High prevalence of cardiac and extracardiac target organ damage in refractory hypertension

Revisiting resistant hypertension in kidney disease

PURPOSE OF REVIEW

As compared to controlled or uncontrolled hypertension, resistant hypertension in patients with chronic kidney disease (CKD) poses a significantly increased healthcare burden due to greater target end-organ damage including cardiovascular disease and CKD progression. Patients with CKD have two to three times higher risk of developing resistant hypertension. True resistant hypertension needs to be distinguished from apparent treatment resistant hypertension (aTRH); however, it is usually not possible in epidemiological studies. Moreover, impact of contemporary guidelines changes in the target blood pressure (BP) goal to less than 130/80 mmHg remains to be determined.

RECENT FINDINGS

Up to half of patients with CKD meet aTRH criteria using 2017 ACC/AHA target BP less than 130/80 mmHg. Excess sodium retention in extracellular and tissue compartment remains the cornerstone cause of resistance to the treatment in CKD. Maximizing and optimizing the diuretic regimen in addition to dietary sodium restriction plays a critical role in these patients. Management requires a trustworthy provider-patient relationship facilitating identification and intervention for the barriers restricting the uptake of lifestyle modifications and medications. Recently, renal denervation has been approved and many other novel agents are on the horizon for treatment of true resistant hypertension associated with CKD.

SUMMARY

This review discusses the latest in the pathophysiology, definition, identification and treatment strategies of resistant hypertension in individuals with CKD. Further investigations are required to identify the prevalence, future implication and treatment outcome data for true resistant hypertension associated with CKD.

The Global Burden of Resistant Hypertension and Potential Treatment Options

Resistant hypertension (RH) is defined as systolic blood pressure (SBP) or diastolic blood pressure (DBP) that remains .140 mmHg or .90 mmHg, respectively, despite an appropriate lifestyle and the use of optimal or maximally tolerated doses of a three-drug combination, including a diuretic. This definition encompasses the category of controlled RH, defined as the presence of blood pressure (BP) effectively controlled by four or more antihypertensive agents, as well as refractory hypertension, referred to as uncontrolled BP despite five or more drugs of different classes, including a diuretic. To confirm RH presence, various causes of pseudo-resistant hypertension (such as improper BP measurement techniques and poor medication adherence) and secondary hypertension must be ruled out. Inadequate BP control should be confirmed by out-of-office BP measurement. RH affects about 5% of the hypertensive population and is associated with increased cardiovascular morbidity and mortality. Once RH presence is confirmed, patient evaluation includes identification of contributing factors such as lifestyle issues or interfering drugs/substances and assessment of hypertension-mediated organ damage. Management of RH comprises lifestyle interventions and optimisation of current medication therapy. Additional drugs should be introduced sequentially if BP remains uncontrolled and renal denervation can be considered as an additional treatment option. However, achieving optimal BP control remains challenging in this setting. This review aims to provide an overview of RH, including its epidemiology, pathophysiology, diagnostic work-up, as well as the latest therapeutic developments.

Resistant hypertension: Diagnosis, evaluation, and treatment practical approach

The term RH describes a subgroup of hypertensive patients whose BP is uncontrolled despite the use of at least three antihypertensive drugs in an appropriate combination at optimal or best tolerated doses. True RH is considered when appropriate lifestyle measures and treatment with optimal or best tolerated doses of three or more drugs (a thiazide/thiazide-like diuretic, plus renin-angiotensin system -RAS- blocker and a calcium channel blocker -CCB-) fail to lower office BP to <140/90 mmHg; besides the inadequate BP control should be confirmed by home blood pressure monitoring (HBPM) or 24-hour ambulatory; and evidence of adherence to therapy and exclusion of secondary causes of hypertension are required. RH patients are at a high risk of cardiovascular events and death. RH is associated with a higher prevalence of end-organ damage. When stricter criteria are applied, a reasonable estimate of the prevalence of true RH is 5 % of the total hypertensive population. The predominant hemodynamic pattern appears to be increased systemic vascular resistance and plasma volume with normal or even low cardiac output. We must rule out pseudo-resistance before diagnosing true drug resistance. RH is a therapeutic challenge, and its management includes lifestyle interventions, avoiding nonadherence to treatment, avoiding inertia, appropriate use of antihypertensive drugs based on current evidence, especially long-acting diuretics, and the addition of mineralocorticoid receptor antagonists. RCTs to identify the most protective medical therapy in RH are needed. A series of drugs in different stages of investigation could significantly impact RH treatment in the future.

Management of Resistant Hypertension

Resistant hypertension (RH) is a severe form of hypertension associated with increased cardiovascular risk. Although true RH affects less than 10% of the patients receiving antihypertensive therapy, the absolute number is high and continues to increase. The workup of these patients requires screening for secondary hypertension and pseudoresistance, including poor adherence to prescribed medicines and the white-coat phenomenon. The treatment of RH consists of lifestyle modifications and pharmacological therapies. Lifestyle modifications include dietary adjustments, weight loss, physical activity, and limiting alcohol consumption; pharmacological therapies include diuretics, mineralocorticoid receptor antagonists, beta blockers, angiotensin receptor-neprilysin inhibitors, and others. Over the last 15 years, interventional approaches have emerged as adjunct treatment options; we highlight catheter-based renal denervation. This review summarizes the rationales and latest clinical evidence and, based thereon, proposes an updated algorithm for the management of RH.

Association between Resistant Arterial Hypertension, Type 2 Diabetes, and Selected microRNAs

INTRODUCTION

In recent years, a very close relationship between miRNA and cardiovascular diseases has been found. RAH and T2DM are accompanied by a change in the microRNA expression spectrum.

OBJECTIVES

This study aimed to evaluate the clinical characteristics and expression of selected microRNAs in patients with idiopathic RAH and T2DM.

PATIENTS AND METHODS

A total of 115 patients with RAH were included in this study. Among them were 53 patients (46.09%) with T2DM. miRNA levels were determined using quantitative real-time polymerase chain reaction. The expression of the examined genes was calculated from the formula RQ = 2-ΔΔCT.

RESULTS

Analysis using the Mann-Whitney U test showed a statistically significant (p < 0.05) difference in the expression of MIR1-1 (p = 0.031) and MIR195 (p = 0.042) associated with the occurrence of T2DM in the subjects. The value of MIR1-1 gene expression was statistically significantly higher in patients with T2DM (median: 0.352; mean: 0.386; standard deviation: 0.923) compared to patients without T2DM (median: 0.147; mean: -0.02; standard deviation: 0.824). The value of MIR195 gene expression was statistically significantly higher in patients with T2DM (median: 0.389, mean: 0.442; standard deviation: 0.819) compared to patients without T2DM (median: -0.027; mean: 0.08; standard deviation: 0.942).

CONCLUSIONS

The values of MIR1-1 and MIR195 gene expression were statistically significantly higher in patients with RAH and T2DM compared to patients with RAH and without T2DM. Further studies are necessary to precisely clarify the roles of miRNAs in patients with RAH and T2DM. They should demonstrate the utility of these genetic markers in clinical practice.

Controversies in Hypertension V: Resistant and Refractory Hypertension

Apparent resistant hypertension, defined as uncontrolled office blood pressure despite ≥ 3 antihypertensive medications including a diuretic or use of ≥ 4 medications regardless of blood pressure, occurs in ≤ 15% of treated hypertensives. Apparent refractory hypertension, defined as uncontrolled office pressure despite use of 5 or more medications including a diuretic, occurs in ≤ 10% of resistant cases. Both are associated with increased comorbidity and enhanced cardiovascular risk. To rule out pseudo-resistant or pseudo-refractory hypertension, employ guideline-based methodology for obtaining pressure, maximize the regimen, rule out white-coat effect, and assess adherence. True resistant hypertension is characterized by volume overload and aldosterone excess, refractory by enhanced sympathetic tone. Spironolactone is the preferred agent for resistance, with lower doses. Spironolactone, potassium binders, or both, are preferred if the estimated glomerular filtration rate is below 45. If significant albuminuria, finerenone is indicated. The optimal treatment of refractory hypertension is unclear, but sympathetic inhibition (α-β blockade, centrally acting sympathoinhibitors, or both) seems reasonable. Renal denervation has shown minimal benefit for resistance, but its role in refractory hypertension remains to be defined.

Application of myocardial work in predicting adverse events among patients with resistant hypertension

BACKGROUND

Hypertension is the most common chronic disease and the leading risk factor for disability and premature deaths worldwide. Approximately 10-20% of all patients with hypertension and 15-18% of the general population who are treated for hypertension have resistant hypertension (RH). Patients with RH have a higher risk of end-organ damage, such as carotid intima-media thickening, retinopathy, left ventricular hypertrophy and heart failure, myocardial infarction, stroke, impaired renal function, and death than those with controlled blood pressure. In the present study, we applied echocardiography to patients with RH to evaluate myocardial work (MW) and determine whether it is predictive for the occurrence of adverse events within 3 years.

METHODS

We included 283 outpatients and inpatients aged ≥ 18 years who met the clinical criteria for RH, without arrhythmia and severe aortic valve stenosis, between July 2018 and June 2019. The patients were followed up for 3 years from starting enrollment, and any adverse event that occurred during the period was used as the observation end point. Each enrolled patient underwent a complete transthoracic echocardiogram examination, blood pressure was measured and recorded, and MW was then analyzed.

RESULTS

Eighty-two (28.98%) patients with RH had adverse events, such as myocardial infarction (n = 29, 35.36%), heart failure (n = 4, 0.05%), renal insufficiency (n = 40, 48.78%), renal failure (n = 2, 0.02%), cerebral infarction (n = 5, 0.06%), and cerebral hemorrhage (n = 2, 0.02%), and no death events occurred. In patients with RH and adverse events, global longitudinal strain (GLS) (- 16% vs. - 18%), the global work index (2079 mmHg% vs. 2327 mmHg%), global constructive work (2321 mmHg% vs. 2610 mmHg%), and global work efficiency (93% vs. 94%) were lower than those in patients without adverse events. However, global wasted work (GWW) was higher in patients with RH and adverse events than in those without adverse events (161 mmHg% vs. 127 mmHg%). GLS and GWW were the most significant in predicting adverse events.

CONCLUSIONS

MW, especially GLS and GWW, is a good method to predict 3-year adverse events in patients with RH.

What is resistant arterial hypertension?

PURPOSE

The current review is to describe the definition and prevalence of resistant arterial hypertension (RAH), the difference between refractory hypertension, patient characteristics and major risk factors for RAH, how RAH is diagnosed, prognosis and outcomes for patients.

MATERIALS AND METHODS

According to the WHO, approximately 1.28 billion adults aged 30-79 worldwide have arterial hypertension, and over 80% of them do not have blood pressure (BP) under control. RAH is defined as above-goal elevated BP despite the concurrent use of 3 or more classes of antihypertensive drugs, commonly including a long-acting calcium channel blocker, an inhibitor of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a thiazide diuretic administered at maximum or maximally tolerated doses and at appropriate dosing frequency. RAH occurs in nearly 1 of 6 hypertensive patients. It often remains unrecognised mainly because patients are not prescribed ≥3 drugs at maximal doses despite uncontrolled BP.

CONCLUSION

RAH distinctly increases the risk of developing coronary artery disease, heart failure, stroke and chronic kidney disease and confers higher rates of major adverse cardiovascular events as well as increased all-cause mortality. Timely diagnosis and treatment of RAH may mitigate the associated risks and improve short and long-term prognosis.

Novel Dual Endothelin Inhibitors in the Management of Resistant Hypertension

Resistant hypertension (RH) is defined as the failure to achieve blood pressure control despite using triple combination therapy with a renin-angiotensin system inhibitor (RAS-i), a calcium antagonist, and a diuretic. The endothelin (ET) system is implicated in the regulation of vascular tone, primarily through vasoconstriction, intervenes in cardiac contractility with inotropic effects, and contributes to water and sodium renal reabsorption. ET inhibitors, currently approved for the treatment of pulmonary hypertension, seem to be also useful for essential hypertension and RH as well. Studies into the development of new dual ET inhibitors, which inhibit both type A and B ET (ETA and ETB) receptors, present initial results of managing RH. Aprocitentan (ACT-132577) is a novel, orally active and well tolerated dual ET receptor antagonist, which has been examined in several experimental studies and clinical trials with promising results for RH control. The recent publication of the large PRECISION study in The Lancet journal provides further reassurance regarding the efficacy and safety of aprocitentan for RH, with the aim of overcoming unmet needs in the management of this difficult group of patients.

The effect of combining therapeutic drug monitoring of antihypertensive drugs with personalised feedback on adherence and resistant hypertension: the (RHYME-RCT) trial protocol of a multi-centre randomised controlled trial

BACKGROUND

Adherence to antihypertensive drugs (AHDs) is important for adequate blood pressure control. Not taking these drugs as prescribed is one of the main underlying causes for resistant hypertension (RH), which in turn leads to an increased risk of cardiovascular events, stroke and kidney damage. Therefore, correct identification of patients that are non-adherent to AHDs is crucial to improve clinical outcome. For this goal, therapeutic drug monitoring is the most reliable method. The primary objective of this trial is to investigate whether monitoring of drug concentrations with a dried blood spot (DBS) sampling method combined with personalised feedback leads to a decrease in prevalence of RH after 12 months due to an increase in adherence. Secondary objectives include the difference over time in the number of required AHDs as well as the defined daily dose (DDD). Lastly, the cost-utility of SoC versus the intervention in RH is determined.

METHODS

This is a multi-centre single-blinded randomised controlled trial (RHYME-RCT). First, at an eligibility visit, DBS sampling, to monitor drug concentrations in blood, and a 24-h ambulatory blood pressure measurement (24-h ABPM) are performed simultaneously. Patients with a daytime systolic blood pressure (SBP) > 135 and/or diastolic blood pressure (DBP) > 85 mmHg are randomised to SoC or intervention + SoC. The intervention is performed by the treating physician and includes information on drug concentrations and a comprehensive personalised feedback conversation with the use of a communication tool. The follow-up period is one year with visits at 3, 6 and 12 months randomisation and includes 24-h ABPM and DBS sampling.

DISCUSSION

This will be the first trial that focusses specifically on patients with RH without taking into account suspicion of non-adherence and it combines monitoring of AHD concentrations to identify non-adherence to AHDs with a comprehensive feedback to improve non-adherence. Furthermore, if this trial shows positive outcomes for the intervention it can be directly implemented in clinical practice, which would be a great improvement in the treatment of RH.

TRIAL REGISTRATION

RHYME-RCT is registered in the Dutch Trial Register on 27/12/2017 (NTR6914) and can be found in the International Clinical Trials Registry Platform.

Promise of Physiological Profiling to Prevent Stroke in People of African Ancestry: Prototyping Ghana

PURPOSE OF REVIEW

Worldwide, compared to other racial/ethnic groups, individuals of African ancestry have an excessively higher burden of hypertension-related morbidities, especially stroke. Identifying modifiable biological targets that contribute to these disparities could improve global stroke outcomes. In this scoping review, we discuss how pathological perturbations in the renin-angiotensin-aldosterone pathways could be harnessed via physiological profiling for the purposes of improving blood pressure control for stroke prevention among people of African ancestry.

RECENT FINDINGS

Transcontinental comparative data from the USA and Ghana show that the prevalence of treatment-resistant hypertension among stroke survivors is 42.7% among indigenous Africans, 16.1% among African Americans, and 6.9% among non-Hispanic Whites, p < 0.0001. A multicenter clinical trial of patients without stroke in 3 African countries (Nigeria, Kenya, and South Africa) demonstrated that physiological profiling using plasma renin activity and aldosterone to individualize selection of antihypertensive medications compared with usual care resulted in better blood pressure control with fewer medications over 12 months. Among Ghanaian ischemic stroke survivors treated without renin-aldosterone profiling data, an analysis revealed that those with low renin phenotypes did not achieve any meaningful reduction in blood pressure over 12 months on 3-4 antihypertensive medications despite excellent adherence. For a polygenic condition such as hypertension, individualized therapy based on plasma renin-aldosterone-guided selection of therapy for uncontrolled BP following precision medicine principles may be a viable strategy for primary and secondary stroke prevention with the potential to reduce disparities in the poor outcomes of stroke disproportionately shared by individuals of African ancestry. A dedicated clinical trial to test this hypothesis is warranted.

The relationship between mean platelet volume and resistant hypertension

OBJECTIVE

Resistant hypertension (RH) is associated with an increased risk of cardiovascular events.Mean platelet volume (MPV) has been shown to indicate platelet activation and is associated with increased cardiovascular disease risk. In our study, we aimed to evaluate the relationship between mean platelet volume and resistant hypertension.

METHOD

A total of 279 patientswere included in our study and divided into three groups (GroupI: seventy-eight patients with resistant hypertension, group II: seventy-nine patients with controlled hypertension and group III: one-hundred-five patients without hypertension). Routine laboratory tests and ambulatory blood pressure measurement (ABPM) were followed up in all patients.

RESULTS

Of the patients in the study, 25% were female while 75% were male, and the mean age was 56.5 ± 11.8 years. The mean MPV values were found to be 9.34 ± 1.49 fL in the RHT group, 8.82 ± 0.83 fLin the controlled HT group, and 8.5 ± 0.85 fL in the normotensive individuals, and there was a significant correlation between the RHT group and the other groups (RHT versus controlled HT p1 = 0.008, RHT versus normotensive individuals p2 < 0,001). When we compared controlled HT and normotensive individuals, no significant relationship was found between MPV values (p3 = 0,157).

CONCLUSION

The MPV value was found to be higher in resistant hypertensive patients compared to controlled hypertensive and normotensive patients. MPV values can be used to predict adverse cardiovascular events in RHT patients.

Treatment-resistant hypertension

Treatment-resistant hypertension is one of the most significant causes of poor blood pressure regulation. Patients with resistant hypertension are at a higher risk of developing comorbidities compared to the general hypertensive population. As a result, these patients have an increased incidence of disability and premature death, as well as increased treatment costs. Due to the above-mentioned, in the last decade, there has been an increase in researchers' interest in elucidating the pathogenesis, diagnosis, and treatment of resistant hypertension. However, recent data indicate that 20% of female and 24% of male patients with arterial hypertension still have uncontrolled blood pressure, despite maximum doses of three antihypertensive drugs (including a diuretic) and appropriate lifestyle measures. New treatment modalities (i.e. devicebased interventions - catheter-based renal denervation and baroreceptor stimulation) offer hope for achieving adequate blood pressure regulation in these patients. In this paper, we have summarized previous knowledge about the mechanisms underlying the pathogenesis of resistant hypertension, as well as optimal diagnostic methods to differentiate true from pseudo-resistant hypertension. We have also given an overview of the current therapeutic approach, including optimal medical therapy and new treatment modalities (i.e. device-based interventions) and their role in the treatment of resistant hypertension.

Prognostic value of masked uncontrolled apparent resistant hypertension detected through home blood pressure monitoring

OBJECTIVE

Resistant hypertension carries a poor prognosis and current guidelines recommend the exclusion of the white-coat phenomenon for proper diagnosis. However, guidelines do not focus on patients treated with at least three drugs whose blood pressure (BP) is controlled at the office but elevated out of it. We aimed at determining whether this masked uncontrolled apparent resistant hypertension (MUCRH) detected through home blood pressure monitoring (HBPM) has prognostic value for fatal and nonfatal events in these hypertensive patients.

METHODS

Hypertensive patients treated with at least three drugs who performed a baseline HBPM between 2008 and 2015 were followed to register the occurrence of total mortality, cardiovascular mortality, and fatal and nonfatal cardiac and cerebrovascular events. MUCRH was defined as office blood pressure less than 140/90 mmHg and home BP at least 135 and/or 85 mmHg. Multivariable Cox proportional hazard models were adjusted to determine the independent prognostic value of MUCRH for the events of interest.

RESULTS

We included 470 patients, 35.5% male, mean age 71.9 years, and treated with 3.3 antihypertensive drugs on average. Among study population, 15.5% had MUCRH (33.3% when considering only patients with adequate BP control at the office). Median follow-up was 6.7 years. In multivariable models, MUCRH was an independent predictor for cardiovascular mortality and cerebrovascular events: hazard ratio 4.9 (95% CI 1.2-19.9, P = 0.03) and 5.1 (95% CI 1.5-16.9, P = 0.01), respectively.

CONCLUSION

MUCRH is not rare and is independently associated with cardiovascular morbidity and mortality. The systematic monitoring of intensively treated individuals through HBPM would be useful for the detection of patients at increased risk of events.

Association of treatment-resistant hypertension defined by home blood pressure monitoring with cardiovascular outcome

In diagnosis of treatment-resistant hypertension (TRH), guidelines recommend out-of-office blood pressure (BP) measurements, ambulatory BP monitoring (ABPM) and home BP monitoring (HBPM). Although evidence of an association between ABPM-evaluated TRH and cardiovascular disease (CVD) prognosis has accumulated, data are sparse regarding HBPM-evaluated TRH. We investigated this issue using data from the nationwide practice-based J-HOP (Japan Morning-Surge Home BP) study, which recruited 4,261 outpatients (mean age 64.9 years; 46.8% men; 91.5% hypertensives) who underwent morning and evening HBPM for 14 days. During 6.2 ± 3.8 years (26,418 person-years) follow-up, 270 total CVDs (stroke, coronary artery disease, aortic dissection, and heart failure) occurred. The adjusted hazard ratio (HR) (95% CIs) of uncontrolled TRH, i.e., uncontrolled BP using 3 classes of medications including diuretics or ≥4 classes of medications, for total CVD risk compared to controlled BP using <3 classes were 2.02 (1.38-2.94) and 1.81 (1.23-2.65) in home BP of 135/85 mmHg and 130/80 mmHg, respectively. Additionally, patients with TRH defined by guidelines, i.e., uncontrolled BP using 3 classes of medications including diuretics or controlled/uncontrolled BP using ≥4 classes of medications, also had higher total CVD risk compared to non-TRH under all home BP criteria. Moreover, in patients with uncontrolled apparent-TRH, i.e., TRH defined by office BP, uncontrolled home BP (≥135/85 mmHg) was still associated with atherosclerotic CVD (CVDs except heart failure) risk (adjusted HR [95% CI], 2.38 [1.09-5.19]). This is the first study to demonstrate an independent association between TRH evaluated by HBPM and CVD outcomes.

Novel surgical approach for removing intraretinal loculated foveal hemorrhage in a patient with hypertensive retinopathy

Purpose

To present a surgical approach for removing intra-retinal loculated foveal hemorrhage due to hypertensive retinopathy (HR) in a patient with uncontrolled hypertension (HTN).

Observations

A 67-year-old man presented to a tertiary retina clinic with the complaint of decreased vision in his left eye (OS) for the past six months. He had a history of uncontrolled HTN, which caused HR; otherwise, his past medical and ocular history were insignificant. His best-corrected visual acuity (BCVA) was 20/20 right eye (OD) and 20/400 OS. Fundus examination of OD did not show significant pathology except mild arterial narrowing. Fundus examination of OS revealed arterial narrowing and multiple areas of small retinal hemorrhage. Old, organized hemorrhage with a yellow foveal centered lesion appearance was detected on fundus examination. Spectral-domain optical coherence tomography (SD-OCT) showed a dense hyper-reflective intra-retinal lesion at the fovea. Pars plana vitrectomy was performed. Internal limiting membrane (ILM) was stained with Brilliant Blue G (BBG) and peeled off around the lesion using ILM forceps. Attempts to remove the lesion with cannula-assisted active backflush and aspiration were unsuccessful. Therefore, the lesion was gently dissected and extracted by using 41-gauge needle. After removing the clot, the rotational ILM flap technique was used to repair the developed macular hole-like tissue defect. At the two-month follow-up visit, BCVA improved considerably to 20/50, and significant anatomical restoration was observed.

Conclusion and Importance

HR is relatively common among patients with elevated blood pressure. To date, management of HR and its complications such as retinal hemorrhage is limited to non-surgical methods. For the first time, a surgical approach is utilized to manage one of the HR's complications with prominent visual and structural improvement. The index case report presents a new management option for hypertensive retinal hemorrhage, but only in appropriate patients with ocular indications and understanding of the potential adverse events associated with the surgical procedure.

Eligibility for Baroreflex Activation Therapy and medication adherence in patients with apparently resistant hypertension

Uncontrolled hypertension is a main risk factor for cardiovascular morbidity. Baroreflex activation therapy (BAT) is an effective therapy option addressing true resistant hypertension. We evaluated patients’ eligibility for BAT in a staged assessment as well as adherence to antihypertensive drug therapy. Therefore, we analyzed files of 345 patients, attending the hypertension clinic at University Medicine Göttingen. Additionally, gas chromatographic‐mass spectrometric urine analyses of selected individuals were performed evaluating their adherence. Most common cause for a revoked BAT recommendation was blood pressure (BP) control by drug adjustment (54.2%). Second leading cause was presence of secondary hypertension (31.6%). Patients to whom BAT was recommended (59 (17.1%)) were significantly more often male (67.8% vs. 43.3%, P = .0063), had a higher body mass index (31.8 ± 5.8 vs. 30.0 ± 5.7 kg/m², P = .0436), a higher systolic office (168.7 ± 24.7 vs. 147.7 ± 24.1 mmHg, P < .0001), and 24h ambulatory BP (155.0 ± 14.6 vs. 144.4 ± 16.8 mmHg, P = .0031), took more antihypertensive drugs (5.8 ± 1.3 vs. 4.4 ± 1.4, P < .0001), and suffered more often from numerous concomitant diseases. Eventually, 27 (7.8%) received a BAT system. In the toxicological analysis of 75 patients, mean adherence was 75.1%. 16 patients (21.3%) showed non‐adherence. Thus, only a small number of patients eventually received a BAT system, as treatable reasons for apparently resistant hypertension could be identified frequently. This study is—to our knowledge—the first report of a staged assessment of patients’ suitability for BAT and underlines the need for a careful examination and indication. Non‐adherence was proven to be a relevant issue concerning apparently resistant hypertension and therefore non‐eligibility for interventional antihypertensive therapy.

We evaluated the eligibility for baroreflex activation therapy (BAT) of 345 patients, attending the hypertension clinic at University Medicine Göttingen. Patients’ drug adherence was investigated by 75 toxicological analyses. Most common cause for a revoked BAT recommendation was blood pressure control by drug adjustment. Eventually, only less patients (7.8%) received a BAT system. Patients receiving a BAT recommendation showed specific characteristics and suffered numerous comorbidities, leading to a high cardiovascular risk, and therefore seem to greatly benefit from BAT implantation. 21.3% of patients showed non‐adherence, proving non‐adherence to be a relevant issue.

Drug-resistant hypertension in primary aldosteronism patients undergoing adrenal vein sampling: the AVIS-2-RH study

AIMS

We aimed at determining the rate of drug-resistant arterial hypertension in patients with an unambiguous diagnosis of primary aldosteronism (PA). Moreover, we sought for investigating the diagnostic performance of adrenal vein sampling (AVS), and the effect of adrenalectomy on blood pressure (BP) and prior treatment resistance in PA patients subtyped by AVS in major referral centres.

METHODS AND RESULTS

The Adrenal Vein Sampling International Study-2 (AVIS-2) was a multicentre international study that recruited consecutive PA patients submitted to AVS, according to current guidelines, during 15 years. The patients were over 18 years old with arterial hypertension and had an unambiguous diagnosis of PA. The rate of resistant hypertension was assessed at baseline and after adrenalectomy using the American Heart Association (AHA) 2018 definition. Information on presence or absence of resistant hypertension was available in 89% of the 1625 enrolled PA patients. Based on the AHA 2018 criteria, resistant hypertension was found in 20% of patients, of which about two-thirds (14%) were men and one-third (6%) women (χ2 = 17.1, P < 1*10-4) with a higher rate of RH in men than in women (23% vs. 15% P < 1*10-4). Of the 292 patients with resistant hypertension, 98 (34%) underwent unilateral AVS-guided adrenalectomy, which resolved BP resistance to antihypertensive treatment in all.

CONCLUSIONS

(i) Resistant hypertension is a common presentation in patients seeking surgical cure of PA; (ii) AVS is key for the optimal management of patients with PA due to resistant hypertension; and (iii) AVS-guided adrenalectomy allowed resolution of treatment-resistant hypertension.

Role of endothelial function determined by asymmetric dimethylarginine in the prediction of resistant hypertension: A subanalysis of ReHOT trial

The authors conducted a subanalysis of the ReHOT (Resistant Hypertension Optimal Treatment) study to evaluate the association between endothelial dysfunction and resistant hypertension in a population of patients treated in a staged fashion for hypertension. One hundred and three hypertensive patients were followed for 6 months and participated in seven visits (V0-V6) 28 days apart. There was a first phase (V0-V3) of antihypertensive adjustment with three drugs and determination of resistant hypertension and a second randomized phase (V3-V6) of treatment with a fourth drug (clonidine or spironolactone) in the hypertensive patients characterized as resistant. Of the 103 patients included, 86 (83.5%) underwent the randomization visit (V3), 71 were characterized as non-resistant hypertensives (82.5%), and 15 as resistant hypertensives (17.5%). Serum asymmetric dimethylarginine (ADMA) was shown to be an independent predictor of resistant hypertension after adjustment for multiple variables (OR: 11.42, 95% CI: 1.02-127.71, P = .048), and in addition, there was a reduction in blood pressure levels and ADMA values during follow-up with a positive correlation in both groups and a greater reduction in the group of resistant hypertensives. We demonstrated that ADMA was an independent predictor of resistant hypertension, and we observed that the improvement in blood pressure levels obtained with the treatment was proportional to the reduction in ADMA values, suggesting a complementary role of ADMA not only as a stratification tool for the occurrence of resistant hypertension, but also as a possible therapeutic target in this population.

Nitric Oxide-cGMP Signaling in Hypertension: Current and Future Options for Pharmacotherapy

For the treatment of systemic hypertension, pharmacological intervention in nitric oxide-cyclic guanosine monophosphate signaling is a well-explored but unexploited option. In this review, we present the identified drug targets, including oxidases, mitochondria, soluble guanylyl cyclase, phosphodiesterase 1 and 5, and protein kinase G, important compounds that modulate them, and the current status of (pre)clinical development. The mode of action of these compounds is discussed, and based upon this, the clinical opportunities. We conclude that drugs that directly target the enzymes of the nitric oxide-cyclic guanosine monophosphate cascade are currently the most promising compounds, but that none of these compounds is under investigation as a treatment option for systemic hypertension.

Bariatric Surgery for Resistant Hypertension: Working in Progress!

PURPOSE OF REVIEW

To discuss the recent evidence pointing the benefits of the bariatric surgery on blood pressure control in patients with obesity and hypertension. Particular focus is devoted to discuss the potential impact on resistant hypertension.

RECENT FINDINGS

Growing evidence suggest that bariatric surgery promotes not only a significant reduction in the anti-hypertensive medication while maintained blood pressure control but also a significant proportion of hypertension remission as compared to the usual care. In a sub-analysis of the GATEWAY trial using both office and 24-h ambulatory blood pressure monitoring, the prevalence of resistant hypertension significantly decreased after 12 months in the surgical group whereas the numbers remained stable in the control group. Despite the lack of robust evidence, preliminary findings underscore the strong need to explore the potential role of bariatric surgery on resistant hypertension in patients with obesity. This statement is justified not only for the burden of obesity in this scenario but also for the unmet demands in managing resistant hypertension appropriately by multiple drug-therapy or the lack of real utility of procedures like renal denervation and carotid baroreflex activation.

Aldosterone receptor antagonists

Blocking the mineralocorticoid receptor (MR) is one of the most effective ways of reducing blood pressure in patients with resistant hypertension and improving cardiovascular prognosis in patients with heart failure with reduced ejection fraction and left ventricular dysfunction after myocardial infarction. Blockade of the biological effects of aldosterone has mostly been achieved with spironolactone and eplerenone, the two steroidal MR antagonists currently on the market. Development of new non-steroidal dihydropyridine-based third- and fourth-generation MR antagonists is ongoing. These antagonists are highly selective for the MR, but have no effect on the glucocorticoid, androgen, progesterone and estrogen receptors, in contrast with spironolactone.

Copeptin Levels in Patients With Treatment-Resistant Hypertension Before and 6 Months After Renal Denervation

BACKGROUND

Copeptin, the C-terminal peptide of provasopressin, is released from the neurohypophysis and reflects the activity of the hormone arginine vasopressin in patients with hypertension. Elevated copeptin levels are associated with increased cardiovascular and all-cause mortality. The aim of this study is to compare copeptin levels in patients with treatment-resistant hypertension (TRH) before and 6 months after renal denervation (RDN).

METHODS

Copeptin was measured in 34 patients with TRH and 30 patients with primary hypertension stage 1 or 2 (HT). In addition, copeptin levels were measured in patients with TRH at 6-month follow-up visit after RDN. RDN was performed by an experienced interventionalist applying at least 4 ablations longitudinally and rotationally within the lengths of each renal artery to cover a full 4-quadrant ablation.

RESULTS

In patients with TRH 24-hour ambulatory blood pressure (BP) decreased from 154 ± 15/87 ± 12 mm Hg to 146 ± 13/83 ± 7.9 mm Hg after RDN (systolic: P = 0.001, diastolic: P = 0.034). There was no significant change in copeptin levels in these 34 patients with TRH before vs. 6 months after RDN (median 8.4 [interquartile range 3.6-14] vs. 8.5 [4.5-13] pmol/l, P = 0.334). Patients with TRH had higher copeptin levels (P = 0.024) than patients with HT (24-hour ambulatory BP: 142 ± 11/91 ± 8.3 mm Hg, copeptin: 4.2 [2.8-6.3] pmol/l).

CONCLUSION

Patients with TRH showed 2-fold higher copeptin levels than patients with HT. RDN did not lead to any change of copeptin levels in patients with TRH 6 months after procedure despite significant fall in BP.

CLINICAL TRIAL REGISTRATION

NCT01318395, NCT01687725.

Resistant Hypertension: Novel Insights

Hypertension is the most common chronic disease and the leading risk factor for disability and premature deaths in the world, accounting for more than 9 million deaths annually. Resistant hypertension is a particularly severe form of hypertension. It was described 50 years ago and since then has been a very active field of research. This review aims at summarizing the most recent findings on resistant hypertension. The recent concepts of apparent- and true-resistant hypertension have stimulated a more precise definition of resistant hypertension taking into account not only the accuracy of blood pressure measurement and pharmacological class of prescribed drugs but also patient adherence to drugs and life-style recommendations. Recent epidemiological studies have reported a 10% prevalence of resistant hypertension among hypertensive subjects and demonstrated the high cardiovascular risk of these patients. In addition, these studies identified subgroups of patients with even higher morbidity and mortality risk, probably requiring a more aggressive medical management. In the meantime, guidelines provided more standardized clinical work-up to identify potentially reversible causes for resistant hypertension such as secondary hypertension. The debate is however still ongoing on which would be the optimal method(s) to screen for non-adherence to hypertension therapy, recognized as the major cause for (pseudo)-resistance to treatment. Recent randomized clinical trials have demonstrated the strong benefit of anti-aldosterone drugs (mostly spironolocatone) as fourth-line therapies in resistant hypertension whereas clinical trials with device-based therapies displayed contrasting results. New trials with improved devices and more carefully selected patients with resistant hypertension are ongoing.

The Potential Role of Circulating Endothelial Cells and Endothelial Progenitor Cells in the Prediction of Left Ventricular Hypertrophy in Hypertensive Patients

Background

The main aim of present study is to evaluate the potential role of circulating endothelial cells (CECs) and endothelial progenitor cells (CEPCs) – representing specific markers of endothelial damage, in the prediction of left ventricular hypertrophy (LVH) in hypertensive patients categorized into two groups; mild (MH) and resistant hypertension (RH).

Materials and Methods

Thirty patients with MH and 28 subjects with RH were involved in the study. In both groups, patients were divided into an LVH and non-LVH group. The control group included 33 age and sex-matched normotensive volunteers. Physical examination, laboratory tests and echocardiography were conducted.

Results

In both the MH and RH group, patients with as well as without LVH demonstrated a higher number of CECs and a lower ratio of CEPCs/CECs as compared to the healthy control. Multiple linear regression analysis showed a positive association of CEPCs with left ventricular mass (LVM) and left ventricular mass index (LVMI), independently of other confounders.

Conclusion

Our results suggest that endothelial injury observed as an elevated CECs number and its impaired regeneration, reflected by a lowered CEPCs/CECs ratio, precede LVH occurrence and may play a significant role in LVH development regardless of the clinical severity of hypertension. Moreover, independent correlation of CEPCs with echocardiographic (ECG) incidences of LVH suggests their potential use as a screening biomarker to stratify the risk of LVH development.

Therapeutic Drug Monitoring to Assess Drug Adherence in Assumed Resistant Hypertension: A Comparison With Directly Observed Therapy in 3 Nonadherent Patients

Resistant hypertension is a common health problem leading to suboptimal cardiovascular prevention. A large number of patients with resistant hypertension have poor medication adherence explaining their assumed resistance to therapy. We combined directly observed therapy (DOT) with therapeutic drug monitoring (TDM) in 3 patients at several time points to enable an extensive feedback on blood pressure (BP) and drug levels. BP was measured with an automatic oscillatory device at regular intervals of 5 minutes (directly before and after drug intake) and at 30-minute intervals (at night) during admission. Blood samples were obtained at different time points (t = in hours; t = 0, 2, 4, 6, 12, and 24 hours after drug intake). DOT was performed under supervision of the physician. In 2 of the 3 patients, automated BP decreased directly after DOT, -10/0 and -5/-5 mm Hg, respectively. Plasma drug levels for several drugs or active metabolites were 0 at t = 0, whereas plasma levels were positive at t = 24 hours after observed intake. We recommend a more frequent use of TDM combined with repeated BP measurements in clinical practice because this is a convenient, objective method of measurement and to ensure that actual drug levels reflect the BP at the time of measurement.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Global prevalence of resistant hypertension: a meta-analysis of data from 3.2 million patients

OBJECTIVE

We conducted the first systematic review and meta-analysis to estimate the specific prevalence of apparent treatment-resistant, pseudo-resistant and true-resistant hypertension among treated patients with hypertension globally.

METHODS

We conducted a search in PubMed, EMBASE, Web of Science and Global Index Medicus to identify articles published from inception to 30 September 2017, and searched the reference list of retrieved articles. We used a random-effects model to estimate the prevalence of resistant hypertension across studies and heterogeneity was assessed via the χ² test on Cochran's Q statistic.

RESULTS

We included 91 studies published between 1991 and 2017 reporting data of a pooled sample of 3 207 911 patients with hypertension on antihypertensive drugs globally. Most of the studies (n=64, 70%) only used office blood pressure (BP) measurement. In the general, population of treated patients with hypertension, the prevalence of true-resistant, apparent treatment-resistant and pseudo-resistant hypertension were 10.3% (95% CI 7.6% to 13.2%), 14.7% (95% CI 13.1% to 16.3%) and 10.3% (95% CI 6.0% to 15.5%). The prevalence of true-resistant hypertension was 22.9% (95% CI 19.1% to 27.0%), 56.0% (95% CI 52.7% to 59.3%) and 12.3% (95% CI 1.7% to 30.5%) in chronic kidney disease, renal transplant and elderly patients, respectively.

CONCLUSIONS

This study shows a high prevalence of true-resistant hypertension. This prevalence is lower than that of apparent treatment-resistant hypertension, demonstrating the importance to exclude causes of pseudo-resistant hypertension including white-coat hypertension with the use of ambulatory BP measurement. The burden of resistant hypertension is highest in patients with chronic kidney disease. New treatments for resistant hypertension are highly needed, considering the disastrous complications of the disease.

Copeptin is increased in resistant hypertension

OBJECTIVES

The participation of vasopressin in the mechanisms of resistant hypertension is unclear. We compared plasma copeptin concentration, a surrogate marker for vasopressin secretion, between patients with resistant hypertension and those with controlled blood pressure (CBP), in a post hoc analysis of the Prise en charge de l'Hypertension Artérielle RESistante au traitement trial.

METHODS

After 4-week treatment with irbesartan 300 mg/day, hydrochlorothiazide 12.5 mg/day, and amlodipine 5 mg/day (baseline), 166 patients were classified as having resistant hypertension (n = 140) or CBP (n = 26) by ambulatory BP monitoring. Patients with resistant hypertension were then randomized for 12 weeks of sequential nephron blockade (n = 74) or sequential renin-angiotensin system blockade (n = 66). Plasma copeptin concentration was measured at baseline and week 12 by immunoassay.

RESULTS

Baseline plasma copeptin concentration was positively associated with male sex, plasma osmolality, BP, and negatively with glomerular filtration rate. It was higher in the resistant hypertension than in the CBP group [geometric mean 5.7 (confidence interval 95% 5.1-6.4) vs. 2.9 (2.3-3.9) fmol/ml, adjusted P < 0.0001). The relationship between plasma copeptin concentration and urinary osmolality was similar in the two groups. At 12 weeks, plasma copeptin concentration in patients whose BP was controlled by sequential nephron blockade or sequential renin-angiotensin system blockade [6.8 (5.6-8.2) and 4.3 (3.0-5.9) fmol/ml, respectively) remained significantly higher than in patients with CBP at baseline (P < 0.0001 vs. both).

CONCLUSION

In patients with resistant hypertension, plasma copeptin concentrations were approximately two-fold higher than those of patients with CBP, after adjustment for plasma osmolality. This difference was not accounted for by renal resistance to vasopressin, suggesting a primary reset of osmostat.

Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation

AIMS

Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients.

METHODS AND RESULTS

A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (p<0.01 with repeated measures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04.

CONCLUSIONS

Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

MCP-1 Levels are Associated with Cardiac Remodeling but not with Resistant Hypertension

Background

Hypertension is a chronic, low-grade inflammation process associated with the release of cytokines and development of target organ damage. Deregulated monocyte chemoattractant protein-1 (MCP-1) levels have been associated with high blood pressure and cardiovascular complications; however, the mechanisms involved are complex and not fully understood.

Objective

This study aimed to compare the levels of MCP-1 in patients with resistant (RH) versus mild-to-moderate (HTN) hypertension and their association with the presence or absence of left ventricular hypertrophy (LVH) in all hypertensive subjects.

Methods

We enrolled 256 hypertensive subjects: 120 RH and 136 HTN, investigating the relationship between circulating MCP-1 levels and blood pressure, biochemical data, hematologic profile, and cardiac damage within the RH and HTN groups. Plasma MCP-1 levels were measured by ELISA and LVH was assessed by echocardiography.

Results

We found no difference in MCP-1 levels between RH and HTN subjects. On the other hand, we encountered lower MCP-1 levels in patients with LVH (105 pg/mL [100 - 260 pg/mL] versus 136 pg/mL (100 - 200 pg/mL), p = 0.005, respectively] compared with those without LVH. A logistic regression model adjusted for body mass index (BMI), age, race, aldosterone levels, and presence of diabetes and RH demonstrated that median levels of MCP-1 (2.55 pg/mL [1.22 - 5.2 pg/mL], p = 0.01) were independently associated with LVH in the entire hypertensive population.

Conclusion

Since MCP-1 levels were similar in both RH and HTN subjects and decreased in hypertensive patients with existing LVH, our study suggests a possible downregulation in MCP-1 levels in hypertensive individuals with LVH, regardless of hypertension strata.

Minoxidil for Treatment of Resistant Hypertension in Chronic Kidney Disease--A Retrospective Cohort Analysis

Resistant hypertension is still a challenge and reserve antihypertensive agents are often necessary to achieve blood pressure control. One reserve antihypertensive is minoxidil, a direct vasodilator that is known for its strong blood pressure-lowering effect, but contemporary studies are sparse. The authors retrospectively analyzed 54 inpatients with uncontrolled hypertension despite the combined use of current antihypertensive agents. To investigate the effect of minoxidil when added to other antihypertensive agents, blood pressure was evaluated at the time minoxidil treatment was initiated and at discharge. Minoxidil treatment was associated with a significant reduction in blood pressure from 162.4±15.1/83.2±12.7 mm Hg to 135.8±12.2/72.8±6.9 mm Hg (P<.0001). This effect was sustained across all analyzed subgroups. Although the well-known adverse events of minoxidil limit its widespread use, these data show that minoxidil as a reserve antihypertensive agent still has a niche indication in the particular subgroup of patients with treatment-resistant or uncontrolled hypertension.

Coronary flow reserve in patients with resistant hypertension

Resistant hypertension is associated with increased risk for cardiovascular events. Coronary flow reserve (CFR) is impaired in patients with hypertension and an independent predictor of cardiac mortality. However, there are no published data on CFR in the subset of treatment-resistant hypertension. The aim of this study was to assess CFR in patients with resistant hypertension. Twenty-five consecutive patients with primary resistant hypertension, scheduled for renal denervation, 25 matched patients with controlled hypertension, and 25 healthy controls underwent transthoracic colour Doppler echocardiography at rest and during adenosine infusion. Patients with hypertension were pair-matched with regard to age, sex, ischemic heart disease, diabetes mellitus, smoking status, and body-mass index. Healthy controls were selected according to age and sex. Mean flow velocity was measured in the left coronary anterior descending artery. Baseline mean flow velocities were similar in patients with controlled and resistant hypertension. CFR was significantly lower in patients with resistant hypertension as compared to individuals with non-resistant hypertension (2.7 ± 0.6 vs. 3.1 ± 0.8; p = 0.03). Systolic office blood pressure was significantly higher in patients with resistant hypertension (169 ± 20 vs. 144 ± 21 mm Hg; p < 0.01). Heart rate, ventricular mass, and ejection fraction were similar in the two groups. Healthy controls showed significantly lower baseline velocity, higher CFR, and lower blood pressure as compared to hypertensives. Resistant hypertension was associated with impaired CFR as compared to individuals with non-resistant hypertension indicating impaired cardiac microvascular function which may contribute to the increased risk of adverse outcome in patients with resistant hypertension.

Resistant Hypertension and the Pivotal Role for Mineralocorticoid Receptor Antagonists: A Clinical Update 2016

True resistant hypertension must be distinguished from apparent resistant hypertension, of which important causes include medication nonadherence, illicit drug use, and alcoholism. Ambulatory blood pressure monitoring should be considered to rule out white coat hypertension. The pathogenesis is multifactorial, but the 2 pivotal factors include volume excess and the myriad effects of aldosterone. Aldosterone increases vascular tone because of endothelial dysfunction and enhances the pressor response to catecholamines. It also plays a crucial role in vascular remodeling of small and large arteries. Aldosterone also promotes collagen synthesis, which leads to increased arterial stiffness and elevation of blood pressure. Because aldosterone has been demonstrated to modulate baroreflex resetting, in cases of severe hypertension, there would be fewer compensatory mechanisms available to offset the blood pressure elevation.

Interventional therapy for hypertension: Back on track again?

Treatment-resistant hypertension, or resistant hypertension, is defined as blood pressure that remains above target despite concurrent use of at least three antihypertensive agents from different classes at optimal doses, one of which should be a diuretic. Important considerations in the diagnosis of treatment-resistant hypertension include the exclusion of pseudoresistance and the evaluation of potential secondary causes of hypertension and of concomitant conditions that maintain high blood pressure. The ability to diagnose true treatment-resistant hypertension is important for selection of patients who may be appropriately treated with an invasive therapy. Currently, there are three interventional approaches to treat resistant hypertension, namely: (1) reduction of the activity of the sympathetic nervous system by renal nerve ablation, (2) stimulation of baroreceptors and (3) creation of a peripheral arterial venous anastomosis. This review focuses on the rationale behind these invasive approaches and the clinical results.

Resistant hypertension in patients with type 2 diabetes: clinical correlates and association with complications

OBJECTIVE

The phenotype of resistant hypertension in patients with type 2 diabetes has been poorly characterized. This cross-sectional analysis of the large cohort from the Renal Insufficiency and Cardiovascular Events (RIACE) study was aimed at assessing the clinical correlates and association with complications of resistant hypertension in patients with type 2 diabetes.

METHODS

The RIACE study enrolled 15,773 patients consecutively visiting 19 diabetes clinics during the years 2007-2008. Resistant hypertension, defined as BP values not on target (i.e. >130/80 mmHg, respectively) with three antihypertensive agents, was detected in 2363 individuals (15% of the whole RIACE cohort, 17.4% of hypertensive individuals, and 21.2% of treated hypertensive patients). Patients without resistant hypertension [nonresistant hypertension (NRH)], that is on target with one (n = 1569), two (n = 1369), and three (n = 803) drugs, and individuals with uncontrolled hypertension, that is untreated or not on target with less than three drugs (n = 7440), served as controls.

RESULTS

As compared with NRH and uncontrolled hypertension patients, patients with resistant hypertension were older and more frequently women and had significantly higher waist circumference, albuminuria, and serum creatinine, and lower glomerular filtration rate. Prevalence values of chronic kidney disease and advanced retinopathy were significantly higher in resistant hypertension than in both nonresistant hypertension and uncontrolled hypertension individuals, whereas cardiovascular disease was more frequent in resistant hypertension versus uncontrolled hypertension, but not nonresistant hypertension patients, especially those on 2-3 drugs.

CONCLUSIONS

Resistant hypertension is relatively common in patients with type 2 diabetes. In these individuals, age, female sex and waist circumference are independent correlates of resistant hypertension, which is strongly associated with microvascular (especially renal) disease, whereas relation with macrovascular complications is unclear.

Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a meta-analysis

OBJECTIVE

To systematically analyze the studies that have examined the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with resistant hypertension and obstructive sleep apnea (OSA).

METHODS

Design - meta-analysis of observational studies and randomized controlled trials (RCTs) indexed in PubMed and Ovid (All Journals@Ovid). participants: individuals with resistant hypertension and OSA; interventions - CPAP treatment.

RESULTS

A total of six studies met the inclusion criteria for preintervention to postintervention analyses. The pooled estimates of mean changes after CPAP treatment for the ambulatory (24-h) SBP and DBP from six studies were -7.21 mmHg [95% confidence interval (CI): -9.04 to -5.38; P < 0.001; I² 58%) and -4.99 mmHg (95% CI: -6.01 to -3.96; P < 0.001; I² 31%), respectively. The pooled estimate of the ambulatory SBP and DBP from the four RCTs showed a mean net change of -6.74 mmHg [95% CI: -9.98 to -3.49; P < 0.001; I² 61%] and -5.94 mmHg (95% CI: -9.40 to -2.47; P = 0.001; I² 76%), respectively, in favor of the CPAP group.

CONCLUSION

The pooled estimate shows a favorable reduction of BP with CPAP treatment in patients with resistant hypertension and OSA. The effects sizes are larger than those previously reported in patients with OSA without resistant hypertension.

The use of positive airway pressure therapy for treatment of resistant hypertension

It is well accepted that obstructive sleep apnea (OSA) is a risk factor for hypertension. In the subgroup of patients with resistant hypertension (rHTN), OSA appears to be particularly rampant; suggesting sleep disordered breathing may contribute to pathological mechanisms that make blood pressure difficult to control. This article explores potential mechanisms by which sleep apnea contributes to rHTN, and examines the impact of treating OSA with positive airway pressure therapy on blood pressure control. In recent years, there has been a surge of interest in randomized controlled trials of positive airway pressure therapy in patients with OSA and rHTN, because patients with rHTN respond poorly to medications. As a result, identifying novel targets for blood pressure control in this high-risk population has become paramount.

Effect and mechanism of Salicornia bigelovii Torr. plant salt on blood pressure in SD rats

In this paper, the effect and mechanism of Salicornia bigelovii Torr. plant salt (SPS) on blood pressure in Sprague Dawley (SD) rats were investigated. The results showed that the edible salt induced hypertension, but the SPS did not. Organ indices and Hematoxylin-Eosin (HE) staining analysis indicated that SPS had a protective effect on the kidney and liver. In comparison with the edible salt-treated group, nitric oxide (NO) content, angiotensin-II (Ang-II) and endothelin-1 (ET-1) levels in the serum of the SPS-treated group had no obvious changes, but serum creatinine concentration significantly decreased. Moreover, superoxide dismutase (SOD) and Na(+)-K(+)-ATPase activity increased while malondialdehyde (MDA) content decreased in the SPS-treated group. In conclusion, a long-term high salt intake could lead to hypertension. SPS, as a salt substitute, could increase the body's antioxidant ability to protect the kidney and liver from the damage caused by a high salt intake and effectively avoid the occurrence of hypertension.

Continuous Positive Airway Pressure in Patients With Obstructive Sleep Apnea and Resistant Hypertension: A Meta-Analysis of Randomized Controlled Trials

This study aimed to analyze the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with obstructive sleep apnea (OSA) and resistant hypertension. Randomized controlled trials (RCTs) that evaluated the effect of CPAP on BP in patients with OSA and resistant hypertension, indexed in MEDLINE, Embase, and the Cochrane Library from inception until March 20, 2015, were included in the meta-analysis. A total of five RCTs were identified to meet the inclusion criteria. The pooled changes after CPAP treatment for 24-hour ambulatory systolic BP and diastolic BP (DBP) were -4.78 mm Hg (95% confidence interval [CI], -7.95 to -1.61) and -2.95 mm Hg (95% CI, -5.37 to -0.53) in favor of the CPAP group. CPAP was also associated with reduction in nocturnal DBP (mean difference, -1.53 mm Hg, 95% CI, -3.07 to 0). The results indicated a favorable reduction in BP with CPAP treatment in patients with OSA and resistant hypertension.

Improving management of resistant hypertension: Rationale and protocol for a cluster randomized trial addressing physician managers in primary care

BACKGROUND

Resistant hypertension (RH) is defined as uncontrolled blood pressure (BP) despite ≥3 antihypertensive agents. It is estimated to account for 12-28% of all hypertensive patients. Despite a higher risk of cardiovascular events, hypertension therapy in these patients is often insufficient. In a previous study we successfully tested an evidence-based, physician manager-centered hypertension management.

METHODS

For this cluster randomized trial (CRT), a random sample of 102 German primary care practices will be randomized into two study arms (1:1). Physician managers and practice assistants of the intervention arm will participate in three-session medical education on hypertension management to implement 1) standardized diagnostic and therapeutic procedures for RH patients, 2) structured recall of patients with uncontrolled BP, and 3) teaching and supervision of RH patients on BP self-measurements. Practice tools are provided to facilitate implementation, e.g., how to distinguish true from pseudo RH and guideline-based medication selection. Physicians will specify guideline-algorithms for their practice to manage RH. A secured web-based peer-group exchange with hypertension specialists is offered to both professional groups. Physicians of both study arms will consecutively recruit patients with RH. BP will be measured by ambulatory BP monitoring at baseline and after 12 months. The primary endpoint is defined as treatment success with either normalized BP (24h<130/80 mmHg) and/or a reduction by ≥20 mmHg systolic and/or ≥10 mmHg diastolic. Secondary analyses will focus on changes in physicians' knowledge and practice routines.

DISCUSSION

This CRT will determine the effectiveness of a physician manager-centered intervention on treatment success in high-risk patients.

Hypertension in Chronic Kidney Disease

Hypertension, a global public health problem, is currently the leading factor in the global burden of disease. It is the major modifiable risk factor for heart disease, stroke and kidney failure. Chronic kidney disease (CKD) is both a common cause of hypertension and CKD is also a complication of uncontrolled hypertension. The interaction between hypertension and CKD is complex and increases the risk of adverse cardiovascular and cerebrovascular outcomes. This is particularly significant in the setting of resistant hypertension commonly seen in patient with CKD. The pathophysiology of CKD associated hypertension is multi-factorial with different mechanisms contributing to hypertension. These pathogenic mechanisms include sodium dysregulation, increased sympathetic nervous system and alterations in renin angiotensin aldosterone system activity. Standardized blood pressure (BP) measurement is essential in establishing the diagnosis and management of hypertension in CKD. Use of ambulatory blood pressure monitoring provides an additional assessment of diurnal variation in BP commonly seen in CKD patients. The optimal BP target in the treatment of hypertension in general and CKD population remains a matter of debate and controversial despite recent guidelines and clinical trial data. Medical therapy of patients with CKD associated hypertension can be difficult and challenging. Additional evaluation by a hypertension specialist may be required in the setting of treatment resistant hypertension by excluding pseudo-resistance and treatable secondary causes. Treatment with a combination of antihypertensive drugs, including appropriate diuretic choice, based on estimated glomerular filtration rate, is a key component of hypertension management in CKD patients. In addition to drug treatment non-pharmacological approaches including life style modification, most important of which is dietary salt restriction, should be included in the management of hypertension in CKD patients.

Ambulatory Blood Pressure Monitoring in the Diagnosis, Prognosis, and Management of Resistant Hypertension: Still a Matter of our Resistance?

Resistant hypertension, commonly described as the failure to achieve goal blood pressure (BP) despite an appropriate regimen of three antihypertensive drugs at the maximal tolerated doses, one of which is diuretic, is increasingly recognized as an important problem of public health. Large population studies with office measurements suggest that the prevalence of resistance hypertension is approximately at 6-12 % of the general hypertensive population and 8-28 % of treated hypertensives. However, these estimations do not take into account factors of pseudo-resistance, most importantly, the white-coat effect that can be effectively ruled out with ambulatory blood pressure monitoring (ABPM). Recent studies have clearly shown that when ABPM is used, at least 30-35 % of patients labeled as "resistant hypertensives" turn out to have well-controlled BP on ambulatory basis, a finding changing entirely the estimates of prevalence of resistance hypertension and actual patient handling. Furthermore, current evidence suggests that ABPM is a much more accurate predictor of cardiovascular events in resistant hypertension compared to office BP and thus can offer a better risk stratification for these high-risk individuals. Finally, ABPM offers the potential of a better evaluation of the effect of pharmacologic and non-pharmacologic therapeutic interventions. This review attempts to summarize recent evidence on the advantages of ABPM in the diagnosis, prognosis, and management of resistant hypertension.