Prevalence and prognostic role of resistant hypertension in chronic kidney disease patients

Recent developments in the management of resistant hypertension: focus on endothelin receptor antagonists

Resistant hypertension is characterized by the inability of guideline-recommended triple combination therapy to control blood pressure (BP) to target. It is associated with a significantly increased risk of adverse outcomes. Despite abundant preclinical evidence supporting the critical role of the endothelin pathway in resistant hypertension (RH), clinical implementation of endothelin antagonists for the treatment of hypertension was hindered by various factors. Recently, the novel dual endothelin-receptor antagonist aprocitentan was tested in individuals with resistant hypertension in the PRECISION trial and provided compelling evidence supporting both short and longer-term safety and clinically meaningful and sustained BP lowering efficacy. These findings resulted in the recent regulatory approval of aprocitentan by the FDA. Aprocitentan may be a particularly useful antihypertensive option for individuals with advanced age, chronic kidney disease, and albuminuria.

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.

Apparent Treatment-Resistant Hypertension in the First Year Associated With Cardiovascular Mortality in Peritoneal Dialysis Patients

BACKGROUND

Few reports have focused on the association between apparent treatment-resistant hypertension (aTRH) and cardiovascular (CV) mortality in peritoneal dialysis (PD) population, thus we conducted this retrospective cohort to explore it.

METHODS

This was a retrospective cohort study conducted from January 2011 to January 2020 with PD patients in 4 Chinese dialysis centers. aTRH was defined according to the American College of Cardiology and American Heart Association guidelines. aTRH duration was calculated as the total number of months when patients met the diagnostic criteria in the first PD year. The primary outcome was CV mortality, and the secondary outcomes were CV events, all-cause mortality, combined endpoint (all-cause mortality and transferred to hemodialysis [HD]), and PD withdrawal (all-cause mortality, transferred to HD, and kidney transplantation). Cox proportional hazards models were used to assess the association.

RESULTS

A total of 1,422 patients were finally included in the analysis. During a median follow-up period of 26 months, 83 (5.8%) PD patients incurred CV mortality. The prevalence of aTRH was 24.1%, 19.9%, and 24.6% at 0, 3, and 12 months after PD initiation, respectively. Overall, aTRH duration in the first PD year positively associated with CV mortality (per 3 months increment, adjusted hazards ratio [HR], 1.29; 95% confidence interval 1.10, 1.53; P = 0.002). After categorized, those with aTRH duration more than 6 months presented the highest adjusted HR of 2.92. Similar results were found for secondary outcomes, except for the CV event.

CONCLUSIONS

Longer aTRH duration in the first PD year is associated with higher CV mortality and worse long-term clinical outcomes. Larger studies are warranted to confirm these findings.

CLINICAL TRIALS REGISTRATION

There is no clinical trial registration for this retrospective study.

Real-World Impact of Blood Pressure Control in Patients With Apparent Treatment-Resistant or Difficult-to-Control Hypertension and Stages 3 and 4 Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is a common comorbidity in patients with apparent treatment-resistant hypertension (aTRH). We assessed clinical outcomes, healthcare resource utilization events, and costs in patients with aTRH or difficult-to-control hypertension and stage 3-4 CKD with uncontrolled vs. controlled BP.

METHODS

This retrospective cohort study used linked IQVIA Ambulatory EMR-US and IQVIA PharMetrics Plus claims databases. Adult patients had claims for ≥3 antihypertensive medication classes within 30 days between 01/01/2015 and 06/30/2021, 2 office BP measures recorded 1-90 days apart, ≥1 claim with ICD-9/10-CM diagnosis codes for CKD 3/4, and ≥1 year of continuous enrollment. Baseline BP was defined as uncontrolled (≥130/80 mm Hg) or controlled (<130/80 mm Hg) BP. Outcomes included risk of major adverse cardiovascular events plus (MACE+; stroke, myocardial infarction, heart failure hospitalization), end-stage renal disease (ESRD), healthcare resource utilization events, and costs during follow-up.

RESULTS

Of 3,966 patients with stage 3-4 CKD using ≥3 antihypertensive medications, 2,479 had uncontrolled BP and 1,487 had controlled BP. After adjusting for baseline differences, patients with uncontrolled vs. controlled BP had a higher risk of MACE+ (HR [95% CI]: 1.18 [1.03-1.36]), ESRD (1.85 [1.44-2.39]), inpatient hospitalization (rate ratio [95% CI]: 1.35 [1.28-1.43]), and outpatient visits (1.12 [1.11-1.12]) and incurred higher total medical and pharmacy costs (mean difference [95% CI]: $10,055 [$6,741-$13,646] per patient per year).

CONCLUSIONS

Patients with aTRH and stage 3-4 CKD and uncontrolled BP despite treatment with ≥3 antihypertensive classes had an increased risk of MACE+ and ESRD and incurred greater healthcare resource utilization and medical expenditures compared with patients taking ≥3 antihypertensive classes with controlled BP.

Risk of heart failure in ambulatory resistant hypertension: a meta-analysis of observational studies

The impact of ambulatory resistant hypertension (ARH) on the occurrence of heart failure (HF) is not yet completely known. We performed for the first time a meta-analysis, by using published data or available data from published databases, on the risk of HF in ARH. Patients with ARH (24-h BP ≥ 130/80 mmHg during treatment with ≥3 drugs) were compared with those with controlled hypertension (CH, clinic BP < 140/90 mmHg and 24-h BP < 130/80 mmHg regardless of the number of drugs used), white coat uncontrolled resistant hypertension (WCURH, clinic BP ≥ 140/90 mmHg and 24-h BP < 130/80 mmHg in treated patients) and ambulatory nonresistant hypertension (ANRH, 24-h BP ≥ 130/80 mmHg during therapy with ≤2 drugs). We identified six studies/databases including 21,365 patients who experienced 692 HF events. When ARH was compared with CH, WCURH, or ANRH, the overall adjusted hazard ratio for HF was 2.32 (95% confidence interval (CI) 1.45-3.72), 1.72 (95% CI 1.36-2.17), and 2.11 (95% CI 1.40-3.17), respectively, (all P < 0.001). For some comparisons a moderate heterogeneity was found. Though we did not find variables that could explain the heterogeneity, sensitivity analyses demonstrated that none of the studies had a significant influential effect on the overall estimate. When we evaluated the potential presence of publication bias and small-study effect and adjusted for missing studies identified by Duval and Tweedie's method the estimates were slightly lower but remained significant. This meta-analysis shows that treated hypertensive patients with ARH are at approximately twice the risk of developing HF than other ambulatory BP phenotypes.

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

Resistant Hypertension in Dialysis: Epidemiology, Diagnosis, and Management

Apparent treatment-resistant hypertension is defined as an elevated BP despite the use of ≥3 antihypertensive medications from different classes or the use of ≥4 antihypertensives regardless of BP levels. Among patients receiving maintenance hemodialysis or peritoneal dialysis, using this definition, the prevalence of apparent treatment-resistant hypertension is estimated to be between 18% and 42%. Owing to the lack of a rigorous assessment of some common causes of pseudoresistance, the burden of true resistant hypertension in the dialysis population remains unknown. What distinguishes apparent treatment-resistance from true resistance is white-coat hypertension and adherence to medications. Accordingly, the diagnostic workup of a dialysis patient with apparent treatment-resistant hypertension on dialysis includes the accurate determination of BP control status with the use of home or ambulatory BP monitoring and exclusion of nonadherence to the prescribed antihypertensive regimen. In a patient on dialysis with inadequately controlled BP, despite adherence to therapy with maximally tolerated doses of a β -blocker, a long-acting dihydropyridine calcium channel blocker, and a renin-angiotensin system inhibitor, volume-mediated hypertension is the most important treatable cause of resistance. In daily clinical practice, such patients are often managed with intensification of antihypertensive therapy. However, this therapeutic strategy is likely to fail if volume overload is not adequately recognized or treated. Instead of increasing the number of prescribed BP-lowering medications, we recommend diet and dialysate restricted in sodium to facilitate achievement of dry weight. The achievement of dry weight is facilitated by an adequate time on dialysis of at least 4 hours for delivering an adequate dialysis dose. In this article, we review the epidemiology, diagnosis, and management of resistant hypertension among patients on dialysis.

New trials in resistant hypertension: mixed blessing stories

Resistant hypertension (RH) is linked to an increased risk of cardiovascular and renal complications. Treatment options include non-pharmacological interventions, such as lifestyle modifications, and the use of specific antihypertensive drug combinations, including diuretics. Renal denervation is another option for treatment-resistant hypertension. New compounds targeting different pathways involved in RH-including inhibitors of aminopeptidase A, endothelin antagonists and selective aldosterone synthase inhibitors-have been tested in clinical trials in this condition. The centrally acting drug firibastat, targeting the brain renin-angiotensin system, failed to demonstrate significant effectiveness in reducing blood pressure (BP) in patients with difficult-to-treat and RH in the Firibistat in Resistant Hypertension (FRESH) trial. Aprocitentan, a dual endothelin A and B receptor antagonist, showed a moderate but statistically significant decrease in BP in patients with RH in the Parallel-Group, Phase 3 Study with Aprocitentan in Subjects with Resistant Hypertension (PRECISION) trial. However, concerns remain about potential adverse events, such as fluid retention. The use of baxdrostat, a selective aldosterone synthase inhibitor, showed promising results in reducing BP in patients with treatment-resistant hypertension in the Baxdrostat in Resistant Hypertension (BrigHTN) trial. However, a subsequent trial, HALO, failed to meet its primary endpoint. The unexpected results may be influenced by factors such as patient adherence and white-coat hypertension. Despite the disappointing results from HALO, the potential benefits of inhibiting aldosterone synthesis remain to be fully understood. In conclusion, managing RH remains challenging, and new compounds like firibastat, aprocitentan and baxdrostat have shown varied effectiveness. Further research is needed to improve our understanding and treatment of this condition.

Apparently Resistant Hypertension in Polish Hemodialyzed Population: Prevalence and Risk Factors

BACKGROUND

The aim of this study was to assess the prevalence, characteristics, and determinants of apparent treatment-resistant hypertension (aTRH) in an unselected large population of patients with end-stage kidney disease (ESKD) treated with hemodialysis (HD) throughout the country.

METHODS

A database of 5879 patients (mean age 65.2 ± 14.2 years, 60% of males receiving hemodialysis) was obtained from the biggest provider of hemodialysis in the country. Hypertension and aTRH were defined using pre- or/and post-dialysis BP values. Patients with and without aTRH (non-aTRH) were compared.

RESULTS

Using pre- and post-dialysis criteria, hypertension was diagnosed in 90.7% and 89.1% of subjects, respectively. According to pre- and post-dialysis blood pressure criteria, aTRH incidences were 40.9% and 38.4%, respectively. The hypertensive patients with aTRH versus non-aTRH were younger, had a higher rate of cardiovascular disease, lower dialysis vintage, shorter time on dialysis, higher eKt/V, higher ultrafiltration, higher pre- and post-dialysis BP and HR, and higher use of antihypertensive drugs. Factors that increase the risk of aTRH according to both pre- and post-dialysis BP criteria were age-OR 0.99 [0.98-0.99] and 0.99 [0.98-0.99], the history of CVD 1.26 [1.08-1.46] and 1.30 [1.12-1.51], and diabetes 1.26 [1.08-1.47] and 1.28 [1.09-1.49], adjusted OR with 95% CI.

CONCLUSIONS

In the real-life world, as much as 40% of HD patients may have aTRH. In ESKD HD patients, aTRH seems to be multifactorial, influenced by patient-related rather than dialysis-related factors. Various definitions of aTRH preclude easy comparisons between studies.

Systolic Blood Pressure and Pulse Pressure Are Predictors of Future Cardiovascular Events in Patients with True Resistant Hypertension

Given the increased risk of cardiovascular events associated with resistant hypertension, predictive cardiovascular prognosis is extremely important. Ambulatory blood pressure monitoring (ABPM) is mandatory for resistant hypertension diagnosis, but its use for prognosis is scarce. This observational longitudinal study included 258 patients (mean age of 60.4 ± 11.2 years; 61.2% male), who underwent 24 h ABPM in a hypertension unit from 1999 to 2019. The outcomes were global cardiovascular events (cerebrovascular, coronary, and other cardiovascular events). The mean follow-up period was 6.0 ± 5.0 years. Sixty-eight cardiovascular events (61 nonfatal) were recorded. Patients who experienced cardiovascular events were generally older, with higher rates of chronic kidney disease and prior cardiovascular events. The 24 h systolic blood pressure (hazard ratio 1.44; 95% CI 1.10-1.88), night systolic blood pressure (1.35; 95% CI 1.01-1.80), and 24 h pulse pressure (2.07; 95% CI 1.17-3.67) were independent predictors of global cardiovascular events. Multivariate Cox analysis revealed a higher risk of future cardiovascular events, particularly in patients with a 24 h daytime and nighttime pulse pressure > 60 mm Hg with respective hazard ratios of 1.95; 95% CI 1.01-3.45; 2.15; 95% CI 1.21-3.83 and 2.07; 95% CI 1.17-3.67. In conclusion, APBM is a fundamental tool not only for the diagnosis of resistant hypertension, but also for predicting future cardiovascular events.

Should we CLICK on chlorthalidone for treatment-resistant hypertension in chronic kidney disease?

Treatment-resistant hypertension is common among patients with advanced chronic kidney disease (CKD). In people with preserved kidney function, spironolactone is an evidence-based treatment. However, the risk for hyperkalemia limits its use in people with more advanced CKD. In the Chlorthalidone in Chronic Kidney Disease (CLICK) trial, 160 patients with stage 4 CKD and poorly controlled hypertension as confirmed by 24-hour ambulatory blood pressure (ABP) monitoring were randomly assigned to either placebo or chlorthalidone 12.5 mg daily in a 1:1 ratio stratified by prior loop diuretic use. The primary endpoint was the change in 24-hour systolic ABP from baseline to 12 weeks. The trial showed a treatment-induced reduction of 24-hour systolic ABP by 10.5 mmHg. Of the 160 patients randomized, 113 (71%) had resistant hypertension, of which 90 (80%) were on loop diuretics and the mean number of antihypertensive medications prescribed was 4.1 (standard deviation 1.1). In this subgroup of patients with treatment-resistant hypertension, the adjusted change from baseline to 12 weeks in the between-group difference in 24-hour systolic ABP was -13.9 mmHg (95% CI -19.4 to -8.4; P < .0001). Furthermore, compared with placebo, the urine albumin:creatinine ratio in the chlorthalidone group at 12 weeks was 54% lower (95% CI -65 to -40). Following randomization, hypokalemia, reversible increases in serum creatinine, hyperglycemia, dizziness, orthostatic hypotension and hyperuricemia occurred more frequently in the chlorthalidone group. Chlorthalidone has the potential to improve BP control among patients with advanced CKD and treatment-resistant hypertension. However, caution is advised when treating patients, especially when they are on loop diuretics.

Urinary Dickkopf-3 (DKK3) Is Associated with Greater eGFR Loss in Patients with Resistant Hypertension

Patients with resistant hypertension (HTN) demonstrate an increased risk of chronic kidney disease and progression to end-stage renal disease; however, the individual course of progression is hard to predict. Assessing the stress-induced, urinary glycoprotein Dickkopf-3 (uDKK3) may indicate ongoing renal damage and consecutive estimated glomerular filtration rate (eGFR) decline. The present study aimed to determine the association between uDKK3 levels and further eGFR changes in patients with resistant HTN. In total, 31 patients with resistant HTN were included. Blood pressure and renal function were measured at baseline and up to 24 months after (at months 12 and 24). uDKK3 levels were determined exclusively from the first available spot urine sample at baseline or up to a period of 6 months after, using a commercial ELISA kit. Distinctions between different patient groups were analyzed using the unpaired t-test or Mann-Whitney test. Correlation analysis was performed using Spearman's correlation. The median uDKK3 level was 303 (interquartile range (IQR) 150-865) pg/mg creatinine. Patients were divided into those with high and low eGFR loss (≥3 vs. <3 mL/min/1.73 m²/year). Patients with high eGFR loss showed a significantly higher median baseline uDKK3 level (646 (IQR 249-2555) (n = 13) vs. 180 (IQR 123-365) pg/mg creatinine (n = 18), p = 0.0412 (Mann-Whitney U)). Alternatively, patients could be classified into those with high and low uDKK3 levels (≥400 vs. <400 pg/mg creatinine). Patients with high uDKK3 levels showed significantly higher eGFR loss (-6.4 ± 4.7 (n = 11) vs. 0.0 ± 7.6 mL/min/1.73 m²/year (n = 20), p = 0.0172 (2-sided, independent t-test)). Within the entire cohort, there was a significant correlation between the uDKK3 levels and change in eGFR at the latest follow-up (Spearman's r = -0.3714, p = 0.0397). In patients with resistant HTN, high levels of uDKK3 are associated with higher eGFR loss up to 24 months later.

Thiazide diuretics are back in CKD: the case of chlorthalidone

Sodium and volume excess is the fundamental risk factor underlying hypertension in chronic kidney disease (CKD) patients, who represent the prototypical population characterized by salt-sensitive hypertension. Low salt diets and diuretics constitute the centrepiece for blood pressure control in CKD. In patients with CKD stage 4, loop diuretics are generally preferred to thiazides. Furthermore, thiazide diuretics have long been held as being of limited efficacy in this population. In this review, by systematically appraising published randomized trials of thiazides in CKD, we show that this class of drugs may be useful even among people with advanced CKD. Thiazides cause a negative sodium balance and reduce body fluids by 1-2 l within the first 2-4 weeks and these effects go along with improvement in hypertension control. The recent CLICK trial has documented the antihypertensive efficacy of chlorthalidone, a long-acting thiazide-like diuretic, in stage 4 CKD patients with poorly controlled hypertension. Overall, chlorthalidone use could be considered in patients with treatment-resistant hypertension when spironolactone cannot be administered or must be withdrawn due to side effects. Hyponatremia, hypokalaemia, volume depletion and acute kidney injury are side effects that demand a vigilant attitude by physicians prescribing these drugs. Well-powered randomized trials assessing hard outcomes are still necessary to more confidently recommend the use of these drugs in advanced CKD.

Management of hypertension in advanced kidney disease

PURPOSE OF REVIEW

The aim of this study was to present recent developments in pharmacotherapy of hypertension in patients with advanced chronic kidney disease (CKD).

RECENT FINDINGS

In the AMBER trial, compared with placebo, the potassium-binder patiromer mitigated the risk of hyperkalaemia and enabled more patients with uncontrolled resistant hypertension and stage 3b/4 CKD to tolerate and continue spironolactone treatment; add-on therapy with spironolactone provoked a clinically meaningful reduction of 11-12 mmHg in unattended automated office SBP over 12 weeks of follow-up. In the BLOCK-CKD trial, the investigational nonsteroidal mineralocorticoid-receptor-antagonist (MRA) KBP-5074 lowered office SBP by 7-10 mmHg relative to placebo at 84 days with a minimal risk of hyperkalaemia in patients with advanced CKD and uncontrolled hypertension. The CLICK trial showed that the thiazide-like diuretic chlorthalidone provoked a placebo-subtracted reduction of 10.5 mmHg in 24-h ambulatory SBP at 12 weeks in patients with stage 4 CKD and poorly controlled hypertension.

SUMMARY

Enablement of more persistent spironolactone use with newer potassium-binding agents, the clinical development of novel nonsteroidal MRAs with a more favourable benefit-risk profile and the recently proven blood pressure lowering action of chlorthalidone are three therapeutic opportunities for more effective management of hypertension in high-risk patients with advanced CKD.

Prevalence, phenotypic characteristics and prognostic role of apparent treatment resistant hypertension in the German Chronic Kidney Disease (GCKD) study

Treatment resistant hypertension (TRH) appears of particular relevance in patients with chronic kidney disease (CKD). However, causes and consequences of TRH in CKD patients remain incompletely understood. Therefore, we analyzed the prevalence of apparent TRH (aTRH), and phenotypic characteristics and prognosis associated with aTRH among participants of the German Chronic Kidney Disease (GCKD) study. As insufficient medication adherence has been shown to be a frequent cause of pseudoresistance, we also assessed treatment adherence. Study participants were classified as having aTRH, controlled hypertension and uncontrolled hypertension based on study visit blood pressure and self-reported medication intake. Drug adherence was assessed by comparing self-reported antihypertensive medication with detectable urinary drug metabolites measured by mass spectroscopy. Out of 4901 individuals included in this study, 38% were classified as having aTRH. Male sex, older age, lower estimated glomerular filtration rate (eGFR), higher body mass index (BMI), higher urine albumin-to-creatinine ratio (UACR) and presence of diabetes mellitus were independently associated with higher prevalence of aTRH in a multivariable adjusted regression model. Patients classified as aTRH had higher risk for major adverse cardiovascular events and worsening of kidney disease compared to patients with no aTRH after multivariate adjustment for potential confounders. There was a high agreement between self-reported medication and detectable urinary drug metabolites. In conclusion, in a cohort of Caucasian patients with moderately severe CKD, aTRH was highly prevalent and, in most cases, likely not caused by low medication adherence. Furthermore, aTRH was linked to cardio-renal endpoints, emphasizing the need for improved management.

Primary Aldosteronism and Resistant Hypertension: A Pathophysiological Insight

Primary aldosteronism (PA) is a pathological condition characterized by an excessive aldosterone secretion; once thought to be rare, PA is now recognized as the most common cause of secondary hypertension. Its prevalence increases with the severity of hypertension, reaching up to 29.1% in patients with resistant hypertension (RH). Both PA and RH are "high-risk phenotypes", associated with increased cardiovascular morbidity and mortality compared to non-PA and non-RH patients. Aldosterone excess, as occurs in PA, can contribute to the development of a RH phenotype through several mechanisms. First, inappropriate aldosterone levels with respect to the hydro-electrolytic status of the individual can cause salt retention and volume expansion by inducing sodium and water reabsorption in the kidney. Moreover, a growing body of evidence has highlighted the detrimental consequences of "non-classical" effects of aldosterone in several target tissues. Aldosterone-induced vascular remodeling, sympathetic overactivity, insulin resistance, and adipose tissue dysfunction can further contribute to the worsening of arterial hypertension and to the development of drug-resistance. In addition, the pro-oxidative, pro-fibrotic, and pro-inflammatory effects of aldosterone may aggravate end-organ damage, thereby perpetuating a vicious cycle that eventually leads to a more severe hypertensive phenotype. Finally, neither the pathophysiological mechanisms mediating aldosterone-driven blood pressure rise, nor those mediating aldosterone-driven end-organ damage, are specifically blocked by standard first-line anti-hypertensive drugs, which might further account for the drug-resistant phenotype that frequently characterizes PA patients.

Blood Pressure and Chronic Kidney Disease Progression: An Updated Review

Hypertension (HTN) is common in chronic kidney disease (CKD), and it may aggravate CKD progression. The optimal blood pressure (BP) value in CKD patients is not established yet, although systolic BP ≤130 mmHg is acceptable as a target. Continuous BP monitoring is essential to detect the different variants of high BP and monitor the treatment response. Various methods of BP measurement in the clinic office and at home are currently used. One of these methods is ambulatory BP monitoring (ABPM), by which BP can be closely assessed for even diurnal changes.

We conducted a non-systematic literature review to explore and update the association between high BP and the course of CKD and to review various BP monitoring methods to determine the optimal method for BP recording in CKD patients. PubMed, EMBASE, Google, Google Scholar, and Web Science were searched for published reviews and original articles on BP and CKD by using various phrases and keywords such as "hypertension and CKD", "CKD progression and hypertension", "CKD stage and hypertension", "BP control in CKD", "BP measurement methods", "diurnal BP variation effect on CKD progression", and "types of hypertension." We evaluated and discussed published articles relevant to the review objective. Before preparing the final draft of this article, each author was assigned a section of the topic to read, research deeply, and write a summary about the assigned section. Then a summary of each author's contribution was collected and discussed in several group sessions.

Early detection of high BP is essential to prevent CKD development and progression. Although the latest Kidney Disease Improving Global Outcomes (KDIGO) guidelines suggest that a systolic BP ≤120 mmHg is the target toprevent CKD progression, systolic BP ≤130 mmHg is universally recommended.ABPM is a promising method to diagnose and follow up on BP control; however, the high cost of the new devices and patient unfamiliarity with them have proven to be major disadvantages with regard to this method.

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.

A genome-wide association study identifies a novel candidate locus at the DLGAP1 gene with susceptibility to resistant hypertension in the Japanese population

Numerous genetic variants associated with hypertension and blood pressure are known, but there is a paucity of evidence from genetic studies of resistant hypertension, especially in Asian populations. To identify novel genetic loci associated with resistant hypertension in the Japanese population, we conducted a genome-wide association study with 2705 resistant hypertension cases and 21,296 mild hypertension controls, all from BioBank Japan. We identified one novel susceptibility candidate locus, rs1442386 on chromosome 18p11.3 (DLGAP1), achieving genome-wide significance (odds ratio (95% CI) = 0.85 (0.81–0.90), P = 3.75 × 10⁻⁸) and 18 loci showing suggestive association, including rs62525059 of 8q24.3 (CYP11B2) and rs3774427 of 3p21.1 (CACNA1D). We further detected biological processes associated with resistant hypertension, including chemical synaptic transmission, regulation of transmembrane transport, neuron development and neurological system processes, highlighting the importance of the nervous system. This study provides insights into the etiology of resistant hypertension in the Japanese population.

Persistent Resistant Hypertension Has Worse Renal Outcomes in Chronic Kidney Disease than that Resolved in Two Years: Results from the KNOW-CKD Study

Apparent treatment-resistant hypertension (ATRH) is closely related to chronic kidney disease (CKD); however, the long-term outcomes and the effects of improvement in ATRH in patients with CKD are not well understood. We evaluated the relationship between the persistence of ATRH and the progression of CKD. This cohort study enrolled 1921 patients with CKD. ATRH was defined as blood pressure above 140/90 mmHg and intake of three different types of antihypertensive agents, including diuretics, or intake of four or more different types of antihypertensive agents, regardless of blood pressure. We defined ATRH subgroups according to the ATRH status at the index year and two years later. The prevalence of ATRH at baseline was 14.0%. The presence of ATRH at both time points was an independent risk factor for end-point renal outcome (HR, 1.41; 95% CI, 1.04–1.92; p = 0.027). On the other hand, the presence of ATRH at any one of the time points was not statistically significant. In conclusion, persistent ATRH is more important for the prognosis of renal disease than the initial ATRH status. Continuous follow-up and appropriate treatment are important to improve the renal outcomes.

Hypertension in Chronic Kidney Disease (CKD): Diagnosis, Classification, and Therapeutic Targets

Blood pressure (BP) in the office is often recorded without standardization of the technique of measurement. When office BP measurement is performed with a research-grade methodology, it can inform better therapeutic decisions. The reference-standard method of ambulatory BP monitoring (ABPM) together with the assessment of BP in the office enables the identification of white-coat and masked hypertension, facilitating the stratification of cardiorenal risk. Compared with general population, the prevalence of resistant hypertension is 2- to 3-fold higher among patients with chronic kidney disease (CKD). The use of ABPM is mandatory in order to exclude the white-coat effect, a common cause of pseudoresistance, and confirm the diagnosis of true-resistant hypertension. After the premature termination of Systolic Blood Pressure Intervention Trial due to an impressive cardioprotective benefit of intensive BP-lowering, the 2017 American Heart Association/American College of Cardiology guideline reappraised the definition of hypertension and recommended a tighter BP target of <130/80 mm Hg for the majority of adults with a high cardiovascular risk profile, inclusive of patients with CKD. However, the benefit/risk ratio of intensive BP-lowering in particular subsets of patients with CKD (i.e., those with diabetes or more advanced CKD) continues to be debated. We explore the controversial issue of BP targets in CKD, providing a critical evaluation of the available clinical-trial evidence and guideline recommendations. We argue that the systolic BP target in CKD, if BP is measured correctly, should be <120 mm Hg.

Resistant Hypertension in Chronic Kidney Disease (CKD): Prevalence, Treatment Particularities, and Research Agenda

PURPOSE OF REVIEW

To explore the prevalence, treatment particularities, and research agenda in the management of resistant hypertension among patients with chronic kidney disease (CKD).

RECENT FINDINGS

The prevalence of resistant hypertension is reported to be 2-3 times higher in patients with CKD than in the general hypertensive population. Based in part on the results of the PATHWAY-2 trial showing add-on spironolactone to be superior to placebo or active treatment with an α- or β-blocker in reducing BP, international guidelines recommend the use of spironolactone as fourth-line agent in pharmacotherapy of resistant hypertension. Despite the several-fold higher burden of resistant hypertension among patients with stage 3b-4 CKD, the use of spironolactone in this population has been restricted, mainly due to the risk of hyperkalemia. The recently reported AMBER trial showed that among patients with uncontrolled resistant hypertension and an estimated glomerular filtration rate of 25-45 ml/min/1.73m², the newer potassium-binder patiromer prevented the development of hyperkalemia and increased the proportion of participants who remained on add-on spironolactone over 12 weeks of follow-up. Administration of spironolactone was associated with a clinically meaningful reduction of 11-12 mmHg in unattended automated office systolic blood pressure (BP) over the course of the AMBER trial. Newer potassium-binding therapies overcome the barrier of hyperkalemia and facilitate the persistent use of spironolactone, which is an effective add-on therapy to control BP in patients with resistant hypertension and advanced CKD. Future trials are now warranted to explore whether this strategy confers benefits on "hard" clinical outcomes in this high-risk population.

Sodium Intake and Chronic Kidney Disease

In Chronic Kidney Disease (CKD) patients, elevated blood pressure (BP) is a frequent finding and is traditionally considered a direct consequence of their sodium sensitivity. Indeed, sodium and fluid retention, causing hypervolemia, leads to the development of hypertension in CKD. On the other hand, in non-dialysis CKD patients, salt restriction reduces BP levels and enhances anti-proteinuric effect of renin-angiotensin-aldosterone system inhibitors in non-dialysis CKD patients. However, studies on the long-term effect of low salt diet (LSD) on cardio-renal prognosis showed controversial findings. The negative results might be the consequence of measurement bias (spot urine and/or single measurement), reverse epidemiology, as well as poor adherence to diet. In end-stage kidney disease (ESKD), dialysis remains the only effective means to remove dietary sodium intake. The mismatch between intake and removal of sodium leads to fluid overload, hypertension and left ventricular hypertrophy, therefore worsening the prognosis of ESKD patients. This imposes the implementation of a LSD in these patients, irrespective of the lack of trials proving the efficacy of this measure in these patients. LSD is, therefore, a rational and basic tool to correct fluid overload and hypertension in all CKD stages. The implementation of LSD should be personalized, similarly to diuretic treatment, keeping into account the volume status and true burden of hypertension evaluated by ambulatory BP monitoring.

Apparent Treatment-Resistant Hypertension Assessed by Office and Ambulatory Blood Pressure in Chronic Kidney Disease-A Report from the Chronic Renal Insufficiency Cohort Study

Background

Apparent treatment-resistant hypertension is common in patients with CKD. Whether measurement of 24-hour ambulatory BP monitoring is valuable for risk-stratifying patients with resistant hypertension and CKD is unclear.

Methods

We analyzed data from the Chronic Renal Insufficiency Cohort study, a prospective study of participants (n=1186) with CKD. Office BP was measured using standardized protocols; ambulatory BP was measured using Spacelabs monitors. Apparent treatment-resistant hypertension was defined on the basis of office BP, ambulatory BP monitoring, and use of more than three antihypertensive medications. Outcomes were composite cardiovascular disease, kidney outcomes, and mortality. Groups were compared using Cox regression analyses with a control group of participants without apparent treatment-resistant hypertension.

Results

Of 475 participants with apparent treatment-resistant hypertension on the basis of office BP, 91.6% had apparent treatment-resistant hypertension confirmed by ambulatory BP monitoring. Unadjusted event rates of composite cardiovascular disease, kidney outcomes, and mortality were higher in participants with ambulatory BP monitoring-defined apparent treatment-resistant hypertension compared with participants without apparent treatment-resistant hypertension. In adjusted analyses, the risks of composite cardiovascular disease (hazard ratio, 1.27; 95% confidence interval [95% CI], 0.59 to 2.7), kidney outcomes (hazard ratio, 1.68; 95% CI, 0.88 to 3.21), and mortality (hazard ratio, 1.27; 95% CI, 0.5 to 3.25) were not statistically significantly higher in participants with ambulatory BP monitoring-defined apparent treatment-resistant hypertension compared with participants without apparent treatment-resistant hypertension.

Conclusions

In our study population with CKD, most patients with apparent treatment-resistant hypertension defined on the basis of office BP have apparent treatment-resistant hypertension confirmed by ambulatory BP monitoring. Although ABPM-defined apparent treatment-resistant hypertension was not independently associated with clinical outcomes, it identified participants at high risk for adverse clinical outcomes.

Prognostic Importance of On-Treatment Clinic and Ambulatory Blood Pressures in Resistant Hypertension: A Cohort Study

The prognostic importances of on-treatment clinic and ambulatory blood pressure (BP) levels have never been investigated in individuals with resistant hypertension. We aimed to evaluate them for the occurrence of incident cardiovascular and mortality outcomes in a prospective cohort of 1726 patients with resistant hypertension. Clinic and ambulatory BPs were measured at baseline and serially during follow-up (analyzed as time-varying and as mean cumulative BPs) and also categorized as controlled/uncontrolled as defined by the traditional and new 2017 American College of Cardiology/American Heart Association criteria. Multivariate Cox analyses examined the associations between BP parameters and the occurrence of total cardiovascular events, major adverse cardiovascular events, and cardiovascular and all-cause mortalities. C statistics and the integrated discrimination improvement indexes evaluated the improvement in risk discrimination. Over a median follow-up of 8.3 years, 417 total cardiovascular events occurred (358 major adverse cardiovascular events) and 391 individuals died (233 cardiovascular deaths). All single systolic BP (SBP) parameters significantly predicted all outcomes, but the associations were stronger for ambulatory SBPs than for clinic SBPs and for on-treatment SBPs (particularly for mean cumulative) than for baseline SBPs, and both improved risk discrimination (with increases in C statistic of up to 0.021 and integrated discrimination improvements of up to 19.7%). These findings were consistent for diastolic BPs. Uncontrolled ambulatory BPs were associated with higher risks for all outcomes, whereas uncontrolled clinic BPs were not. In conclusion, mean cumulative ambulatory BPs during follow-up were the best prognostic markers of adverse cardiovascular outcomes and mortality in patients with resistant hypertension. Serial ambulatory BP monitoring shall be more widely used in resistant hypertension management.

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.

Resistant hypertension-defining the scope of the problem

The updated scientific statement by the American Heart Association has defined resistant hypertension (HTN;RH) as uncontrolled blood pressure (BP) ≥ 130/80 mmHg, despite concurrent use of 3 anti-HTN drug classes comprising a calcium channel blocker, a blocker of renin-angiotensin system, and a thiazide diuretic, preferably chlorthalidone. Using the updated BP criteria, the prevalence of RH in the United States is found to be modestly increased by approximately 3-4% among treated population. Meta-analysis of observational studies have demonstrated that pseudo-RH from white coat HTN or medication nonadherence is as much common as the truly RH. Thus, screening for pseudo-resistance in the evaluation of all apparent RH is of utmost importance as diagnosis of white-coat HTN requires no treatment, while medication nonadherence would benefit from identifying and targeting barriers to adherence.

Molecular Mechanisms of Primary Aldosteronism

Primary aldosteronism (PA) results from excess production of mineralocorticoid hormone aldosterone by the adrenal cortex. It is normally caused either by unilateral aldosterone-producing adenoma (APA) or by bilateral aldosterone excess as a result of bilateral adrenal hyperplasia. PA is the most common cause of secondary hypertension and associated morbidity and mortality. While most cases of PA are sporadic, an important insight into this debilitating disease has been derived through investigating the familial forms of the disease that affect only a minor fraction of PA patients. The advent of gene expression profiling has shed light on the genes and intracellular signaling pathways that may play a role in the pathogenesis of these tumors. The genetic basis for several forms of familial PA has been uncovered in recent years although the list is likely to expand. Recently, the work from several laboratories provided evidence for the involvement of mammalian target of rapamycin pathway and inflammatory cytokines in APAs; however, their mechanism of action in tumor development and pathophysiology remains to be understood.

Sodium toxicity in peritoneal dialysis: mechanisms and "solutions"

The major trials in peritoneal dialysis (PD) have demonstrated that increasing peritoneal clearance of small solutes is not associated with any advantage on survival, whereas sodium and fluid overload heralds higher risk of death and technique failure. On the other hand, higher sodium and fluid overload due to loss of residual kidney function (RKF) and higher transport membrane is associated with poor patient and technique survival. Recent experimental studies also show that, independently from fluid overload, sodium accumulation in the peritoneal interstitium exerts direct inflammatory and angiogenetic stimuli, with consequent structural and functional changes of peritoneum, while in patients with Chronic Kidney Disease sodium stored in interstitial skin acts as independent determinant of left ventricular hypertrophy. Noteworthy, this tissue pool of sodium is modifiable being removed by dialysis. Therefore, novel PD strategies to optimize sodium removal, including the use of bimodal and/or low-sodium solutions, are actively tested. Nonetheless, a holistic approach aimed at preserving peritoneal function and the kidney may represent the key of therapy success in the hard task of preserving adequate sodium balance in PD patients. In this review, we describe the available evidence on sodium toxicity in PD, either related or unrelated to fluid overload, and we also discuss about possible "solutions" to preserve or restore sodium balance in PD patients.

Extracellular Fluid Volume Is an Independent Determinant of Uncontrolled and Resistant Hypertension in Chronic Kidney Disease: A NephroTest Cohort Study

Background

Hypertension is highly prevalent during chronic kidney disease (CKD) and, in turn, worsens CKD prognosis. We aimed to describe the determinants of uncontrolled and resistant hypertension during CKD.

Methods and Results

We analyzed baseline data from patients with CKD stage 1 to 5 (NephroTest cohort) who underwent thorough renal explorations, including measurements of glomerular filtration rate (clearance of ⁵¹Cr‐EDTA) and of extracellular water (volume of distribution of the tracer). Hypertension was defined as blood pressure (BP; average of 3 office measurements) ≥140/90 mm Hg or the use of antihypertensive drugs. In 2015 patients (mean age, 58.7±15.3 years; 67% men; mean glomerular filtration rate, 42±15 mL/min per 1.73 m²), prevalence of hypertension was 88%. Among hypertensive patients, 44% and 32% had uncontrolled (≥140/90 mm Hg) and resistant (uncontrolled BP despite 3 drugs, including a diuretic, or ≥4 drugs, including a diuretic, regardless of BP level) hypertension, respectively. In multivariable analysis, extracellular water, older age, higher albuminuria, diabetic nephropathy, and the absence of aldosterone blockers were independently associated with uncontrolled BP. Extracellular water, older age, lower glomerular filtration rate, higher albuminuria and body mass index, male sex, African origin, diabetes mellitus, and diabetic and glomerular nephropathies were associated with resistant hypertension.

Conclusions

In this large population of patients with CKD, a lower glomerular filtration rate, a higher body mass index, diabetic status, and African origin were associated with hypertension severity but not with BP control. Higher extracellular water, older age, and higher albuminuria were independent determinants of both resistant and uncontrolled hypertension during CKD. Our results advocate for the large use of diuretics in this population.

Patiromer versus placebo to enable spironolactone use in patients with resistant hypertension and chronic kidney disease (AMBER): a phase 2, randomised, double-blind, placebo-controlled trial

BACKGROUND

Spironolactone is effective at reducing blood pressure in patients with uncontrolled resistant hypertension. However, the use of spironolactone in patients with chronic kidney disease can be restricted by hyperkalaemia. We evaluated use of the potassium binder patiromer to allow more persistent use of spironolactone in patients with chronic kidney disease and resistant hypertension.

METHODS

In this phase 2 multicentre, randomised, double-blind, placebo-controlled study, we enrolled participants aged 18 years and older with chronic kidney disease (estimated glomerular filtration rate 25 to ≤45 mL/min per 1·73 m²) and uncontrolled resistant hypertension from 62 outpatient centres in ten countries (Bulgaria, Croatia, Georgia, Hungary, Ukraine, France, Germany, South Africa, the UK, and the USA). Patients meeting all eligibility criteria at the final screening visit were stratified by local serum potassium measurement (4·3 to <4·7 mmol/L vs 4·7 to 5·1 mmol/L) and history of diabetes. Participants were randomly assigned (1:1) with an interactive web response system to receive either placebo or patiromer (8·4 g once daily), in addition to open-label spironolactone (starting at 25 mg once daily) and their baseline blood pressure medications. Participants, the study team that administered treatments and measured blood pressure, and the investigators were masked to assigned treatment groups. Dose titrations were permitted after 1 week (patiromer) and 3 weeks (spironolactone). The primary endpoint was the between-group difference at week 12 in the proportion of patients on spironolactone. Efficacy endpoints and safety were assessed in all randomised patients (intention to treat). The study was registered with Clinicaltrials.gov, NCT03071263.

FINDINGS

Between Feb 13, 2017, and Aug 20, 2018, we screened 574 patients. 295 (51%) of 574 patients met all inclusion criteria and were randomly assigned to spironolactone in addition to double-blind treatment with either placebo (n=148) or patiromer (n=147). At week 12, 98 (66%) of 148 patients in the placebo group and 126 (86%) of 147 patients in the patiromer group remained on spironolactone (between-group difference 19·5%, 95% CI 10·0-29·0; p<0·0001). Adverse events were mostly mild or moderate in severity and occurred in 79 (53%) of 148 patients in the placebo group and 82 (56%) of 147 patients in the patiromer group.

INTERPRETATION

In patients with resistant hypertension and chronic kidney disease, patiromer enabled more patients to continue treatment with spironolactone with less hyperkalaemia. Persistent spironolactone enablement in this population of patients has clinical relevance for the treatment of resistant hypertension.

FUNDING

Relypsa, a Vifor Pharma Group Company.

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.

Management of hyperkalemia in patients with kidney disease: a position paper endorsed by the Italian Society of Nephrology

Hyperkalemia (HK) is the most common electrolyte disturbance observed in patients with kidney disease, particularly in those in whom diabetes and heart failure are present or are on treatment with renin-angiotensin-aldosterone system inhibitors (RAASIs). HK is recognised as a major risk of potentially life threatening cardiac arrhythmic complications. When an acute reduction of renal function manifests, both in patients with chronic kidney disease (CKD) and in those with previously normal renal function, HK is the main indication for the execution of urgent medical treatment and the recourse to extracorporeal replacement therapies. In patients with end-stage renal disease, the presence of HK not responsive to medical therapy is an indication at the beginning of chronic renal replacement therapy. HK can also be associated indirectly with the progression of CKD, because the finding of high potassium values leads to withdrawal of treatment with RAASIs, which constitute the first choice nephro-protective treatment. It is therefore essential to identify patients at risk of developing HK, and to implement therapeutic interventions aimed at preventing and treating this dangerous complication of kidney disease. Current strategies aimed at the prevention and treatment of HK are still unsatisfactory, as evidenced by the relatively high prevalence of HK also in patients under stable nephrology care, and even in the ideal setting of randomized clinical trials where optimal treatment and monitoring are mandatory. This position paper will review the main therapeutic interventions to be implemented for the prevention, detection and treatment of HK in patients with CKD on conservative care, in those on dialysis, in patients in whom renal disease is associated with diabetes, heart failure, resistant hypertension and who are on treatment with RAASIs, and finally in those presenting with severe acute HK.

Achieving control of resistant hypertension: Not just the number of blood pressure medications

Resistant hypertension (RH) has a prevalence of around 12% and is associated with an increased risk of cardiovascular disease, progression to end-stage renal disease, and even mortality. In 2017, the American College of Cardiology and American Heart Association released updated guidelines that detail steps to ensure proper diagnosis of RH, including the exclusion of pseudoresistance. Lifestyle modifications, such as low salt diet and physical exercise, remain at the forefront of optimizing blood pressure control. Secondary causes of RH also need to be investigated, including screening for obstructive sleep apnea. Notably, the guidelines demonstrate a major change in medication management recommendations to include mineralocorticoid receptor antagonists. In addition to advances in medication optimization, there are several device-based therapies that have been showing efficacy in the treatment of RH. Renal denervation therapy has struggled to show efficacy for blood pressure control, but with a re-designed catheter device, it is once again being tested in clinical trials. Carotid baroreceptor activation therapy (BAT) via an implantable pulse generator has been shown to be effective in lowering blood pressure both acutely and in long-term follow up data, but there is some concern about the safety profile. Both a second-generation pulse generator and an endovascular implant are being tested in new clinical trials with hopes for improved safety profiles while maintaining therapeutic efficacy. Both renal denervation and carotid BAT need continued study before widespread clinical implementation. Central arteriovenous anastomosis has emerged as another possible therapy and is being actively explored. The ongoing pursuit of blood pressure control is a vital part of minimizing adverse patient outcomes. The future landscape appears hopeful for helping patients achieve blood pressure goals not only through the optimization of antihypertensive medications but also through device-based therapies in select individuals.

Apparent Treatment-Resistant Hypertension and Cardiovascular Risk in Hemodialysis Patients: Ten-Year Outcomes of the Q-Cohort Study

There has been limited data discussing the relationship between apparent treatment-resistant hypertension (ATRH) and cardiovascular disease risk in patients receiving maintenance hemodialysis. We analyzed data for 2999 hypertensive patients on maintenance hemodialysis. ATRH was defined as uncontrolled blood pressure despite the use of three or more classes of antihypertensive medications, or four or more classes of antihypertensive medications regardless of blood pressure level. We examined the relationships between ATRH and cardiovascular events using a Cox proportional hazards model. The proportion of participants with ATRH was 18.0% (539/2999). During follow-up (median: 106.6 months, interquartile range: 51.3-121.8 months), 931 patients experienced cardiovascular events including coronary heart disease (n = 424), hemorrhagic stroke (n = 158), ischemic stroke (n = 344), and peripheral arterial disease (n = 242). Compared with the non-ATRH group, the ATRH group showed a significant increased risk of developing cardiovascular disease (hazard ratio [HR]: 1.27; 95% confidence interval [CI]: 1.08-1.49), coronary heart disease (HR: 1.28; 95% CI: 1.01-1.62), ischemic stroke (HR: 1.31; 95% CI: 1.01-1.69), and peripheral arterial disease (HR: 1.42; 95% CI: 1.06-1.91) even after adjusting for potential confounders. This study demonstrated that ATRH was significantly associated with increased cardiovascular risk in hemodialysis patients.

Antihypertensive therapy prescribing patterns and correlates of blood pressure control among hypertensive patients with chronic kidney disease

We used electronic health records (EHRs) data from 5658 ambulatory chronic kidney disease (CKD) patients with hypertension and prescribed antihypertensive therapy to examine antihypertensive drug prescribing patterns, blood pressure (BP) control, and risk factors for resistant hypertension (RHTN) in a real-world setting. Two-thirds of CKD patients and three-fourths of those with proteinuria were prescribed guideline-recommended renoprotective agents including an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB); however, one-third were not prescribed an ACEI or ARB. CKD patients, particularly those with stages 1-2 CKD, who were prescribed regimens including beta-blocker (BB) + diuretic or ACEI/ARB + BB + diuretic were more likely to have controlled BP (<140/90 mm Hg) compared to those prescribed other combinations. Risk factors for RHTN included African American race and major comorbidities. Clinicians may use these findings to tailor antihypertensive therapy to the needs of each patient, including providing CKD stage-specific treatment, and better identify CKD patients at risk of RHTN.

BP Measurement Techniques: What They Mean for Patients with Kidney Disease

Patients with CKD typically have hypertension. Manual BP measurement in the office setting was used to define hypertension, establish eligibility, and assess BP targets in the epidemiologic studies and early randomized, controlled trials that inform current management of hypertension. Use of automated oscillometric devices has largely replaced manual BP measurement in the office and clinical trials. These newer devices may reduce the white coat effect and facilitate guideline-adherent measurement protocols. Obtaining BP measurements outside of the office with home and ambulatory BP monitoring is now more common. Out of office BPs are especially important in patients with CKD, because reduced GFR and proteinuria are associated with masked hypertension (normal office BP and elevated BP outside of the office), elevated nighttime BP, and abnormal diurnal variation in BP, all of which are associated with higher risk for target organ damage and adverse outcomes. Also, it is now feasible to routinely measure central BP and central hemodynamics. These measures are of greater importance to patients with CKD given the higher prevalence of increased sympathetic tone, arteriosclerosis, and inflammation as well as impaired sodium excretion and endothelial dysfunction, which lead to alterations in central BPs in this population. In this review, we describe various BP measurement techniques and how they apply to the care of patients with CKD.

Dietary Salt Restriction in Chronic Kidney Disease: A Meta-Analysis of Randomized Clinical Trials

Background. A clear evidence on the benefits of reducing salt in people with chronic kidney disease (CKD) is still lacking. Salt restriction in CKD may allow better control of blood pressure (BP) as shown in a previous systematic review while the effect on proteinuria reduction remains poorly investigated. Methods. We performed a meta-analysis of randomized controlled trials (RCTs) evaluating the effects of low versus high salt intake in adult patients with non-dialysis CKD on change in BP, proteinuria and albuminuria. Results. Eleven RCTs were selected and included information about 738 CKD patients (Stage 1–4); urinary sodium excretion was 104 mEq/day (95%CI, 76–131) and 179 mEq/day (95%CI, 165–193) in low- and high-sodium intake subgroups, respectively, with a mean difference of −80 mEq/day (95%CI from −107 to −53; p <0.001). Overall, mean differences in clinic and ambulatory systolic BP were −4.9 mmHg (95%CI from −6.8 to −3.1, p <0.001) and −5.9 mmHg (95%CI from −9.5 to −2.3, p <0.001), respectively, while clinic and ambulatory diastolic BP were −2.3 mmHg (95%CI from −3.5 to −1.2, p <0.001) and −3.0 mmHg (95%CI from −4.3 to −1.7; p <0.001), respectively. Mean differences in proteinuria and albuminuria were −0.39 g/day (95%CI from −0.55 to −0.22, p <0.001) and −0.05 g/day (95%CI from −0.09 to −0.01, p = 0.013). Conclusion. Moderate salt restriction significantly reduces BP and proteinuria/albuminuria in patients with CKD (Stage 1–4).

Cardiovascular disease risk factors in chronic kidney disease: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is a global health burden and is independently associated with increased cardiovascular disease risk. Assessment of cardiovascular risk in the general population using prognostic models based on routinely collected risk factors is embedded in clinical practice. In CKD, prognostic models may misrepresent risk due to the interplay of traditional atherosclerotic and non-traditional risk factors. This systematic review's aim was to identify routinely collected risk factors for inclusion in a CKD-specific cardiovascular prognostic model.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Systematic review and meta-analysis of observational cohort studies and randomized controlled trials. Studies identified from MEDLINE and Embase searches using a pre-defined and registered protocol (PROSPERO ID-2016:CRD42016036187). The main inclusion criteria were individuals ≥18 years of age with non-endstage CKD. Routinely collected risk factors where multi-variable adjustment for established cardiovascular risk factors had occurred were extracted. The primary outcome was fatal and non-fatal cardiovascular events.

RESULTS

The review of 3,232, abstracts identified 29 routinely collected risk factors of which 20 were presented in more than 1 cohort. 21 cohorts were identified in relation to 27,465 individuals and 100,838 person-years. In addition to established traditional general population cardiovascular risk factors, left ventricular hypertrophy, serum albumin, phosphate, urate and hemoglobin were all found to be statistically significant in their association with future cardiovascular events.

CONCLUSIONS

These non-traditional risk factors should be assessed in the development of future cardiovascular prognostic models for use in individuals with CKD.

Resistant and undertreated hypertension in patients with chronic kidney disease: data from the PATRIOTIC survey

BACKGROUND

Hypertension is prevalent in chronic kidney disease (CKD), but the control of hypertension is suboptimal. We reported the prevalence and characteristics of resistant and undertreated hypertension based on a nationwide survey aiming to improve blood pressure (BP) control.

METHODS

Resistant hypertension (RH) was defined as BP above the target (<140/90 mm Hg) despite the use of 3 antihypertensive drugs or achieving the target BP by using ≥4 antihypertensive drugs. Undertreated hypertension was defined as uncontrolled hypertension (unCH) using ≤2 drugs. We compared the characteristics and antihypertensive treatment among different groups (including RH and unCH using ≤2 drugs). Multivariable logistic regression was used to detect factors associated with unCH using ≤2 drugs and RH.

RESULTS

4,435 nondialysis CKD patients with hypertension were analyzed, and 36.9% of participants achieved controlled hypertension (CH) using ≤3 drugs, 11.1% met the criteria for RH, and 52% had unCH despite the use of ≤ 2 antihypertensive drugs. Participants with unCH using ≤ 2 drugs had low usage of renin-angiotensin system blockers (36.8%) and diuretics (5.5%), which was much lower than participants with CH using ≤3 drugs and RH (P< 0.05). After multivariable adjustment, obesity, advanced CKD stages, urinary protein level of ≥1.5 g/24 h, diabetes, and cardiovascular disease were associated with RH in CKD patients (P< 0.05).

CONCLUSION

Compared with RH, undertreated hypertension contributes more to the unCH in Chinese CKD patients. It is important to ensure adequate antihypertensive treatment, including choosing antihypertensive drugs, that guidelines recommended.

Resistant Hypertension: Mechanisms and Treatment

PURPOSE OF REVIEW

Emerging evidence suggests that multiple mechanisms may be responsible for the development of treatment-resistant hypertension (TRH). This review aims to summarize recent data on potential mechanisms of resistance and discuss current pharmacotherapeutic options available in the management of TRH.

RECENT FINDINGS

Excess sodium and fluid retention, increased activation of the renin-angiotensin-aldosterone system, and heightened activity of the sympathetic nervous system appear to play an important role in development of TRH. Emerging evidence also suggests a role for arterial stiffness and, potentially, gut dysbiosis. Therapeutic approaches for TRH should include diuretic optimization and the addition of aldosterone antagonists as the preferred fourth agent in most patients. Further therapeutic approaches may be guided by the suspected underlying mechanism of TRH in conjunction with other patient-specific factors. The pathophysiology of TRH is multifaceted; however, increasing evidence supports several mechanisms that may be targeted to improve blood pressure control among patients with TRH. Further studies are needed to determine whether such approaches may be more effective than usual care.

Resistant Hypertension and Cardiorenovascular Risk

Studies have documented independent contribution of sympathetic activation to the cardiovascular disease continuum. Hypertension is one of the leading modifiable factors. Most if not all the benefit of antihypertensive treatment depends on blood pressure lowering, regardless how it is obtained. Resistant hypertension is defined as blood pressure that remains uncontrolled in spite of the concurrent use of three antihypertensive drugs of different classes. Ideally, one of the three drugs should be a diuretic, and all drugs should be prescribed at optimal dose amounts. Poor adherence to antihypertensive therapy, undiscovered secondary causes (e.g. obstructive sleep apnea, primary aldosteronism, renal artery stenosis), and lifestyle factors (e.g. obesity, excessive sodium intake, heavy alcohol intake, various drug interactions) are the most common causes of resistant hypertension. Cardio(reno)vascular morbidity and mortality are significantly higher in resistant hypertensive than in general hypertensive population, as such patients are typically presented with a long-standing history of poorly controlled hypertension. Early diagnosis and treatment is needed to avoid further end-organ damage to prevent cardiorenovascular remodeling. Treatment strategy includes lifestyle changes, adding a mineralocorticoid receptor antagonist, treatment adherence in cardiovascular prevention and, in case of failure to control blood pressure, renal sympathetic denervation or baroreceptor activation therapy. The comparative outcomes in resistant hypertension deserve better understanding. In this review, the most current approaches to resistant hypertension and cardiovascular risk based on the available literature evidence will be discussed.

Resistant Hypertension, Time-Updated Blood Pressure Values and Renal Outcome in Type 2 Diabetes Mellitus

Background

Apparent treatment resistant hypertension (aTRH) is highly prevalent in patients with type 2 diabetes mellitus (T2D) and entails worse cardiovascular prognosis. The impact of aTRH and long‐term achievement of recommended blood pressure (BP) values on renal outcome remains largely unknown. We assessed the role of aTRH and BP on the development of chronic kidney disease in patients with T2D and hypertension in real‐life clinical practice.

Methods and Results

Clinical records from a total of 29 923 patients with T2D and hypertension, with normal baseline estimated glomerular filtration rate and regular visits during a 4‐year follow‐up, were retrieved and analyzed. The association between time‐updated BP control (ie, 75% of visits with BP <140/90 mm Hg) and the occurrence of estimated glomerular filtration rate <60 and/or a reduction ≥30% from baseline was assessed. At baseline, 17% of patients had aTRH. Over the 4‐year follow‐up, 19% developed low estimated glomerular filtration rate and 12% an estimated glomerular filtration rate reduction ≥30% from baseline. Patients with aTRH showed an increased risk of developing both renal outcomes (adjusted odds ratio, 1.31 and 1.43; P<0.001 respectively), as compared with those with non‐aTRH. No association was found between BP control and renal outcomes in non‐aTRH, whereas in aTRH, BP control was associated with a 30% (P=0.036) greater risk of developing the renal end points.

Conclusions

ATRH entails a worse renal prognosis in T2D with hypertension. BP control is not associated with a more‐favorable renal outcome in aTRH. The relationship between time‐updated BP and renal function seems to be J‐shaped, with optimal systolic BP values between 120 and 140 mm Hg.

Management of Hypertension in Patients with Chronic Kidney Disease

Hypertension is the leading factor in the global burden of disease. It is the predominant modifiable risk factor for stroke, heart disease, and kidney failure. Chronic kidney disease (CKD) is both a common cause and sequel of uncontrolled hypertension. The pathophysiology of CKD-associated hypertension is complex and multi-factorial. This paper reviews the key pathogenic mechanisms of CKD-associated hypertension, the importance of standardized blood pressure (BP) measurement in establishing the diagnosis and management plus the significance of ambulatory BP monitoring for assessment of diurnal BP variation commonly seen in CKD. The optimal BP target in CKD remains a matter of discussion despite recent clinical trials. Medical therapy can be difficult and challenging. In addition to lifestyle modification and dietary salt restriction, treatment may need to be individualized based on co-morbidities. Combination of antihypertensive drugs, including appropriate diuretic choice and dose, is of great significance in hypertension management in CKD.