Diagnosis and management of resistant hypertension: state of the art

Toll-like receptor 4 mutation mitigates gut microbiota-mediated hypertensive kidney injury

Hypertension-associated dysbiosis is linked to several clinical complications, including inflammation and possible kidney dysfunction. Inflammation and TLR4 activation during hypertension result from gut dysbiosis-related impairment of intestinal integrity. However, the contribution of TLR4 in kidney dysfunction during hypertension-induced gut dysbiosis is unclear. We designed this study to address this knowledge gap by utilizing TLR4 normal (TLR4N) and TLR4 mutant (TLR4M) mice. These mice were infused with high doses of Angiotensin-II for four weeks to induce hypertension. Results suggest that Ang-II significantly increased renal arterial resistive index (RI), decreased renal vascularity, and renal function (GFR) in TLR4N mice compared to TLR4M. 16 S rRNA sequencing analysis of gut microbiome revealed that Ang-II-induced hypertension resulted in alteration of Firmicutes: Bacteroidetes ratio in the gut of both TLR4N and TLR4M mice; however, it was not comparably rather differentially. Additionally, Ang-II-hypertension decreased the expression of tight junction proteins and increased gut permeability, which were more prominent in TLR4N mice than in TLR4M mice. Concomitant with gut hyperpermeability, an increased bacterial component translocation to the kidney was observed in TLR4N mice treated with Ang-II compared to TLR4N plus saline. Interestingly, microbiota translocation was mitigated in Ang-II-hypertensive TLR4M mice. Furthermore, Ang-II altered the expression of inflammatory (IL-1β, IL-6) and anti-inflammatory IL-10) markers, and extracellular matrix proteins, including MMP-2, -9, -14, and TIMP-2 in the kidney of TLR4N mice, which were blunted in TLR4M mice. Our data demonstrate that ablation of TLR4 attenuates hypertension-induced gut dysbiosis resulting in preventing gut hyperpermeability, bacterial translocation, mitigation of renal inflammation and alleviation of kidney dysfunction.

Selecting patients for interventional procedures to treat hypertension

Purpose: Interventional approaches to treat hypertension are an emerging option that may be suitable for patients whose BP control cannot be achieved with lifestyle and/or pharmacotherapy and possibly for those who do not wish to take drug therapy.Materials and Methods: Interventional strategies include renal denervation with radiofrequency, ultrasound and alcohol-mediated platforms as well as baroreflex activation therapy and cardiac neuromodulation therapy. Presently renal denervation is the most advanced of the therapeutic options and is currently being commercialised in the EU.Results: It is apparent that RDN is effective in both unmedicated patients and patients with more severe hypertension including those with resistant hypertension.Conclusion: However, at present there is no evidence for the use of RDN in patients with secondary forms of hypertension and thus evaluation to rule these out is necessary before proceeding with a procedure. Furthermore, there are numerous pitfalls in the diagnosis and management of secondary hypertension which need to be taken into consideration. Finally, prior to performing an intervention it is appropriate to document presence/absence of hypertension-mediated organ damage.

Regulatory effect of dietary nitrate on blood pressure: a meta-analysis of randomized controlled trials

Hypertension is the leading risk factor for global disease burden. Many clinical studies have reported that dietary inorganic nitrate can affect blood pressure. In this study, the PubMed, Embase, and Cochrane Library databases were searched for relevant literature published before December 2021 to explore the preventive and therapeutic effects of inorganic nitrate on hypertension. Two reviewers evaluated the randomized controlled trials of inorganic nitrates. This study included a total of 19 articles. The analyzed outcomes of the study were systolic, diastolic and mean arterial blood pressures as well as 24-hour ambulatory blood pressure. RevMan 5.4 was used to conduct meta-analysis. In the healthy population, inorganic nitrate lowered systolic blood pressure (-2.42 mmHg, 95% confidence intervals (CI) [-4.28, -0.57]; P = 0.01) but not diastolic blood pressure (-0.58 mmHg, 95% CI [-1.84, 0.68]; P = 0.36) or mean arterial pressure (-1.01 mmHg, 95% CI [-3.55, 1.54]; P = 0.44). However, in the hypertensive population, inorganic nitrates did not lower systolic blood pressure (-0.82 mmHg, 95% CI [-2.53, 0.90]; P = 0.35), diastolic blood pressure (-0.03 mmHg, 95% CI [-1.35, 1.30]; P = 0.97), 24-hour ambulatory systolic blood pressure (-0.22 mmHg, 95% CI [-1.50, 1.94]; P = 0.8), or 24-hour ambulatory diastolic blood pressure (-0.33 mmHg, 95% CI [-2.03, 1.37]; P = 0.7). In conclusion, inorganic nitrate can mildly reduce systolic blood pressure in healthy people, but does not have a lowering effect on blood pressure in patients with hypertension. Further research is required to obtain more definitive data and prove the link between inorganic nitrate and blood pressure.

Role of home blood pressure monitoring in resistant hypertension

The definition of resistant hypertension (RHT) has been updated to include failure to achieve target blood pressure (BP) despite treatment with ≥3 antihypertensive drugs, including diuretics, renin-angiotensin system blockers, and calcium channel blockers, prescribed at the maximum or maximally tolerated doses, or as success in achieving the target blood pressure but requiring ≥4 drugs. RHT is a major clinical problem, as it is associated with higher mortality and morbidity than non-RHT. Therefore, it is crucial to accurately identify RHT patients to effectively manage their disease. Out-of-clinic BP measurement, including home BP monitoring and ambulatory BP monitoring is gaining prominence for the diagnosis and management of RHT. Home BP monitoring is advantageous as it is feasibly repetitive, inexpensive, widely available, and because of its reproducibility over long periods. In addition, home BP monitoring has crucial advantage of allowing safe titration for the maximum or maximally tolerable dose, and for self-monitoring, thereby improving clinical inertia and nonadherence, and allowing true RHT to be more accurately identified.

Medication Adherence and Treatment-Resistant Hypertension in Newly Treated Hypertensive Patients in the United Arab Emirates

(1) Background: The present study aimed to analyze medication adherence and its effect on blood pressure (BP) control and assess the prevalence of treatment-resistant hypertension (TRH) among newly treated hypertensive patients in the United Arab Emirates (UAE); (2) Methods: A retrospective chart review was conducted to evaluate 5308 naïve hypertensive adults registered for the treatment across Abu Dhabi Health Services (SEHA) clinics in Abu Dhabi in 2017. After collecting data regarding basic details and BP measurements, patients were followed up for six months. Patients who did not reach BP targets despite taking three or more antihypertensive medications were defined as TRH; (3) Results: The overall adherence to antihypertensive treatment was 42%. At 6-month, a significant reduction in BP was observed in patients adherent to medications (systolic: -4.5 mm Hg and diastolic: -5.9 mm Hg) than those who were nonadherent to antihypertensive therapy (1.15 mm Hg and 3.59 mm Hg). Among 189 patients using three or more antihypertensive medications for six months, only 34% (n = 64) were adherent to the treatment, and only 13.7% (n = 26) reached the BP target. The prevalence of TRH was 20.1%; (4) Conclusions: Medication adherence and BP control among the participants were suboptimal. The study shows a high prevalence of TRH among newly treated hypertensives in the UAE. More extraordinary efforts toward improving adherence to antihypertensive therapy and more focus toward BP control and TRH are urgently needed.

Assessment of a strategy combining ambulatory blood pressure, adherence monitoring and a standardised triple therapy in resistant hypertension

PURPOSE

Poor adherence to drug therapy and inadequate drug regimens are two frequent factors responsible for the poor blood pressure (BP) control observed in patients with apparent resistant hypertension. We evaluated the efficacy of an antihypertensive management strategy combining a standardised therapy with three long acting drugs and electronic monitoring of drug adherence in patients with apparent resistant hypertension.

MATERIALS AND METHODS

In this multicentric observational study, adult patients with residual hypertension on 24 h ambulatory BP monitoring (ABMP) despite the use of three or more antihypertensive drugs could be included. Olmesartan/amlodipine (40/10 mg, single pill fixed-dose combination) and chlorthalidone (25 mg) were prescribed for 3 months in two separated electronic pills boxes (EPB). The primary outcome was 24 h ambulatory systolic BP (SBP) control at 3 months, defined as mean SBP <130 mmHg.

RESULTS

We enrolled 48 patients (36.0% women) of whom 35 had complete EPB data. After 3 months, 52.1% of patients had 24 h SBP <130 mmHg. 24 h SBP decreased by respectively -9.1 ± 15.5 mmHg, -22.8 ± 30.6 mmHg and -27.7 ± 16.6 mmHg from the tertile with the lowest adherence to the tertile with the highest adherence to the single pill combination (p = 0.024). A similar trend was observed with tertiles of adherence to chlorthalidone. Adherence superior to 90% was associated with 24 h systolic and diastolic blood pressure control in multiple logistic regression analysis (odds ratio = 14.1 (95% confidence interval 1.1-173.3, p = 0.039).

CONCLUSIONS

A simplified standardised antihypertensive therapy combined with electronic monitoring of adherence normalises SBP in about half of patients with apparent resistant hypertension. Such combined management strategy enables identifying patients who need complementary investigations and those who rather need a long-term support of their adherence.

Starting Antihypertensive Drug Treatment With Combination Therapy: Controversies in Hypertension - Con Side of the Argument

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Therapeutic Targeting of DGKA-Mediated Macropinocytosis Leads to Phospholipid Reprogramming in Tuberous Sclerosis Complex

Lymphangioleiomyomatosis is a rare destructive lung disease affecting primarily women and is the primary lung manifestation of tuberous sclerosis complex (TSC). In lymphangioleiomyomatosis, biallelic loss of TSC1/2 leads to hyperactivation of mTORC1 and inhibition of autophagy. To determine how the metabolic vulnerabilities of TSC2-deficient cells can be targeted, we performed a high-throughput screen utilizing the "Repurposing" library at the Broad Institute of MIT and Harvard (Cambridge, MA), with or without the autophagy inhibitor chloroquine. Ritanserin, an inhibitor of diacylglycerol kinase alpha (DGKA), was identified as a selective inhibitor of proliferation of Tsc2^-/- mouse embryonic fibroblasts (MEF), with no impact on Tsc2^+/+ MEFs. DGKA is a lipid kinase that metabolizes diacylglycerol to phosphatidic acid, a key component of plasma membranes. Phosphatidic acid levels were increased 5-fold in Tsc2^-/- MEFs compared with Tsc2^+/+ MEFs, and treatment of Tsc2^-/- MEFs with ritanserin led to depletion of phosphatidic acid as well as rewiring of phospholipid metabolism. Macropinocytosis is known to be upregulated in TSC2-deficient cells. Ritanserin decreased macropinocytic uptake of albumin, limited the number of lysosomes, and reduced lysosomal activity in Tsc2^-/- MEFs. In a mouse model of TSC, ritanserin treatment decreased cyst frequency and volume, and in a mouse model of lymphangioleiomyomatosis, genetic downregulation of DGKA prevented alveolar destruction and airspace enlargement. Collectively, these data indicate that DGKA supports macropinocytosis in TSC2-deficient cells to maintain phospholipid homeostasis and promote proliferation. Targeting macropinocytosis with ritanserin may represent a novel therapeutic approach for the treatment of TSC and lymphangioleiomyomatosis. SIGNIFICANCE: This study identifies macropinocytosis and phospholipid metabolism as novel mechanisms of metabolic homeostasis in mTORC1-hyperactive cells and suggest ritanserin as a novel therapeutic strategy for use in mTORC1-hyperactive tumors, including pancreatic cancer. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/2086/F1.large.jpg.

Management of resistant hypertension

PURPOSE OF REVIEW

Resistant hypertension is defined as blood pressure above patient goal despite three different antihypertensive agents at optimal dose including a diuretic. Resistant hypertension is increasingly common issue in clinical practice and it is a major risk factor of cardiovascular disease.

RECENT FINDINGS

All patients with resistant hypertension should be evaluated for possible correctable factors associated with pseudoresistance, such as poor adherence, white coat hypertension and suboptimal measurement of blood pressure. In patients with resistant hypertension, thiazide diuretics should be considered as one of the first agents, in addition to mineralocorticoids receptor antagonist.

SUMMARY

Resistant hypertension can be associated with secondary cause that is why treatment can be challenging and should always include lifestyle modification and evaluation for possible secondary causes, in addition to adding a fourth agent or considering newer interventional therapies, such as renal denervation or other device-based options.

Association of the genetic ancestry with resistant hypertension in the ReHOT (Resistant Hypertension Optimal Treatment) randomized study

Resistant hypertension (RH) is defined as uncontrolled blood pressure despite treatment with three or more antihypertensive medications, including, if tolerated, a diuretic in adequate doses. It has been widely known that race is associated with blood pressure control. However, intense debate persists as to whether this is solely explained by unadjusted socioeconomical variables or genetic variation. In this scenario, the main aim was to evaluate the association between genetic ancestry and resistant hypertension in a large sample from a multicenter trial of stage II hypertension, the ReHOT study. Samples from 1,358 patients were analyzed, of which 167 were defined as resistant hypertensive. Genetic ancestry was defined using a panel of 192 polymorphic markers. The genetic ancestry was similar in resistant (52.0% European, 36.7% African and 11.3% Amerindian) and nonresistant hypertensive patients (54.0% European, 34.4% African and 11.6% Amerindian) (p > 0.05). However, we observed a statistically suggestive association of African ancestry with resistant hypertension in brown patient group. In conclusion, increased African genetic ancestry was not associated with RH in Brazilian patients from a prospective randomized hypertension clinical trial.

Resistant Hypertension: A Clinical Perspective

Resistant hypertension is a common clinical entity, defined as suboptimal blood pressure response to multiple therapies after excluding medication nonadherence and secondary forms of hypertension. Patients with resistant hypertension generally share several comorbidities. Resistant hypertension is more common in individuals of African descent. Blood pressure should be optimized using multiple strategies, including lifestyle changes and single-pill combination therapies, with the aim of reducing cardiovascular events while reducing side effects from using antihypertensive therapy. A renin/aldosterone-based diagnostic and treatment approach will help tailor therapy. The use of mineralocorticoid receptor antagonists or amiloride as appropriate is favored.

Phase I Trial of Pyragrel, a Novel Thromboxane Synthetase Inhibitor, to Evaluate the Safety, Tolerability, and Pharmacokinetics in Healthy Volunteers

Background and Objective: Inhibition of thrombosis and platelet aggregation through a thromboxane synthetase inhibitor proved to be an effective and promising treatment for cardiovascular and/or cerebrovascular disease (CCVD) patients. This phase I study evaluated the safety, tolerability, and pharmacokinetics of sodium pyragrel, a novel thromboxane A₂ synthetase inhibitor, in healthy volunteers.

Methods: A total of 84 healthy Chinese volunteers were enrolled in the study and randomized into one of five dosing regimens of intravenous pyragrel, which were single ascending dose (30 to 300 mg), multiple doses (pyragrel 180 mg once daily on Day 1 and Day 6, twice daily from Day 2 to Day 5), 3×3 Latin square crossover (60, 120, 240 mg), and a continuous dose (360 mg in 24 h), respectively. Plasma concentrations were determined using HPLC-MS/MS. Pharmacokinetics parameters were calculated with non-compartment analysis.

Results: The maximum plasma concentrations of pyragrel were essentially reached at the end of the 3 h infusion. The pharmacokinetic process of pyragrel and two main metabolites (BBS and BJS) is linear over the 30–300 mg dose range, with no significant accumulation on multiple doses. The urinary excretion of pyragrel accounted for more than 70% of the total drug amount. Preliminary pharmacodynamic results demonstrated that the production of urinary 11-D-HTXB₂ was time- and dose-dependently inhibited by single i.v. dose of pyragrel.

Conclusions: Pyragrel was well tolerated after single ascending doses up to 300 mg, multiple doses of 180 mg, and continuous administration of 360 mg within 24 h. No drug-related, serious adverse drug reactions occurred during the five-part study. The most common pyragrel-related adverse events (AEs) were total bilirubin (TB)/direct bilirubin (DB) elevations with a relatively low incidence rate and seemed to be dose independent. Given the acceptable safety and appropriate pharmacokinetic properties of sodium pyragrel proven in this study, continued clinical development is warranted. The study was registered at http://www.chictr.org.cn (ChiCTR-IID-16010159).

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.

Resistant and refractory hypertension: two sides of the same disease?

Refractory hypertension (RfH) is an extreme phenotype of resistant hypertension (RH), being considered an uncontrolled blood pressure besides the use of 5 or more antihypertensive medications, including a long-acting thiazide diuretic and a mineralocorticoid antagonist. RH is common, with 10-20% of the general hypertensives, and its associated with renin angiotensin aldosterone system hyperactivity and excess fluid retention. RfH comprises 5-8% of the RH and seems to be influenced by increased sympathetic activity. RH patients are older and more obese than general hypertensives. It is strongly associated with diabetes, obstructive sleep apnea, and hyperaldosteronism status. RfH is more frequent in women, younger patients and Afro-americans compared to RFs. Both are associated with increased albuminuria, left ventricular hypertrophy, chronic kidney diseases, stroke, and cardiovascular diseases. The magnitude of the white-coat effect seems to be higher among RH patients. Intensification of diuretic therapy is indicated in RH, while in RfH, therapy failure imposes new treatment alternatives such as the use of sympatholytic therapies. In conclusion, both RH and RfH constitute challenges in clinical practice and should be addressed as distinct clinical entities by trained professionals who are capable to identify comorbidities and provide specific, diversified, and individualized treatment.