The prevalence, incidence, prognosis, and associated conditions of resistant hypertension. Semin Nephrol. 2014;34:247-256. [PMID: 25016397 DOI: 10.1016/j.semnephrol.2014.04.002]

Prevalence and determinants of resistant hypertension in the delta region of Egypt: A prospective observational study

Background and Aims

Hypertension (HTN) is a leading cause of morbidity and mortality affecting about 30%-40% of the adult population in developed countries. Fewer data were published about the prevalence, sociodemographics, and clinical characteristics of the resistant hypertensive population in Egypt. Hence, our aim is to focus the attention on these determinants especially in the delta region of Egypt.

Methods

Data belonging to patients visiting our HTN clinic in the Cardiovascular Department, Tanta University Hospital, Gharbeyah Governorate, Egypt, were collected over 12 months, between January 1, 2022, and 31 December 31, 2022, and then carefully analyzed.

Results

We found that the prevalence of resistant hypertension (RHTN) in the delta region of Egypt was 18%. We noted more RHTN cases in older age, that is, mean ± Std. was 51.5 ± 13.24 and 62.1 ± 7.56 for non-RHTN and RHTN, respectively. Also, the prevalence was higher in women representing about 54.4% of cases. Sixty-two percent of the patients with RH were obese (mean ± Std. of body mass index was 30.7 ± 5.36 in HTN and 47.7 ± 30.3 in RHTN groups with p value <0.001). We found a significant relationship between chronic kidney disease, diabetes, and RHTN.

Conclusion

Control of HTN among the Egyptian population in the delta region was unsatisfactory and higher than rates published globally. RH was more obvious in women, elderly, obese population, and diabetic and chronic kidney disease patients. Excessive use of nonsteroidal anti-inflammatory drugs, smoking, and high salt intake were clearly observed.

Overview of Methods to Differentiate Sympathetic Neurons from Human Pluripotent Stem Cells

Sympathetic neurons are crucial for maintenance of body homeostasis and regulation of all organs. Diseases can arise from malfunction of sympathetic neurons, including malignancies, hypertension, and genetic disorders. Human pluripotent stem cells (hPSCs) allow modeling of human diseases and the in-depth study of pathologies of specific cell types associated with such disorders. Advances in the ability to differentiate hPSCs in vitro has allowed the generation of specific cell types such as sympathetic neurons, which provides the novel opportunity to study diseases affecting the sympathetic nervous system in the human context. Here, we compare selected recent publications that have achieved the goal of generating sympathetic neurons from hPSCs. We discuss strengths and weaknesses of each approach and debate future improvements and the next steps for using these neurons to better our understanding of sympathetic neuron disorders and their treatments. © 2019 by John Wiley & Sons, Inc.

Induced pluripotent stem cells for disease modeling, cell therapy and drug discovery in genetic autonomic disorders: a review

The autonomic nervous system (ANS) regulates all organs in the body independent of consciousness, and is thus essential for maintaining homeostasis of the entire organism. Diseases of the ANS can arise due to environmental insults such as injury, toxins/drugs and infections or due to genetic lesions. Human studies and animal models have been instrumental to understanding connectivity and regulation of the ANS and its disorders. However, research into cellular pathologies and molecular mechanisms of ANS disorders has been hampered by the difficulties in accessing human patient-derived ANS cells in large numbers to conduct meaningful research, mainly because patient neurons cannot be easily biopsied and primary human neuronal cultures cannot be expanded.Human-induced pluripotent stem cell (hiPSC) technology can elegantly bridge these issues, allowing unlimited access of patient-derived ANS cell types for cellular, molecular and biochemical analysis, facilitating the discovery of novel therapeutic targets, and eventually leading to drug discovery. Additionally, such cells may provide a source for cell replacement therapy to replenish lost or injured ANS tissue in patients.Here, we first review the anatomy and embryonic development of the ANS, as this knowledge is crucial for understanding disease modeling approaches. We then review the current advances in human stem cell technology for modeling diseases of the ANS, recent strides toward cell replacement therapy and drug discovery initiatives.

Efficacy and safety of renal denervation for Chinese patients with resistant hypertension using a microirrigated catheter: study design and protocol for a prospective multicentre randomised controlled trial

INTRODUCTION

Available data show that approximately 8%-18% of patients with primary hypertension will develop resistant hypertension. In recent years, catheter-based renal denervation (RDN) has emerged as a potential treatment option for resistant hypertension. A number of observational studies and randomised controlled trials among non-Chinese patients have demonstrated its potential safety and efficacy.

METHODS AND ANALYSIS

This is a multicentre, randomised, open-label, parallel-group, active controlled trial that will investigate the efficacy and safety of a 5F saline-irrigated radiofrequency ablation (RFA) used for RDN in the treatment of Chinese patients with resistant hypertension. A total of 254 patients who have failed pharmacological therapy will be enrolled. Eligible subjects will be randomised in a 1:1 ratio to undergo RDN using the RFA plus antihypertensive medication or to receive treatment with antihypertensive medication alone. The primary outcome measure is the change in 24 hours average ambulatory systolic blood pressure from baseline to 3 months, comparing the RDN-plus-medication group with the medication-alone group. Important secondary endpoints include the change in office blood pressure from baseline to 6 months after randomisation. Safety endpoints such as changes in renal function will also be evaluated. The full analysis set, according to the intent-to-treat principle, will be established as the primary analysis population.

ETHICS AND DISSEMINATION

All participants will provide informed consent; the study protocol has been approved by the Independent Ethics Committee for each site. This study is designed to investigate the efficacy and safety of RDN using a 5F saline microirrigated RFA. Findings will be shared with participating hospitals, policymakers and the academic community to promote the clinical management of resistant hypertension in China.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT02900729; pre-results.

Device-based Therapy for Hypertension

Hypertension continues to be a major contributor to global morbidity and mortality, fuelled by an abundance of patients with uncontrolled blood pressure despite the multitude of pharmacological options available. This may occur as a consequence of true resistant hypertension, through an inability to tolerate current pharmacological therapies, or non-adherence to antihypertensive medication. In recent years, there has been a rapid expansion of device-based therapies proposed as novel non-pharmacological approaches to treating resistant hypertension. In this review, we discuss seven novel devices—renal nerve denervation, baroreflex activation therapy, carotid body ablation, central iliac arteriovenous anastomosis, deep brain stimulation, median nerve stimulation, and vagal nerve stimulation. We highlight how the devices differ, the varying degrees of evidence available to date and upcoming trials. This review also considers the possible factors that may enable appropriate device selection for different hypertension phenotypes.

Hypertension in the Kidney Transplant Recipient: Overview of Pathogenesis, Clinical Assessment, and Treatment

Cardiovascular disease is the leading cause of death in patients with chronic renal disease and the most common cause of death and allograft loss among kidney transplant recipients. Transplant patients often have multiple cardiovascular risk factors antedating transplantation. Among the most prominent is hypertension (HTN), which affects at least 90% of transplant patients. Uncontrolled HTN is an independent risk factor for allograft loss. The etiology of HTN in transplant recipients is complex and multifactorial, including the use of essential immunosuppressive medications. Post-transplant HTN management requires a systematic and individualized approach with nonpharmacologic and pharmacologic therapies. There is no single ideal agent or treatment algorithm. Patients should regularly monitor and record their blood pressure at home. Often, multiple antihypertensive drugs are needed to achieve a goal blood pressure of 120-140/70-90 mm Hg. As transplant recipients commonly must take 8 to 12 different medications daily, adherence must be continually encouraged and monitored. Special attention must be paid to potential drug side effects and drug interactions with immunosuppressive medications.

Endocrine Tumors Causing Arterial Hypertension: Pathophysiological Mechanisms and Clinical Implications

Some tumors are a relatively rare and amendable cause of hypertension, often associated with a higher cardiovascular morbidity and mortality, as compared with that of both general population and patients with essential hypertension. This worse prognosis is not entirely related to blood pressure increase, because the release of substances from the tumor can directly influence blood pressure behavior. Diagnostic approach is challenging and needs a deep knowledge of the different neuro-hormonal and genetic mechanisms determining blood pressure increase. Surgical tumor removal can, but not always, cause blood pressure normalization, depending on how early was tumor detection, since a long-standing history of hypertension is often associated with a much weaker effect on blood pressure. Moreover, target organ damage can be affected by the substances themselves released by the tumors as well as by tumor removal. In this review we consider the phenotype and genetic features of patients with tumor-induced hypertension and focus on their diagnostic work-up.

Plasma membrane calcium ATPases (PMCAs) as potential targets for the treatment of essential hypertension

The incidence of hypertension, the major modifiable risk factor for cardiovascular disease, is increasing. Thus, there is a pressing need for the development of new and more effective strategies to prevent and treat hypertension. Development of these relies on a continued evolution of our understanding of the mechanisms which control blood pressure (BP). Resistance arteries are important in the regulation of total peripheral resistance and BP; changes in their structure and function are strongly associated with hypertension. Anti-hypertensives which both reduce BP and reverse changes in resistance arterial structure reduce cardiovascular risk more than therapies which reduce BP alone. Hence, identification of novel potential vascular targets which modify BP is important. Hypertension is a multifactorial disorder which may include a genetic component. Genome wide association studies have identified ATP2B1, encoding the calcium pump plasma membrane calcium ATPase 1 (PMCA1), as having a strong association with BP and hypertension. Knockdown or reduced PMCA1 expression in mice has confirmed a physiological role for PMCA1 in BP and resistance arterial regulation. Altered expression or inhibition of PMCA4 has also been shown to modulate these parameters. The mechanisms whereby PMCA1 and 4 can modulate vascular function remain to be fully elucidated but may involve regulation of intracellular calcium homeostasis and/or comprise a structural role. However, clear physiological links between PMCA and BP, coupled with experimental studies directly linking PMCA1 and 4 to changes in BP and arterial function, suggest that they may be important targets for the development of new pharmacological modulators of BP.

The double challenge of resistant hypertension and chronic kidney disease

Resistant hypertension is defined as blood pressure above goal despite adherence to a combination of at least three optimally dosed antihypertensive medications, one of which is a diuretic. Chronic kidney disease is the most frequent of several patient factors or comorbidities associated with resistant hypertension. The prevalence of resistant hypertension is increased in patients with chronic kidney disease, while chronic kidney disease is associated with an impaired prognosis in patients with resistant hypertension. Recommended low-salt diet and triple antihypertensive drug regimens that include a diuretic, should be complemented by the sequential addition of other antihypertensive drugs. New therapeutic innovations for resistant hypertension, such as renal denervation and carotid barostimulation, are under investigation especially in patients with advanced chronic kidney disease. We discuss resistant hypertension in chronic kidney disease stages 3-5 (ie, patients with an estimated glomerular filtration rate below 60 mL/min per 1·73 m(2) and not on dialysis), in terms of worldwide epidemiology, outcomes, causes and pathophysiology, evidence-based treatment, and a call for action.

Drug therapy of apparent treatment-resistant hypertension: focus on mineralocorticoid receptor antagonists

Apparent treatment-resistant hypertension (aTRH) is defined as blood pressure (BP) >140/90 mmHg despite three different antihypertensive drugs including a diuretic. aTRH is associated with an increased risk of cardiovascular events, including stroke, chronic renal failure, myocardial infarction, congestive heart failure, aortic aneurysm, atrial fibrillation, and sudden death. Preliminary studies of renal nerve ablation as a therapy to control aTRH were encouraging. However, these results were not confirmed by the Symplicity 3 trial. Therefore, attention has refocused on drug therapy. Secondary forms of hypertension and associated conditions such as obesity, sleep apnea, and primary aldosteronism are common in patients with aTRH. The pivotal role of aldosterone in the pathogenesis of aTRH in many cases is well recognized. For patients with aTRH, the Joint National Committee-8, the European Society of Hypertension, and a recent consensus conference recommend that a diuretic, ACE inhibitor, or angiotensin receptor blocker and calcium channel blocker combination be used to maximally tolerated doses before starting a 'fourth-line' drug such as a mineralocorticoid receptor (MR) antagonist. Although the best fourth-line drug for aTRH has not been extensively investigated, a number of studies summarized here show that an MR antagonist is effective in reducing BP when added to the standard multi-drug regimen.

Endocrine hypertension: An overview on the current etiopathogenesis and management options

Endocrine causes of secondary hypertension include primary aldosteronism, pheochromocytoma, cushing’s syndrome, hyperparathyroidism and hypo- and hyperthyroidism. They comprise 5%-10% of the causes of secondary hypertension. Primary hyperaldosteronism, the most common of the endocrine cause of hypertension often presents with resistant or difficult to control hypertension associated with either normo-or hypokalemia. Pheochromocytoma, a great mimicker of many conditions, is associated with high morbidity and mortality if left untreated. A complete history including pertinent family history, physical examination along with a high index of suspicion with focused biochemical and radiological evaluation is important to diagnose and effectively treat these conditions. The cost effective targeted genetic screening for current known mutations associated with pheochromocytoma are important for early diagnosis and management in family members. The current review focuses on the most recent evidence regarding causes, clinical features, methods of diagnosis, and management of these conditions. A multidisciplinary approach involving internists, endocrinologists and surgeons is recommended in optimal management of these conditions.

Acute blood pressure changes are related to chronic effects of resistance exercise in medicated hypertensives elderly women

BACKGROUND

A previous study observed that the chronic effects of aerobic training on blood pressure (BP) are related to acute BP responses after a single bout of aerobic exercise. However, whether similar responses are observed with resistance exercise (RE) remains obscure. Thus, this study analysed the relationship between the acute BP responses to a single bout of RE and chronic changes in resting BP after a RE training in medicated hypertensive elderly women.

METHODS AND RESULTS

Twenty medicated hypertensive women participated in the study. They underwent an acute RE bout where BP and heart rate (HR) were obtained at rest and for 60 min after the RE. Subsequently, the participants underwent a progressive RE training for 12 weeks at 60-80% of maximal strength test. Resting BP and HR were also obtained after the RE training. The chronic decreases in systolic and diastolic BP were significantly greater in the participants who experienced acutely decreased systolic and diastolic BP, respectively (P<0·05). The changes in systolic BP after acute RE were correlated with the chronic changes in resting systolic BP after RE training (r = 0·47; P = 0·03). Similar correlations between acute and chronic responses were also observed for diastolic BP (r = 0·70; P = 0·01), mean BP (r = 0·58; P = 0·01), HR (r = 0·73; P<0·01) and RPP (r = 0·52; P = 0·01).

CONCLUSION

Similar to previously work involving aerobic exercise, BP responses to a single bout of RE are strongly related to chronic effects of RE training on BP in medicated hypertensive elderly women.