Resistant or Difficult‐to‐Treat Hypertension

Machine learning approach to predict subtypes of primary aldosteronism is helpful to estimate indication of adrenal vein sampling

INTRODUCTION

Primary aldosteronism (PA) is a common disease. Especially in unilateral PA (UPA), the risk of cardiovascular disease is high and proper localization is important. Adrenal vein sampling (AVS) is commonly used to localize PA, but its availability is limited. Therefore, it is important to predict the unilateral or bilateral PA and to choose the appropriate cases for AVS or watchful observation.

AIM

The purpose of this study is to develop a model using machine learning to predict bilateral or unilateral PA to extract cases for AVS or watchful observation.

METHODS

We retrospectively analyzed 154 patients diagnosed with PA and who underwent AVS at our hospital between January 2010 and June 2021. Based on machine learning, we determined predictors of PA subtypes diagnosis from the results of blood and loading tests.

RESULTS

The accuracy of the machine learning was 88% and the top predictors of the UPA were plasma aldosterone concentration after the saline infusion test, aldosterone to renin ratio after the captopril challenge test, serum potassium and aldosterone-to-renin ratio. By using these factors, the accuracy, sensitivity, specificity and the area under the curve (AUC) were 91%, 70%, 99% and 0.91, respectively. Furthermore, we examined the surgical outcomes of UPA and found that the group diagnosed as unilateral by the predictors showed improvement in clinical findings, while the group diagnosed as bilateral by the predictors showed no improvement.

CONCLUSION

Our predictive model based on machine learning can support to choose the performance of adrenal vein sampling or watchful observation.

Percutaneous transluminal renal angioplasty of global kidney ischemia improves renal function and blood pressure

Background

Renal artery stenosis (RAS) can lead to hypertension and renal failure. Nevertheless, its treatment by percutaneous transluminal renal angioplasty (PTRA) remains controversial. It is unknown, whether patients with global kidney ischemia (GKI), that means patients with bilateral RAS or RAS with a single functioning kidney, may benefit from PTRA or not.

Methods

We retrospectively analyzed 93 patients with RAS (25 bilateral or single functioning kidney) undergoing PTRA. Patients had refractory hypertension (≥3 medications). Blood pressure, antihypertensive drugs and serum-creatinine were compared pre-/post-intervention and at 1 year’s follow-up.

Results

At 1 year after PTRA of patients with GKI, systolic and diastolic blood pressure were significantly reduced compared to patients with unilateral PTRA (systolic: −19.1 ± 10.5 [bilateral] vs. −11.4 ± 12.1 mmHg [unilateral], P < 0.01; diastolic: −10.1 ± 6.8 mmHg vs. −6.3 ± 6.6 mmHg, P < 0.05). The number of antihypertensive drugs was reduced by −0.8 ± 3.0 at 1 year in patients with GKI, while it increased by +0.1 ± 3.5 in the unilateral RAS group (P < 0.001). Furthermore, post-interventional serum-creatinine decreased by −34.6 ± 31.4 μmol/I after of patients with GKI (P < 0.001 vs. baseline). In patients with unilateral PTRA, a non-significant increase in serum-creatinine was observed (+8.3 ± 2 μmol/l).

Conclusion

PTRA in patients with GKI led to improved blood pressure and renal function. A large, well-designed, randomized clinical trial targeting this population is still needed. The benefit of PTRA should be measured with the risks in each patient individually.

Antihypertensive Treatment Patterns and Blood Pressure Control in Older Adults: Results from the Berlin Aging Study II

BACKGROUND

Hypertension is highly prevalent in older adults and represents a major public health issue since recognition, awareness, treatment and control are insufficient. Analyses of prescription patterns in conjunction with clinical parameters can provide novel insights into the current practice of hypertension management and help to identify barriers to sufficient hypertension control.

METHODS

A cross-sectional analysis was conducted. Prevalence of hypertension, patterns of antihypertensive therapy, and determinants of blood pressure (BP) control were examined in the Berlin Aging Study II cohort, including 1654 community-dwelling older adults (60-85 years of age).

RESULTS

Of the participants, 75.9% had hypertension; 40.6% of these were not prescribed BP medications. Lack of hypertension awareness, younger age, absence of comorbidities, not being on a statin, and not having visited a physician in the past 3 months were associated with lack of treatment. Forty-two percent of treated hypertensive individuals received monotherapy and 58.0% received combination therapy. Renin-angiotensin-aldosterone system (RAAS) inhibitors, and β-blockers were most commonly prescribed, while calcium channel blockers were least prescribed. Only 38.5% of treated hypertensive individuals had their BP controlled to < 140/90 mmHg. Number and choice of BP medications were not predictive of BP control; neither were age, glycated hemoglobin (HbA_1c), kidney function, or number of healthcare visits. However, female sex, lower low-density lipoprotein cholesterol (LDL-C) levels and current smoking, amongst others, were positively associated with BP control. There was evidence of significant effect modification by statins in the association of LDL-C and BP.

CONCLUSION

The majority of older adults do not reach BP goals. Antihypertensive prescription patterns do not conform to current guidelines. Using more BP medications was not associated with higher odds of BP control. Lowering LDL-C might be favorable in terms of BP control.

Aliskiren for Renin Inhibition: A New Class of Antihypertensives

Objective:

To review the safety, efficacy, pharmacology, pharmacokinetics, and drug interactions of aliskiren for the treatment of mild-to-moderate hypertension.

Data Sources:

A literature search was conducted using MEDLINE (1966'January 2007), International Pharmaceutical Abstracts (1970'January 2007), and Cochrane database (2006) for the key words aliskiren or SPP100. References of selected articles were also reviewed. Abstract data were included only in the absence of significant published data.

Study Selection And Data Extraction:

Available English-language data from reviews, abstracts, and clinical trials were selected. For review of efficacy, randomized controlled trials were preferred.

Data Synthesis:

Aliskiren is a renin inhibitor, the first in a new class of antihypertensives. As renin catalyzes the rate-limiting step of the renin–angiotensin system (RAS), renin inhibition may offer a theoretical advantage over other RAS inhibitors, such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). In short-term clinical trials (≤8 wk) of subjects with mild-to-moderate hypertension, single daily doses of aliskiren 150–300 mg produced significant systolic and diastolic blood pressure reduction similar to that achieved with ACE inhibitors and ARBs, with placebo-like tolerability, without an elevation in heart rate or evidence of tolerance.

Conclusions:

Aliskiren appears to be a safe and effective treatment option in mild-to-moderate hypertension. Although long-term outcome data have not been published, aliskiren is a promising option for RAS inhibition.

Nebivolol monotherapy for patients with systolic stage II hypertension: results of a randomized, placebo-controlled trial

BACKGROUND

Elevated systolic blood pressure (SBP) is an independent risk factor for cardiovascular events and mortality.

OBJECTIVE

The goal of this study was to assess whether nebivolol (NEB), a vasodilatory β(1)-selective blocker, is a safe and efficacious monotherapy for individuals with systolic stage II hypertension.

METHODS

In this multicenter trial, 18- to 64-year-olds who had not used antihypertensive treatment for at least 4 weeks and had SBP/diastolic blood pressure (DBP) of 160 to 180/90 to 110 mm Hg were randomized to receive double-blind medication for 6 weeks (NEB, n = 290; placebo [PBO], n = 142). Depending on response, the starting dose (5 mg/d) could be increased directly to 20 mg/d. Primary parameters were baseline-end point changes in trough seated SBP and DBP (intent-to-treat [ITT] population); the Hochberg method was used to control the type I error (α = 0.05). Responder analysis was also performed. Safety and tolerability assessment included monitoring of adverse events (AEs).

RESULTS

Mean age at baseline (ITT) was 50.7 years, and the mean SBP/DBP values were 167/101 mm Hg; 202 (47.3%) participants were women, 276 (63.9%) had body mass index ≥30 kg/m(2), 152 (35.2%) were black, and 161 (37.3%) were Hispanic. Completion rates were 79.7% (PBO) and 90.3% (NEB). After 2 weeks of treatment, 92% and 95% participants in the NEB and PBO groups, respectively, had SBP in the range of 130 to 180 mm Hg and were titrated to the 20-mg/d NEB dose or its matching PBO tablet. After 6 weeks of treatment, the NEB group experienced significant mean reductions compared with the PBO group for both SBP (-18.2 vs -12.3 mm Hg; P < 0.001) and DBP (-12.3 vs -5.7 mm Hg; P < 0.001), down to mean SBP/DBP values of 149/89 mm Hg and 155/95 mm Hg, respectively, and had a significantly higher percentage of individuals who achieved BP control (SBP/DBP <140/90 mm Hg, 30.6% vs 17.3%; P = 0.004). Post hoc analyses suggest that NEB was not efficacious in reducing SBP in black participants. Mean changes in pulse rate were -12.8 beats/min for the NEB group and -1.6 beats/min for the PBO group (P < 0.001). Rates of discontinuations due to an AE (NEB vs PBO) were 1.4% in both groups, rates of any treatment-emergent AEs were 19.7% versus 19.0%, and rates of serious AEs were 0.3% versus 2.1%. The most common AEs (NEB vs PBO) were headache (2.1% vs 2.8%) and hypertension (0.7% vs 2.1%).

CONCLUSIONS

NEB monotherapy was an efficacious and well-tolerated treatment option for these study individuals with systolic stage II hypertension, but most of them would need combination therapy to achieve BP control.

Diagnostics of primary aldosteronism: is obligatory use of confirmatory tests justified?

Introduction:

Assessment of the renin-angiotensin-aldosterone system has been recently granted a much greater role in the evaluation of patients with arterial hypertension. There is no single test efficient in selection of patients for second-step etiological investigation.

Methods:

Altogether, 198 consecutive patients − 119 women (60%) and 79 men (40%) – hospitalized in years 2009–2011 at the Clinical Department of Endocrinology Medical University of Bialystok were diagnosed with primary aldosteronism. In each patient, plasma renin activity and plasma aldosterone concentration (basic and after 2 l NaCl infusion) were evaluated.

Results:

The percentage of patients with plasma aldosterone concentration ≥15 ng/ml was 53 and the percentage of patients with plasma renin activity ≤0.1 ng/ml/h was 20. The percentage of patients screened for primary aldosteronism in which the aldosterone:renin ratio exceeded consecutive cut-offs of 20, 30, 40 and 50 were respectively 57, 45, 34 and 29. Among 15 patients in which plasma aldosterone concentration after infusion of 2 l of saline was ≥6.5 ng/dl (8.6%), 13 (6.6%) were diagnosed with primary aldosteronism.

Conclusion:

The obligatory use of tests confirming autonomy of aldosterone secretion in patients screened for primary aldosteronism seems cost-effective in limiting the number of patients for further diagnosis.

Resistant hypertension workup and approach to treatment

Resistant hypertension is defined as blood pressure above the patient's goal despite the use of 3 or more antihypertensive agents from different classes at optimal doses, one of which should ideally be a diuretic. Evaluation of patients with resistive hypertension should first confirm that they have true resistant hypertension by ruling out or correcting factors associated with pseudoresistance such as white coat hypertension, suboptimal blood pressure measurement technique, poor adherence to prescribed medication, suboptimal dosing of antihypertensive agents or inappropriate combinations, the white coat effect, and clinical inertia. Management includes lifestyle and dietary modification, elimination of medications contributing to resistance, and evaluation of potential secondary causes of hypertension. Pharmacological treatment should be tailored to the patient's profile and focus on the causative pathway of resistance. Patients with uncontrolled hypertension despite receiving an optimal therapy are candidates for newer interventional therapies such as carotid baroreceptor stimulation and renal denervation.

Combination therapy in hypertension

The goal of antihypertensive therapy is to abolish the risks associated with blood pressure (BP) elevation without adversely affecting quality of life. Drug selection is based on efficacy in lowering BP and in reducing cardiovascular (CV) end points, including stroke, myocardial infarction, and heart failure. Although the choice of initial drug therapy exerts some effect on long-term outcomes, it is evident that BP reduction per se is the primary determinant of CV risk reduction. Available data suggest that at least 75% of patients will require combination therapy to achieve contemporary BP targets, and increasing emphasis is being placed on the practical tasks involved in consistently achieving and maintaining goal BP in clinical practice. It is within this context that the American Society of Hypertension presents this Position Paper on Combination Therapy for Hypertension. It will address the scientific basis of combination therapy, present the pharmacologic rationale for choosing specific drug combinations, and review patient selection criteria for initial and secondary use. The advantages and disadvantages of single-pill (fixed) drug combinations and the implications of recent clinical trials involving specific combination strategies will also be discussed.

Combination therapy in hypertension

The goal of antihypertensive therapy is to abolish the risks associated with blood pressure (BP) elevation without adversely affecting quality of life. Drug selection is based on efficacy in lowering BP and in reducing cardiovascular (CV) end points including stroke, myocardial infarction, and heart failure. Although the choice of initial drug therapy exerts some effect on long-term outcomes, it is evident that BP reduction per se is the primary determinant of CV risk reduction. Available data suggest that at least 75% of patients will require combination therapy to achieve contemporary BP targets, and increasing emphasis is being placed on the practical tasks involved in consistently achieving and maintaining goal BP in clinical practice. It is within this context that the American Society of Hypertension presents this Position Paper on Combination Therapy for Hypertension. It will address the scientific basis of combination therapy, present the pharmacologic rationale for choosing specific drug combinations, and review patient selection criteria for initial and secondary use. The advantages and disadvantages of single pill (fixed) drug combinations, and the implications of recent clinical trials involving specific combination strategies will also be discussed.

Circulating endothelial progenitor cells, Th1/Th2/Th17-related cytokines, and endothelial dysfunction in resistant hypertension

INTRODUCTION

A possible link between chronic vascular inflammation and arterial hypertension is now an object of intensive studies.

OBJECTIVE

To compare Th1/Th2/Th17 cells-related cytokines, circulating endothelial progenitor cells (EPC), and endothelial function in subjects with resistant arterial hypertension (RAH) and controlled arterial hypertension (CAH).

METHODS

Blood pressure was measured by electronic sphygmomanometer. EPC were identified as CD34+/CD133+/kinase insert domain receptor (KDR)+ cells by flow cytometry. Th1/Th2/Th17 cells-related cytokines were identified using the Human Th1/Th2/Th17 Cytokines MultiAnalyte ELISArray Kit. Endothelium-dependent (FMD) vasodilatation of brachial artery was measured by Doppler ultrasound scanning.

RESULTS

RAH group (n = 20) and CAH group (n = 20) and 17 healthy individuals (control group) were recruited. In the RAH group, lower blood levels of EPC number (42.4 +/- 16.7 cells/mL) and EPC% (0.19 +/- 0.08%) were observed than in the CAH group (93.1 +/- 88.7 cells/mL; P = 0.017; 0.27 +/- 0.17; P = 0.036) and control group (68.5 +/- 63.6 cells/mL; P < 0.001; 0.28 +/- 0.17%; P = 0.003), respectively. Plasma transforming growth factor-beta1 levels were significantly higher in the RAH group (1767 +/- 364 pg/mL) than in the CAH group (1292 +/- 349; P < 0.001) and in control group (1203 +/- 419 pg/mL; P < 0.001). In the RAH group, statistically significant negative correlation was observed between systolic blood pressure and EPC% (r = -0.72, P < 0.01). FMD in the RAH group was significantly lower (5.5 +/- 0.8%) than in the CAH group (9.2 +/- 1.4; P < 0.001) and in healthy controls (10.1 +/- 1.1%; P < 0.001).

CONCLUSION

RAH is characterized by reduced circulating EPC, substantial endothelial dysfunction, and increased plasma transforming growth factor-beta1 levels.

Clinical approach in treatment of resistant hypertension

Resistant hypertension, defined as failure to achieve target blood pressure despite the use of optimal or maximum doses of at least 3 agents, one of which is a diuretic, or requiring 4 or more medications to achieve blood pressure goal, is likely to affect up to 20% of all patients with hypertension. Apparent resistant hypertension may be caused by medication nonadherence, substances that either interfere with antihypertensive mediations or cause blood pressure elevation, and under- or inappropriate medication treatment. Certain patient characteristics are associated with the presence of resistant hypertension and include chronic kidney disease, diabetes, obesity, and presence of end-organ damage (microalbuminuria, retinopathy, left-ventricular hypertrophy). Secondary causes of resistant hypertension are not uncommon and include obstructive sleep apnea, chronic kidney disease, primary aldosteronism, renal artery stenosis, pheochromocytoma, and Cushing's disease. Initial medication management usually includes adding or increasing the dose of a diuretic, which is effective in lowering the blood pressure of a large number of patients with resistant hypertension. Additional management options include maximizing lifestyle modification, combination therapy of antihypertensive agents depending on individual patient characteristics, adding less-commonly used fourth- or fifth-line antihypertensive agents, and referral to a hypertension specialist.

The top 10 things nephrologists wish every primary care physician knew

Renal disease is commonly encountered by primary care physicians during their day-to-day visits with patients. Common renal disorders include hypertension, proteinuria, kidney stones, and chronic kidney disease. Despite their prevalence, many physicians may be unfamiliar with the diagnosis and initial treatment of these common renal disorders. Early recognition and intervention are important in slowing the progression of chronic kidney disease and preventing its complications. The evidence-based pearls in this article will help primary care physicians avoid common pitfalls in the recognition and treatment of such disorders and guide their decision to refer their patients to a specialist.

The top 10 things nephrologists wish every primary care physician knew

Renal disease is commonly encountered by primary care physicians during their day-to-day visits with patients. Common renal disorders include hypertension, proteinuria, kidney stones, and chronic kidney disease. Despite their prevalence, many physicians may be unfamiliar with the diagnosis and initial treatment of these common renal disorders. Early recognition and intervention are important in slowing the progression of chronic kidney disease and preventing its complications. The evidence-based pearls in this article will help primary care physicians avoid common pitfalls in the recognition and treatment of such disorders and guide their decision to refer their patients to a specialist.

Resistant hypertension: an overview of evaluation and treatment

Resistant hypertension is defined as failure to achieve goal blood pressure (BP) when a patient adheres to the maximum tolerated doses of 3 antihypertensive drugs including a diuretic. Although the exact prevalence of resistant hypertension is currently unknown, indirect evidence from population studies and clinical trials suggests that it is a relatively common clinical problem. The prevalence of resistant hypertension is projected to increase, owing to the aging population and increasing trends in obesity, sleep apnea, and chronic kidney disease. Management of resistant hypertension must begin with a careful evaluation of the patient to confirm the diagnosis and exclude factors associated with "pseudo-resistance," such as improper BP measurement technique, the white-coat effect, and poor patient adherence to life-style and/or antihypertensive medications. Education and reinforcement of life-style issues that affect BP, such as sodium restriction, reduction of alcohol intake, and weight loss if obese, are critical in treating resistant hypertension. Exclusion of preparations that contribute to true BP treatment resistance, such as nonsteroidal anti-inflammatory agents, cold preparations, and certain herbs, is also important. Lastly, BP control can only be achieved if an antihypertensive treatment regimen is used that focuses on the genesis of the hypertension. An example is volume overload, a common but unappreciated cause of treatment resistance. Use of the appropriate dose and type of diuretic provides a solution to overcome treatment resistance in this instance.

Effectiveness of the selective aldosterone blocker, eplerenone, in patients with resistant hypertension

Resistant hypertension is defined as uncontrolled hypertension despite intensive treatment with at least three antihypertensive agents, one of which ideally should be a diuretic. To determine the efficacy and safety of the selective aldosterone antagonist eplerenone in this population, we studied patients with resistant hypertension (clinic blood pressure [BP] >140 mm Hg systolic or >90 mm Hg diastolic on maximal doses of more than three antihypertensive agents, including a loop or thiazide diuretic). At baseline and after 12 weeks of eplerenone therapy (50 to 100 mg daily titrated to effect), patients underwent clinic and 24-hour BP measurements, serum potassium, plasma renin activity, and serum aldosterone measurements. Patients (n = 52) completing the trial averaged 62 +/- 10 years of age, were overweight (mean body mass index, 32.1 +/- 5.5 kg/m(2)), and had variable renal function (glomerular filtration rate, 106 +/- 38 mL/minute); 70% were men and 74% were non-Black. The mean number of antihypertensive agents at baseline was 3.7 +/- 0.8 (range, three to seven drugs) to achieve a clinic BP of 150.5/84.1 mm Hg. The mean serum aldosterone was 12.9 +/- 7.6 ng/mL and plasma renin activity was 2.3 +/- 2.7 ng/mL/hour. After eplerenone, the change from baseline in the clinic BP was -17.6/-7.9 mm Hg (P < .0001 for both systolic blood pressure [SBP] and diastolic blood pressure [DBP]) and in 24-hour BP was -12.2/-6.0 mm Hg (P < .0001 for both). The number of antihypertensive drugs decreased to 3.3 +/- 0.9 (range, one to seven agents). Plasma potassium increased by 0.30 +/- 0.45 mEq/L (P < .001), but there were only three instances in two patients of mild hyperkalemia (potassium >5.5 mEq/L, but <6.0 mEq/L), despite all patients being on a background therapy that included an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Reductions in clinic and ambulatory BP were related to baseline clinic and ambulatory BP values (r(2) > 0.3 for both SBP and DBP, P < .0001), weakly related to baseline serum aldosterone (r = -0.30; P = .05), and unrelated to plasma renin activity, age, gender, or race. In conclusion, eplerenone demonstrated substantial efficacy in treatment-resistant hypertension and was well-tolerated with modest changes in plasma potassium. Serum aldosterone and plasma renin activity did not predict BP responses to eplerenone in this population.

Renin inhibition with aliskiren

1. Initial attempts to inhibit renin in humans have faced numerous difficulties. Molecular modelling and X-ray crystallography of the active site of renin have led to the development of new orally active renin inhibitors, such as aliskiren. 2. Aliskiren has a low bioavailability (between 2.6 and 5.0%) compensated by its high potency to inhibit renin (IC50: 0.6 nmol/L) and a long plasma half-life (23-36 h), which makes it suitable for once-daily dosing. 3. The once-daily administration of aliskiren to hypertensive patients lowers BP as strongly as standard doses of established angiotensin II type 1 (AT1) receptor blockers (losartan, valsartan, irbesartan), hydrochlorothiazide, angiotensin converting enzyme inhibitors (ramipril and lisinopril) or long acting calcium channel blockers (amlodipine). In combination therapy, aliskiren further decreases blood pressure when combined with either hydrochlorothiazide, amlodipine, irbesartan or ramipril. 4. The biochemical consequences of renin inhibition differ from those of angiotensin I-converting enzyme (ACE) inhibition and Ang II antagonism, particularly in terms of angiotensin profiles and interactions with the bradykinin-nitric oxide-cyclic guanosine monophosphate pathway and possibly the (pro)renin receptor. 5. Blockade of the renin angiotensin system (RAS) with ACE inhibitors, AT1 receptor blockers or a combination of these drugs has become one of the most successful therapeutic approaches in medicine. However, it remains unclear how to optimize RAS blockade to maximize cardiovascular and renal benefits. In this context, renin inhibition to render the RAS fully quiescent is a new possibility requiring further study.

Maligne und therapierefraktäre Hypertonie

Early occurences of organ damage, mainly in the cardiovascular system, the central nervous system, of the kidney or the retina, are hallmarks of a malign course in arterial hypertension. Peracute hypertensive emergencies can lead to a rapid deterioration of organ functions, a slower development is observed in patients with therapy-resistant forms of arterial hypertension. In the following article we discuss the historical trends in terminology and epidemiology, clinical symptoms, and possible causes for therapy-resistant hypertension. The latter mainly focuses on possible secondary forms of hypertension and on thoughts on therapy-resistance in primary, idiopathic arterial hypertension, as well as on possible therapeutic approaches.