There is growing recognition of cardiovascular consequences of obstructive sleep apnea (OSA). Recurrent episodes of airway obstructions result in hypoxia and hypercapnia increasing sympathetic neural ...tone, which in turn causes vasoconstriction and marked increases in blood pressure (BP). BP response to OSA may be important in understanding the absence of nocturnal BP fall in the subgroup of hypertensive patients termed 'non-dippers'. Even mild sleep apnea can increase nocturnal BP through different mechanisms including hypoxemia, sympathetic activation, mechanical changes and disruption of normal sleep. Sleep apnea may be an important factor in determining the increased cardiovascular risk in hypertensive non-dippers. Effective treatment of sleep apnea may attenuate neurohumoral and metabolic abnormalities, improve diurnal BP control and conceivably reduce cardiovascular risk. This review examines the evidence linking OSA to non-dipping pattern of hypertension, and discusses potential mechanisms underlying this link. We will review first, prognostic value of nighttime BP; second, the cardiovascular consequences of sleep apnea; third, the evidence for altered diurnal BP profile in sleep apnea; fourth, the mechanisms contributing to both nocturnal and daytime hypertension in sleep apnea; fifth, the benefits of sleep apnea treatment and finally implications for hypertension management.
The aim of the study was to assess cardiac and respiratory blood pressure (BP) and subarachnoid space (SAS) width oscillations during the resting state for slow and fast breathing and breathing ...against inspiratory resistance. Experiments were performed on a group of 20 healthy volunteers (8 males and 12 females; age 25.3 ± 7.9 years; BMI = 22.1 ± 3.2 kg/m
). BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography. SAS signals were recorded using an SAS monitor. Oxyhaemoglobin saturation (SaO
) and end-tidal CO
(EtCO
) were measured using a medical monitoring system. Procedure 1 consisted of breathing spontaneously and at controlled rates of 6 breaths/minute and 6 breaths/minute with inspiratory resistance for 10 minutes. Procedure 2 consisted of breathing spontaneously and at controlled rates of 6, 12 and 18 breaths/minute for 5 minutes. Wavelet analysis with the Morlet mother wavelet was applied for delineation of BP and SAS signals cardiac and respiratory components. Slow breathing diminishes amplitude of cardiac BP and SAS oscillations. The overall increase in BP and SAS oscillations during slow breathing is driven by the respiratory component. Drop in cardiac component of BP amplitude evoked by slow-breathing may be perceived as a cardiovascular protective mechanism to avoid target organ damage. Further studies are warranted to assess long-term effects of slow breathing.
Obstructive Sleep Apnoea (OSA) constitutes the most prevalent form of abnormal respiratory control during sleep in adults. Evidence linked OSA to cardiovascular disease, and the role of OSA in ...abnormal Blood Pressure (BP) control has been extensively studied. Although longitudinal trials suggest a causative role of OSA in the development of hypertension, the evidence is not fully consistent. Nasal continuous positive airway pressure (nCPAP) applied during sleep is well documented and a highly efficient therapeutic aid to eliminate OSA. It has been repeatedly shown that nCPAP-therapy is also associated with modest BP lowering effect in hypertensive OSA-patients, and the magnitude of the observed effect correlates with the severity of OSA. However, it is unlikely that nCPAP would normalize BP.
There are few studies which tested the interplay between OSA, nCPAP and certain BPlowering drug classes. Angiotensin receptor blockers may show synergistic hypotensive effect with nCPAP, whereas mineralocorticoid receptor blocker has been shown to modestly attenuate the severity of OSA. Additionally, the application of chronotherapy may be of special use in such patients. The current evidence is sufficient to promote persistent and effective nCPAP-therapy as a standard in all eligible OSA-patients with difficult-to-control hypertension.
IntroductionNumerous studies, but not all, have suggested a positive effect of allopurinol on the cardiovascular system. The randomised, double-blind, placebo-controlled study evaluating the effect ...of allopurinol on the risk of cardiovascular events in patients with high and very high cardiovascular risk, including the presence of long-COVID-19 syndrome (ALL-VASCOR) study aims to evaluate the efficacy of allopurinol therapy for improving cardiovascular outcomes in patients at high and very high cardiovascular risk excluding ischaemic heart disease. This is particularly important due to the high cost of cardiovascular disease treatment and its status as one of the leading causes of mortality.Methods and analysisThe ALL-VASCOR study is a randomised, double-blind, placebo-controlled, multicentre trial that examines the effect of allopurinol therapy (200–500 mg of allopurinol daily) versus an equivalent dose of placebo on the risk of cardiovascular events in 1116 patients aged 40–70 with serum uric acid levels above 5 mg/dL at high and very high risk of cardiovascular disease. The ALL-VASCOR study will also assess the occurrence of long-COVID-19 syndrome. The study will measure primary and secondary as well as additional endpoints and the planned intervention will end on 31 July 2028 unless advised otherwise by the Safe Monitoring Board or other applicable authorities. Participant recruitment is planned to begin in March 2024 in Poland.Ethics and disseminationThe study was ethically approved by the Bioethics Committee of Poznan University of Medical Sciences (No 03/23, 12 January 2023). The results are expected after 2028 and will be disseminated in peer-reviewed journals and at international conferences.Protocol version number01–15 November 2022.Trial registration numberEudraCT: 2022-003573-32, 27 October 2022, ClinicalTrials: NCT05943821, 13 July 2023.
A symposium held at the 29th European Meeting on Hypertension and Cardiovascular Protection in Milan, Italy, discussed the potential impact and long-term benefits of early active management of ...cardiovascular disease (CVD) risk in patients with hypertension, and potential barriers to this strategy. Hypertension often aggregates with other cardiovascular risk factors, exponentially increasing morbidity and mortality. While effective therapies to treat hypertension exist, a substantial number of patients still experience major cardiovascular events. Two major issues account for these disappointing results: interventions initiated too late in the disease trajectory and lack of effective translation of the research findings into daily clinical practice. Results from genetic studies suggest that lifetime exposure to lower blood pressure (BP) and cholesterol levels due to protective gene mutations, can provide greater cardiovascular benefits than middle-/late-age interventions. Clinical guidelines suggest adding statins to BP-lowering therapies for further cardiovascular benefits in most hypertensive patients; however, real-world data show that physicians’ compliance with these recommendations and patients’ adherence to BP- and lipid-lowering treatments remain poor, resulting in poor risk factor control and an increased risk of adverse outcomes. The use of single-pill combinations (SPC) can partially mitigate these issues, as they are associated with increased patient adherence and improved BP control. Treatment with SPC has been recommended in the European Hypertension Guidelines, but optimization of the total CVD risk may need adoption of more ambitious treatment strategies aimed to deliver single pills that control multiple CVD risk factors. Amlodipine, perindopril and atorvastatin have been shown to improve BP and lipid levels to a great extent when given separately, and this combination has also been shown to improve cardiovascular outcomes. Overall, early intervention in patients with hypertension with use of an effective, high-intensity cardiovascular risk reduction regimen and attention to medication adherence through reducing pill burden are likely to result in optimal outcomes.
Patients with chronic kidney disease on maintenance hemodialysis (HD) have a very high risk of death in the course of COVID-19. The aim of the study was to assess the effectiveness of COVID-19 ...vaccination to reduce the incidence of COVID-19 and the fatality rate in HD patients. A retrospective registry-based cohort study was performed in all HD adult patients in the Pomeranian Voivodeship. Vaccinations were carried out from January to April 2021 with mRNA vaccines, either BNT162b2 or mRNA-1273 with two-dose schedule. In the first analysis (2nd pandemic wave), 1,160 unvaccinated patients were included (59.7% males, 25.7% diabetic). In the second analysis (4th pandemic wave), 1,131 (59.4% male, 30.7% diabetic) individuals were included, 1,042 (92.13%) were fully vaccinated. Three hundred and fifteen HD patients (27.2%) were COVID-19 positive during the 2nd wave, and 6.9% (78/1,131) during the 4th wave. Within the fully vaccinated patients of the 4th wave, 60 were COVID-19 positive, 5.8 vs. 20.2% of unvaccinated COVID-19 positive patients in 2nd wave, respectively. COVID-19 incidence rate ratio (IRR) was 0.21 (4th wave-vaccinated vs. 2nd wave-unvaccinated) indicating a 79% reduction. The IRR between vaccinated and unvaccinated patients of the 4th wave was 0.28 in favor of vaccinated patients with 72% reduction. In the 2nd wave, 93 patients died as a result of COVID-19 (fatality rate: 29.5%). The fatality rate of fully vaccinated patients during the 4th wave was 6.7% (
p
= 0.004), while the fatality rate in the 4th wave within unvaccinated patients accounted for 11.1%. Significant clinical effectiveness of COVID-19 vaccination was demonstrated in a multicenter study in HD patients.
Respiration is known to affect cerebrospinal fluid (CSF) movement. We hypothesised that increased inspiratory resistance would affect the dynamic relationship between blood pressure (BP) changes and ...subarachnoid space width (SAS) oscillations.
Experiments were performed in a group of 20 healthy volunteers undergoing controlled intermittent Mueller Manoeuvres (the key characteristic of the procedure is that a studied person is subjected to a controlled, increased inspiratory resistance which results in marked potentiation of the intrathoracic negative pressure). BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography; oxyhaemoglobin saturation with an ear-clip sensor; end-tidal CO2 with a gas analyser; cerebral blood flow velocity (CBFV), pulsatility and resistive indices with Doppler ultrasound. Changes in SAS were recorded with a new method i.e. near-infrared transillumination/backscattering sounding. Wavelet transform analysis was used to assess the BP and SAS oscillations coupling.
Initiating Mueller manoeuvres evoked cardiac SAS component decline (-17.8%, P<0.001), systolic BP, diastolic BP and HR increase (+6.3%, P<0.001; 6.7%, P<0.001 and +2.3%, P<0.05, respectively). By the end of Mueller manoeuvres, cardiac SAS component and HR did not change (+2.3% and 0.0%, respectively; both not statistically significant), but systolic and diastolic BP was elevated (+12.6% and +8.9%, respectively; both P<0.001). With reference to baseline values there was an evident decrease in wavelet coherence between BP and SAS oscillations at cardiac frequency in the first half of the Mueller manoeuvres (-32.3%, P<0.05 for left hemisphere and -46.0%, P<0.01 for right hemisphere) which was followed by subsequent normalization at end of the procedure (+3.1% for left hemisphere and +23.1% for right hemisphere; both not statistically significant).
Increased inspiratory resistance is associated with swings in the cardiac contribution to the dynamic relationship between BP and SAS oscillations. Impaired cardiac performance reported in Mueller manoeuvres may influence the pattern of cerebrospinal fluid pulsatility.
Vascular aging is a physiological, multifactorial process that involves every type of vessel, from large arteries to microcirculation. This manifests itself as impaired vasomotor function, altered ...secretory phenotype, deteriorated intercellular transport function, structural remodeling, and aggravated barrier function between the blood and the vascular smooth muscle layer. Iron disorders, particularly iron overload, may lead to oxidative stress and, among other effects, vascular aging. The elevated transferrin saturation and serum iron levels observed in iron overload lead to the formation of a non-transferrin-bound iron (NTBI) fraction with high pro-oxidant activity. NTBI can induce the production of reactive oxygen species (ROS), which induce lipid peroxidation and mediate iron-related damage as the elements of oxidative stress in many tissues, including heart and vessels' mitochondria. However, the available data make it difficult to precisely determine the impact of iron metabolism disorders on vascular aging; therefore, the relationship requires further investigation. Our study aims to present the current state of knowledge on vascular aging in patients with deteriorated iron metabolism.
Much recent attention has been given to the carotid body because of its potential role in cardiovascular disease states. One disease, neurogenic hypertension, characterised by excessive sympathetic ...activity, appears dependent on carotid body activity that may or may not be accompanied by sleep-disordered breathing. Herein, we review recent literature suggesting that the carotid body acquires tonicity in hypertension. We predict that carotid glomectomy will be a powerful way to temper excessive sympathetic discharge in diseases such as hypertension. We propose a model to explain that signalling from the ‘
hypertensive’
carotid body is tonic, and hypothesise that there will be a sub-population of glomus cells that channel separately into reflex pathways controlling sympathetic motor outflows.
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