Adverse Health Outcomes Associated With Refractory and Treatment-Resistant Hypertension in the Chronic Renal Insufficiency Cohort

Resistant Hypertension: Disease Burden and Emerging Treatment Options

PURPOSE OF REVIEW

To define resistant hypertension (RHT), review its pathophysiology and disease burden, identify barriers to effective hypertension management, and to highlight emerging treatment options.

RECENT FINDINGS

RHT is defined as uncontrolled blood pressure (BP) ≥ 130/80 mm Hg despite concurrent prescription of ≥ 3 or ≥ 4 antihypertensive drugs in different classes or controlled BP despite prescription of  ≥ to 4 drugs, at maximally tolerated doses, including a diuretic. BP is regulated by a complex interplay between the renin-angiotensin-aldosterone system, the sympathetic nervous system, the endothelin system, natriuretic peptides, the arterial vasculature, and the immune system; disruption of any of these can increase BP. RHT is disproportionately manifest in African Americans, older patients, and those with diabetes and/or chronic kidney disease (CKD). Amongst drug-treated hypertensives, only one-quarter have been treated intensively enough (prescribed > 2 drugs) to be considered for this diagnosis. New treatment strategies aimed at novel therapeutic targets include inhibition of sodium-glucose cotransporter 2, aminopeptidase A, aldosterone synthesis, phosphodiesterase 5, xanthine oxidase, and dopamine beta-hydroxylase, as well as soluble guanylate cyclase stimulation, nonsteroidal mineralocorticoid receptor antagonism, and dual endothelin receptor antagonism. The burden of RHT remains high. Better use of currently approved therapies and integrating emerging therapies are welcome additions to the therapeutic armamentarium for addressing needs in high-risk aTRH patients.

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.

Prevalence, Predictors, and Outcomes of Resistant Hypertension in Egyptian Population

Background

Hypertension is a leading problem; it affects around thirty million adult Egyptians, according to the last national registry. The exact prevalence of resistant hypertension (RH) in Egypt wasn't spotted before. The purpose of this study was to determine the prevalence, predictors, and impact on adverse cardiovascular outcomes among adult Egyptians with RH.

Methods

The present study examined a cohort of 990 hypertensive patients who were divided into two groups based on their blood pressure control; group I (n = 842) patients who achieved blood pressure control and group II (n = 148) patients who met the RH definition criteria. All patients underwent a close follow-up for one year to evaluate the major cardiovascular events.

Results

The prevalence of RH was 14.9%. The main predictors impacting the cardiovascular outcomes of RH were advanced age (≥65 years), the presence of chronic kidney diseases, a BMI ≥ 30 kg/m², and NSAID use. After one year of follow-up, the RH group displayed noticeably higher rates of major cardiovascular events, including new-onset atrial fibrillation (6.8% vs. 2.5%, P = 0.006), cerebral stroke (4.1% vs. 1.2%, P = 0.011), myocardial infarction (4.7% vs. 1.3%, P = 0.004), and acute heart failure (4.7% vs. 1.8%, P = 0.025).

Conclusion

The prevalence of RH in Egypt is moderately high. Patients with RH have a far higher risk of cardiovascular events than those whose blood pressure is within control.

The renal artery-aorta angle associated with renal artery plaque: a retrospective analysis based on CT

PURPOSE

To investigate the relationship between renal artery anatomical configuration and renal artery plaque (RAP) based on 320-row CT.

METHODS

The abdominal contrast-enhanced CT data from 210 patients was retrospectively analyzed. Among 210 patients, there were 118 patients with RAP and 92 patients with no RAP. The anatomical parameters between lesion group and control group were compared and analyzed by using t-test, χ2-test and logistic regression analysis.

RESULTS

(1) There were statistical differences on age, hypertension, diabetes, hypertriglyceridemia and hypercholesterolemia between lesion group and control group. (2) The differences on the distribution and type and of RAP between lesion group and control group were statistically significant. The most common position was the proximal, and the most common type was calcified plaque. (3)There were significant statistical differences on the proximal diameter of renal artery and renal artery-aorta angle A between lesion group and control group. The differences on the other anatomical factors between two groups were not statistically significant. (4) The result of logistic regression analysis showed that right RAP was related to age, hypertension and right renal artery angle A (the AUC of ROC = 0.82), and left RAP was related to high serum cholesterol, age and left renal artery angle A(the AUC of ROC = 0.83). (5) The RAP was associated with renal artery-aorta angle A, but the differences on distribution, type stability of RAP between R1 (L1) group and R2 (L2) group were not statistically significant.

CONCLUSIONS

The RAP was associated with age, hypertension, hypercholesterolemia and renal artery-aorta angle A. Adults which had the greater renal artery-aorta angle A and the other above risk factors may be at increased risk for RAP.

A systems biology approach identifies the role of dysregulated PRDM6 in the development of hypertension

Genetic variants in the third intron of the PRDM6 gene have been associated with BP traits in multiple GWAS. By combining fine mapping, massively parallel reporter assays, and gene editing, we identified super enhancers that drive the expression of PRDM6 and are partly regulated by STAT1 as the causal variants for hypertension. The heterozygous disruption of Prdm6 in mice expressing Cre recombinase under the control of mouse smooth muscle cell protein 22-α promoter (Prdm6fl/+ SM22-Cre) exhibited a markedly higher number of renin-producing cells in the kidneys at E18.5 compared with WT littermates and developed salt-induced systemic hypertension that was completely responsive to the renin inhibitor aliskiren. Strikingly, RNA-Seq analysis of the mouse aortas identified a network of PRDM6-regulated genes that are located in GWAS-associated loci for blood pressure, most notably Sox6, which modulates renin expression in the kidney. Accordingly, the smooth muscle cell-specific disruption of Sox6 in Prdm6fl/+ SM22-Cre mice resulted in a dramatic reduction of renin. Fate mapping and histological studies also showed increased numbers of neural crest-derived cells accompanied by increased collagen deposition in the kidneys of Prdm6fl/+ Wnt1Cre-ZsGreen1Cre mice compared with WT mice. These findings establish the role of PRDM6 as a regulator of renin-producing cell differentiation into smooth muscle cells and as an attractive target for the development of antihypertensive drugs.

An Update on Refractory Hypertension

Purpose of Review

To update on definition, diagnosis, prevalence, patient characteristics, pathophysiology, and treatment of refractory hypertension (RfHTN).

Recent Findings

Refractory hypertension (RfHTN) is defined as blood pressure (BP) that is uncontrolled despite using ≥ 5 antihypertensive medications of different classes, including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist (MRA) at maximal or maximally tolerated doses. This new phenotype is different from resistant hypertension (RHTN), defined as BP that is uncontrolled despite using ≥ 3 medications, commonly a long-acting calcium channel blocker (CCB), a blocker of the renin-angiotensin system (angiotensin-converting enzyme [ACE] inhibitor or angiotensin receptor blocker [ARB]), and a diuretic. The RHTN phenotype includes controlled RHTN, BP that is controlled on 4 or more medications. RfHTN is largely attributable to increased sympathetic activity, unlike RHTN, which is mainly due to increased intravascular fluid volume frequently caused by hyperaldosteronism and chronic excessive sodium ingestion. Compared to those with controlled RHTN, patients with RfHTN have a higher prevalence of target organ damage and do not have elevated aldosterone levels. Ongoing clinical trials are assessing the safety and efficacy of using devices to aid with BP control in patients with RfHTN.

Summary

RfHTN is a separate entity from RHTN and is generally attributable to increased sympathetic activity.

Clinical Effect of Mudan Granule on Peripheral Neuritis Caused by Chronic Renal Insufficiency

Objective

To investigate the clinical effect of Mudan granule on peripheral neuritis caused by chronic renal insufficiency (CRI).

Methods

Sixty patients with peripheral neuritis caused by CRI treated in our hospital were included from February 2018 to April 2021 in this study. The patients were arbitrarily assigned into control group and study group. The former accepted routine treatment, while the latter accepted Mudan granule treatment. The clinical efficacy, traditional Chinese medicine (TCM) clinical symptom score, nerve conduction velocity, hemorheology index, renal function index, and inflammatory factor index were compared.

Results

We firstly compared the clinical efficacy: the study group was clinically cured in 22 cases, obviously effective in 5 cases, effective in 3 cases, and ineffective in 1 case, with a total effective rate of 96.67%. The control group was clinically cured in 9 cases, obviously effective in 8 cases, effective in 7 cases, and ineffective in 6 cases, with a total effective rate of 80.00%. The total effective rate of the study group was higher compared to the control group (P < 0.05). Secondly, we compared the TCM clinical symptom scores; before treatment, there exhibited no significant difference (P > 0.05); after treatment, the TCM clinical symptom scores decreased. The clinical symptom score of TCM in the study group was lower compared to the control group (P < 0.05). Compared with the control group, the nerve conduction velocity of left MCV, right MCV, left SCV, and right SCV in the study group were remarkably higher. In terms of the hemorheological indexes, the high-shear whole blood viscosity, low-shear whole blood viscosity, and plasma viscosity in the study group were lower compared with the control group (P < 0.05). Before treatment, there existed no significant difference in renal function indexes, but after treatment, the renal function indexes decreased, and the levels of serum creatinine (SCr), blood urea nitrogen (BUN), and uric acid (UA) in the study group were lower compared to the control group (P < 0.05). Finally, we compared the indexes of inflammatory factors; there existed no significant difference before treatment, but after treatment, the indexes of inflammatory factors decreased in both groups, and the levels of IL-6 and CRP in the study group were lower compared to the control group (P < 0.05).

Conclusion

For peripheral neuritis caused by CRI, Mudan granule can remarkably promote the clinical symptoms of TCM and reduce the syndrome score of TCM; moreover, it can remarkably increase the nerve conduction velocity of median nerve and common peroneal nerve and reduce blood viscosity, which is worth popularizing and developing in clinic.

Refractory Hypertension: a Narrative Systematic Review with Emphasis on Prognosis

PURPOSE OF REVIEW

To perform a narrative systematic review on refractory hypertension (RfHT) with particular emphasis on prognosis.

RECENT FINDINGS

There were 37 articles on RfHT, 13 non-systematic reviews, and 24 original studies. RfHT, a recently described extreme phenotype of anti-hypertensive treatment failure, shall be defined as uncontrolled out-of-office blood pressure (BP) levels despite the use of at least 5 anti-hypertensive drugs, including a long-acting diuretic and a mineraloreceptor antagonist. Its prevalence ranges from 0.5 to 4.3% of general treated hypertensives and between 3.6 and 51.4% of patients with resistant hypertension (RHT). RfHT is associated with younger age, African ancestry, obesity, hypertension-mediated organ damage and clinical cardiovascular diseases, and with some comorbidities, such as diabetes and obstructive sleep apnea. Its physiopathological mechanisms probably involve sympathetic overactivity and not volume overload. Patients with RfHT have a worse prognosis than non-refractory RHT individuals, with higher risks of adverse cardiovascular and renal outcomes and of mortality. RfHT represents a rare but true extreme phenotype of anti-hypertensive treatment failure distinct from RHT and with a significantly worse prognosis. Identifying such individuals is important to tailor specific interventions.

Pathophysiologically based antihypertensive pharmacotherapeutics rationality, efficacy and safety in Sub Saharan African Nations – A review

Background

Hypertension (HT) prevalence, Uncontrolled Blood Pressure (UBP), morbidity and mortality are highest in Sub-Saharan Africa (SSA). Correlating pathophysiology of HT to pharmaco-therapy with antihypertensive drugs (AHD) may bring amelioration. Aims:To review peculiarities of HT in SSA, UBP causes, diagnostic modalities, AHD use, rationality and efficacy.

Methods and results

14 published therapeutic audits in 4 SSA nations on Google Scholar or PUBMED, (total n = 6496 patients) were evaluated. Calcium Channel blockers (CCB) amlodipine, and thiazide diuretics (TD), hydrochlorothiazide (HCTZ) were the commonest AHD. Thiazide Like Diuretics (TLD) were underutilized. The % of patients on AHD were: 1 drug 5.4–55%; 2 drugs 37–82%; >/ = 3 drugs 6–50.3%. 2-drug combinations were: ACEI/ARB + TD (42%); CCB + TD (36.8%); ACEI + CCB (15.8%) of studies. Triple/quadruple therapy included Methyldopa (MTD) with ACEI + CCB or TD. The (%) attaining BP < 140/< 90 mmHg, ranged from 29 to 53.6%, median, 44%. The co-morbidities, range and median were: Diabetes Mellitus (DM): 9.8–64%, 19.2%; Chronic Kidney Disease (CKD): 5.7–7.5%, 6.9%, and Coronary artery Disease (CAD): 0.9–2.6%, 2.3%. ACEI + CCB ± TD were the preferred AHD for comorbidities.

Conclusions

Therapeutic inertia; Non-compliance; co-morbidities; refractory HT; ignorance; substandard AHD; contribute to UBP. Studies relating 24 hour ABPM to complications and mortality in SSA hypertensives; and impact of different AHD classes on ABPM, are needed. Study of ACEI + alpha-₁ blockers + TLD on 24 hour ABPM and personalized care, are required.