14; +28)], increased intima-media thickness [M: +9.3% (+5; +13), F: +6.9% (+3; +11)], and thicker plaques [M: +17.6% (-2; +41), F: +26.6% (+5; +53)]. Most intriguingly, the number of traits was strongly associated with the severity of subclinical atherosclerosis because all NIMA gradually deteriorated with increasing number of traits present; NIMA were already deteriorated when one or two traits were present and further deteriorated when four or five traits of the MetS were present. Similar result were found when International Diabetes Federation and World Health Organization definitions of the MetS were used.

CONCLUSIONS

For cardiovascular risk prediction, it is more important to take into account the presence of each individual trait and the number of traits of the MetS than to diagnose the presence of the MetS.

Impact of age on the independent association of adiposity with pulse-wave velocity in a population sample of African ancestry

BACKGROUND

We aimed to clarify whether age influences the independent relationship between adiposity and pulse-wave velocity (PWV).

METHODS

We explored the effect of age on the independent relationships between indexes of central adiposity (waist circumference (WC) and waist-to-hip ratio (WHR)) and carotid-femoral PWV, central augmentation index (AIc), or pressure wave amplification assessed from applanation tonometry measurements obtained at the radial, carotid, and femoral arteries in 508 randomly selected subjects >16 years of age in a population sample of African ancestry with a high prevalence of excess adiposity ( approximately 63% overweight or obese).

RESULTS

In women a strong interaction between age and either WC or WHR was associated with logPWV independent of confounders and the individual terms (r = 0.68, P < 0.0001). This translated into a markedly greater increase in logPWV with increases in either WC or WHR in women older than the median age as compared to women younger (slopes of WC-logPWV relationships = 0.0031 +/- 0.0009 vs. -0.0007 +/- 0.0007, P < 0.002). In women older than the median age for the group, a one s.d. increase in WC (12.8 cm) translated into a 0.70 m/s increase in PWV as compared to a 0.14 m/s decrease in PWV for each one s.d. increase in WC (13.0 cm) in women younger than the median age (P < 0.001). No index of adiposity was independently associated with the log of AIc or aortic-brachial wave amplification.

CONCLUSION

In women of African ancestry, a greater independent effect of adiposity on PWV is noted in older as compared to younger women.