Incident ESRD and treatment-resistant hypertension: the reasons for geographic and racial differences in stroke (REGARDS) study

Diagnosis and management of resistant hypertension

Resistant hypertension is defined as blood pressure that remains above the therapeutic goal despite concurrent use of at least three antihypertensive agents of different classes, including a diuretic, with all agents administered at maximum or maximally tolerated doses. Resistant hypertension is also diagnosed if blood pressure control requires four or more antihypertensive drugs. Assessment requires the exclusion of apparent treatment resistant hypertension, which is most often the result of non-adherence to treatment. Resistant hypertension is associated with major cardiovascular events in the short and long term, including heart failure, ischemic heart disease, stroke, and renal failure. Guidelines from several professional organizations recommend lifestyle modification and antihypertensive drugs. Medications typically include an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, a calcium channel blocker, and a long acting thiazide-type/like diuretic; if a fourth drug is needed, evidence supports addition of a mineralocorticoid receptor antagonist. After a long pause since 2007 when the last antihypertensive class was approved, several novel agents are now under active development. Some of these may provide potent blood pressure lowering in broad groups of patients, such as aldosterone synthase inhibitors and dual endothelin receptor antagonists, whereas others may provide benefit by allowing treatment of resistant hypertension in special populations, such as non-steroidal mineralocorticoid receptor antagonists in patients with chronic kidney disease. Several device based approaches have been tested, with renal denervation being the best supported and only approved interventional device treatment for resistant hypertension.

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.

Characterization of Individuals With Apparent Resistant Hypertension Using Contemporary Guidelines: Insights From CV-QUIC

BACKGROUND

Apparent resistant hypertension (aRH) carries excess cardiovascular risk beyond nonresistant forms of hypertension; however, our understanding of this at-risk population, as defined by current US practice guidelines, is limited. Accordingly, we sought to evaluate the prevalence, clinical characteristics, and pharmacotherapeutic patterns of patients with aRH using contemporary blood pressure guidance.

METHODS

We classified patients at 3 large healthcare systems by hypertensive status using contemporary hypertension guidelines. We subsequently described the demographic and clinical characteristics of patients with aRH and compared these factors among hypertensive patients without aRH and between those with controlled and uncontrolled aRH.

RESULTS

A total of 2 420 468 patients were analyzed, of whom 1 343 489 (55.6%) were hypertensive according to contemporary guidelines. Among hypertensive patients, 11 992 (8.5%) met criteria for aRH, with nearly all assessed comorbid conditions, particularly diabetes and heart failure, being more common in those with aRH. When compared with patients with uncontrolled aRH, those with controlled aRH were more frequently prescribed a beta-blocker, diuretic, and nitrate, with the largest standardized difference observed for a mineralocorticoid receptor antagonist (35.4% versus 10.4%, Cohen D 0.62). Consistent findings were noted in sensitivity analyses using the blood pressure threshold of 140/90 mm Hg.

CONCLUSIONS

In an analysis of over 2.4 million individuals, a lower prevalence of aRH was observed than previously reported (12%-15%), but with a high burden of comorbidities. Identification of differences in pharmacotherapy between patients with controlled and uncontrolled aRH, particularly lower rates of mineralocorticoid receptor antagonist use, help define potential opportunities to improve care and lower cardiovascular risk.

Association of uncontrolled blood pressure in apparent treatment-resistant hypertension with increased risk of major adverse cardiovascular events plus

Patients with apparent treatment-resistant hypertension (aTRH) are at increased risk of end-organ damage and cardiovascular events. Little is known about the effects of blood pressure (BP) control in this population. Using a national claims database integrated with electronic medical records, the authors evaluated the relationships between uncontrolled BP (UBP; ≥130/80 mmHg) or controlled BP (CBP; <130/80 mmHg) and risk of major adverse cardiovascular events plus (MACE+; stroke, myocardial infarction, heart failure requiring hospitalization) and end-stage renal disease (ESRD) in adult patients with aTRH (taking ≥3 antihypertensive medication classes concurrently within 30 days between January 1, 2015 and June 30, 2021). MACE+ components were also evaluated separately. Multivariable regression models were used to adjust for baseline differences in demographic and clinical characteristics, and sensitivity analyses using CBP <140/90 mmHg were conducted. Patients with UBP (n = 22 333) were younger and had fewer comorbidities at baseline than those with CBP (n = 11 427). In the primary analysis, which adjusted for these baseline differences, UBP versus CBP patients were at an 8% increased risk of MACE+ (driven by a 31% increased risk of stroke) and a 53% increased risk of ESRD after 2.7 years of follow-up. Greater MACE+ (22%) and ESRD (98%) risk increases with UBP versus CBP were seen in the sensitivity analysis. These real-world data showed an association between suboptimal BP control in patients with aTRH and higher incidence of MACE+ and ESRD linked with UBP despite the use of multidrug regimens. Thus, there remains a need for improved aTRH management.

Trends in using of antihypertensive medication among US CKD adults, NHANES 2001-2018

Objective

Blood pressure (BP) control rates among adult patients taking antihypertensive medications in the United States have not improved over the last decade. Many CKD adults require more than one class of antihypertensive agent to reach the BP target recommended by the guidelines. However, no study has quantified the proportion of adult CKD patients taking antihypertensive medication who are on monotherapy or combination therapy.

Methods

National Health and Nutrition Examination Survey data during 2001-2018 was used, including adults with CKD taking antihypertensive medication (age ≥ 20 years, n = 4,453). BP control rates were investigated under the BP targets recommended by the 2021 KDIGO, the 2012 KDIGO, and the 2017 ACC/AHA guidelines.

Results

The percentages of uncontrolled BP among US adults with CKD taking antihypertensive medication were 81.4% in 2001-2006 and 78.2% in 2013-2018. The proportion of monotherapy of antihypertensive regimen were 38.6, 33.3, and 34.6% from 2001 to 2006, 2007-2012, and 2013-2018, with no obvious difference. Similarly, there was no significant change in percentages of dual-therapy, triple-therapy, and quadruple-therapy. Although proportion of CKD adults not treated with ACEi/ARB decreased from 43.5% in 2001-2006 to 32.7% in 2013-2018, treatment of ACEi/ARB among patients with ACR > 300 mg/g had no significant change.

Conclusion

The BP control rates among US adult CKD patients taking antihypertensive medications have not improved from 2001 to 2018. Mono-therapy accounted for about one third of adult CKD patients taking antihypertensive medication and not changed. Increasing antihypertensive medication combination therapy may help improve BP control in CKD adults in the United States.

Comparative Safety and Effectiveness of Aldosterone Antagonists Versus Beta-Blockers as Fourth Agents in Patients With Apparent Resistant Hypertension

BACKGROUND

Limited evidence exists regarding long-term effectiveness and safety of aldosterone antagonists (AAs) versus beta blockers (BBs) as fourth-line antihypertensive agents in patients with resistant hypertension (RH). We evaluated the comparative effectiveness and safety of aldosterone AA versus BB.

METHODS

We conducted a real-world retrospective cohort study using IBM MarketScan commercial claims and Medicare Supplemental claims (2007-2019). Patients with RH entered the cohort (ie, index date) when they newly initiated either AA or BB. The effectiveness outcome was major adverse cardiovascular events. Safety outcomes were hyperkalemia, gynecomastia, and kidney function deterioration. Potential confounding was addressed by adjustment for baseline characteristics via stabilized inverse probability of treatment weighting (SIPTW) based on propensity scores. Cox proportional hazards regression with SIPTWs were used to estimate adjusted hazard ratio (aHR) and 95% CI comparing risk for outcomes between AA and BB groups.

RESULTS

We identified 80 598 patients with RH (mean age: 61 years, 51% males), of which 6626 initiated AA and 73 972 initiated BB as the fourth antihypertensive agent. Among patients with RH, initiation of AA as a fourth-line antihypertensive agent did not significantly reduce major adverse cardiovascular event risk relative to BB initiation (aHR, 0.77 [95% CI, 0.50-1.19]) but did substantially increase the risk of hyperkalemia (aHR, 3.86 [95% CI, 2.78-5.34]), gynecomastia (aHR, 9.51 [95% CI, 5.69-15.89]), and kidney function deterioration (aHR, 1.63 [95% CI, 1.34-1.99]).

CONCLUSIONS

Long-term clinical trials powered to assess major adverse cardiovascular events are necessary to understand the risk-benefit trade-off of AA as fourth-line therapy for RH.

SMOC2 gene interacts with APOL1 in the development of end-stage kidney disease: A genome-wide association study

Background

Some but not all African-Americans (AA) who carry APOL1 nephropathy risk variants (APOL1) develop kidney failure (end-stage kidney disease, ESKD). To identify genetic modifiers, we assessed gene-gene interactions in a large prospective cohort of the REasons for Geographic and Racial Differences in Stroke (REGARDS) study.

Methods

Genotypes from 8,074 AA participants were obtained from Illumina Infinium Multi-Ethnic AMR/AFR Extended BeadChip. We compared 388 incident ESKD cases with 7,686 non-ESKD controls, using a two-locus interaction approach. Logistic regression was used to examine the effect of APOL1 risk status (using recessive and additive models), single nucleotide polymorphism (SNP), and APOL1*SNP interaction on incident ESKD, adjusting for age, sex, and ancestry. APOL1 *SNP interactions that met the threshold of 1.0 × 10-5 were replicated in the Genetics of Hypertension Associated Treatment (GenHAT) study (626 ESKD cases and 6,165 controls). In a sensitivity analysis, models were additionally adjusted for diabetes status. We conducted additional replication in the BioVU study.

Results

Two APOL1 risk alleles prevalence (recessive model) was similar in the REGARDS and GenHAT studies. Only one APOL1-SNP interaction, for rs7067944 on chromosome 10, ~10 KB from the PCAT5 gene met the genome-wide statistical threshold (P interaction = 3.4 × 10-8), but this interaction was not replicated in the GenHAT study. Among other relevant top findings (with P interaction < 1.0 × 10-5), a variant (rs2181251) near SMOC2 on chromosome six interacted with APOL1 risk status (additive) on ESKD outcomes (REGARDS study, P interaction =5.3 × 10-6) but the association was not replicated (GenHAT study, P interaction = 0.07, BioVU study, P interaction = 0.53). The association with the locus near SMOC2 persisted further in stratified analyses. Among those who inherited ≥1 alternate allele of rs2181251, APOL1 was associated with an increased risk of incident ESKD (OR [95%CI] = 2.27[1.53, 3.37]) but APOL1 was not associated with ESKD in the absence of the alternate allele (OR [95%CI] = 1.34[0.96, 1.85]) in the REGARDS study. The associations were consistent after adjusting for diabetes.

Conclusion

In a large genome-wide association study of AAs, a locus SMOC2 exhibited a significant interaction with the APOL1 locus. SMOC2 contributes to the progression of fibrosis after kidney injury and the interaction with APOL1 variants may contribute to an explanation for why only some APOLI high-risk individuals develop ESKD.

Refractory Arterial Hypertension: Features of Neurohormonal and Water-salt Imbalanceand Approaches to Antihypertensive Drug Therapy

Refractory arterial hypertension is characterized by a lack of control of target blood pressure, despite the prolonged use >5 antihypertensive drugs with different mechanisms of action, including longacting diuretic chlorthalidone and the mineralcorticoid receptor antagonists (spironolactone or eplerenone). The review presents the results of clinical studies devoted the elucidating peculiarities of the neurohormonal status and water-salt balance in such patients and developing new approaches to antihypertensive drug therapy based on them. According to these studies, individuals with refractory hypertension differ from patients with resistant hypertension with the higher of sympathetic nervous system activity and the absence of an increased of intrathoracic fluid volume, which indirectly indicates a significant decrease in the intravascular fluid volume. In this regard, the review focuses on the data obtained in assessing the clinical efficacy of sympatholytics clonidine and reserpine in patients with resistant and refractory hypertension, as well as renal sodium-glucose co-transporter type 2 inhibitors, which suppress the sympathetic nervous system activity and can be used to overcome refractory hypertension in patients with type 2 diabetes.

Rethinking Resistant Hypertension

Resistant hypertension is common and known to be a risk factor for cardiovascular events, including stroke, myocardial infarction, heart failure, and cardiovascular mortality, as well as adverse renal events, including chronic kidney disease and end-stage kidney disease. This review will discuss the definition of resistant hypertension as well as the most recent evidence regarding its diagnosis, evaluation, and management. The issue of medication non-adherence and its association with apparent treatment-resistant hypertension will be addressed. Non-pharmacological interventions for the treatment of resistant hypertension will be reviewed. Particular emphasis will be placed on pharmacological interventions, highlighting the role of mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors and device therapy, including renal denervation, baroreceptor activation or modulation, and central arteriovenous fistula creation.

Russian Medical Society for Arterial Hypertension expert consensus. Resistant hypertension: detection and management

The diagnosis of resistant arterial hypertension allows us to single out a separate group of patients in whom it is necessary to use special diagnostic methods and approaches to treatment. Elimination of reversible factors leading to the development of resistant arterial hypertension, such as non-adherence to therapy, inappropriate therapy, secondary forms of arterial hypertension, leads to an improvement in the patient's prognosis. Most patients with resistant hypertension should be evaluated to rule out primary aldosteronism, renal artery stenosis, chronic kidney disease, and obstructive sleep apnea. The algorithm for examining patients, recommendations for lifestyle changes and a step-by-step therapy plan can improve blood pressure control. It is optative to use the most simplified treatment regimen and long-acting combined drugs. For a separate category of patients, it is advisable to perform radiofrequency denervation of the renal arteries.

What Evolutionary Evidence Implies About the Identity of the Mechanoelectrical Couplers in Vascular Smooth Muscle Cells

Loss of pressure-induced vasoconstriction increases susceptibility to renal and cerebral vascular injury. Favored paradigms underlying initiation of the response include transient receptor potential channels coupled to G protein-coupled receptors or integrins as transducers. Degenerin channels may also mediate the response. This review addresses the 1) evolutionary role of these molecules in mechanosensing, 2) limitations to identifying mechanosensitive molecules, and 3) paradigm shifting molecular model for a VSMC mechanosensor.

Risk of Kidney Failure in Patients With Cancer: A South Korean Population-Based Cohort Study

RATIONALE & OBJECTIVE

Reduced kidney function is associated with an increased risk of cancer; however, it is unclear if cancer increases the risk of kidney failure with replacement therapy (KFRT). We assessed the risk of KFRT among patients with various types of cancer collectively and with specific types of cancer.

STUDY DESIGN

Retrospective population-based cohort study.

SETTING & PARTICIPANTS

A total of 2,473,095 participants with (n = 824,365) or without (n = 1,648,730) cancer registered in the Korean National Health Insurance Service database.

PREDICTORS

Cancer and cancer subtypes defined using International Classification of Diseases, 10th Revision, Clinical Modification, codes.

OUTCOMES

Primary outcome was KFRT defined as the initiation of hemodialysis or peritoneal dialysis or kidney transplantation.

ANALYTICAL APPROACH

For each patient with cancer, 2 controls matched for age, sex, estimated glomerular filtration rate, diabetes, and hypertension were included. To address the competing risk of death, a competing risk survival analysis was conducted using the Fine and Gray method.

RESULTS

Occurrence of KFRT was higher in patients with cancer than in controls without cancer (incidence rates of 1.07 vs 0.51 cases per 1,000 person-years). Competing risk analysis showed that cancer was significantly associated with an increased risk of KFRT after adjusting for other potential predictors (adjusted hazard ratio, 2.29 [95% CI, 2.20-2.39]). Multiple myeloma, leukemia, lymphoma, and kidney, ovarian, and liver cancer were most significantly associated with an increased KFRT risk, with multiple myeloma conferring the highest risk across age and sex groups. All subgroups of patients with cancer (based on age, sex, smoking, alcohol, exercise, obesity, and comorbid conditions) exhibited a higher risk of KFRT.

LIMITATIONS

Causal association between cancer and kidney outcomes could not be confirmed.

CONCLUSIONS

Patients with cancer, particularly those with multiple myeloma, exhibited an increased risk of KFRT after accounting for the competing risk of death.

Association of Apparent Treatment-Resistant Hypertension With Differential Risk of End-Stage Kidney Disease Across Racial Groups in the Million Veteran Program

[Figure: see text].

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.

Hypertension Canada's 2020 Comprehensive Guidelines for the Prevention, Diagnosis, Risk Assessment, and Treatment of Hypertension in Adults and Children

Hypertension Canada's 2020 guidelines for the prevention, diagnosis, risk assessment, and treatment of hypertension in adults and children provide comprehensive, evidence-based guidance for health care professionals and patients. Hypertension Canada develops the guidelines using rigourous methodology, carefully mitigating the risk of bias in our process. All draft recommendations undergo critical review by expert methodologists without conflict to ensure quality. Our guideline panel is diverse, including multiple health professional groups (nurses, pharmacy, academics, and physicians), and worked in concert with experts in primary care and implementation to ensure optimal usability. The 2020 guidelines include new guidance on the management of resistant hypertension and the management of hypertension in women planning pregnancy.

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.

Special Article - The management of resistant hypertension: A 2020 update

Resistant hypertension (RH) induces higher morbidity and mortality due to cardiovascular disease and stroke than hypertension without treatment resistance. New guidelines define RH as blood pressure (BP) ≥130/80 mmHg in a patient taking ≥3 antihypertensive agents of different classes or BP <130/80 mmHg in a patient taking ≥4 antihypertensive drugs. According to the new definition, pseudo-resistance due to error in BP measurement, white coat effect and medication nonadherence must be excluded to make the diagnosis of RH. This 2020 update focuses on the lifestyle and antihypertensive drug management of RH and includes recent proof-of-principle trials of renal nerve ablation in hypertension. Stepwise evidence-based pharmacologic treatment of RH includes optimization of the 3-drug regimen, substitution of a thiazide-like for a thiazide diuretic and addition of a mineralocorticoid receptor antagonist as the fourth drug. Non-evidence-based recommendations include addition of a β-blocker as the fifth drug and switching to a minoxidil-based regimen as the final step in achieving BP control.

Aggravated endothelial endocrine dysfunction and intimal thickening of renal artery in high-fat diet-induced obese pigs following renal denervation

Background

Renal denervation (RDN) targeting the sympathetic nerves in the renal arterial adventitia as a treatment of resistant hypertension can cause endothelial injury and vascular wall injury. This study aims to evaluate the risk of atherosclerosis induced by RDN in renal arteries.

Methods

A total of 15 minipigs were randomly assigned to 3 groups: (1) control group, (2) sham group, and (3) RDN group (n = 5 per group). All pigs were fed a high-fat diet (HFD) for 6 months after appropriate treatment. The degree of intimal thickening of renal artery and the conversion of endothelin 1 (ET-1) receptors were evaluated by histological staining. Western blot was used to assess the expression of nitric oxide (NO) synthesis signaling pathway, ET-1 and its receptors, NADPH oxidase 2 (NOX2) and 4-hydroxynonenal (4-HNE) proteins, and the activation of NF-kappa B (NF-κB).

Results

The histological staining results suggested that compared to the sham treatment, RDN led to significant intimal thickening and significantly promoted the production of endothelin B receptor (ET_BR) in vascular smooth muscle cells (VSMCs). Western blotting analysis indicated that RDN significantly suppressed the expression of AMPK/Akt/eNOS signaling pathway proteins, and decreased the production of NO, and increased the expression of endothelin system proteins including endothelin-1 (ET-1), endothelin converting enzyme 1 (ECE1), endothelin A receptor (ET_AR) and ET_BR; and upregulated the expression of NOX2 and 4-HNE proteins and enhanced the activation of NF-kappa B (NF-κB) when compared with the sham treatment (all p < 0.05). There were no significant differences between the control and sham groups (all p > 0.05).

Conclusions

RDN aggravated endothelial endocrine dysfunction and intimal thickening, and increased the risk of atherosclerosis in renal arteries of HFD-fed pigs.

Uncontrolled Arterial Hypertension: Kidney, Neurohormonal Imbalance, and Approaches to Antihypertensive Drug Therapy

Resistant and refractory arterial hypertensions are two distinct clinical phenotypes of uncontrolled arterial hypertension (AH), which differ in their sensitivity to antihypertensive drug therapy. The review presents data obtained in clinical studies devoted to elucidating the involvement of disorders of neurohormonal status and renal function in the formation of resistant and refractory arterial hypertension, to and the development of new approaches to increasing the effectiveness of antihypertensive therapy in these patient’s populations. The results of these studies have shown that in patients with uncontrolled arterial hypertension, despite prolonged intake ≥ 3 antihypertensive drugs with different mechanisms of action, including a diuretic, excess sodium reabsorption persists in the distal segments of nephron due to increased aldosterone activity and sympathetic nervous system hyperactivity. In this regard, special attention has been paid to the data of PATHWAY-2, PATHWAY-3 and ReHOT trials that in patients with resistant AH tested the clinical efficacy of spironolactone, amiloride, and antiadrenergic drugs bisoprolol, doxazosin and clonidine, suppressing activity of the sympathetic nervous system.

Antihypertensive drug use in resistant and nonresistant hypertension and in controlled and uncontrolled resistant hypertension

BACKGROUND AND AIM

Treatment-resistant hypertension (TRH) is associated with particular clinical features, nonadherence, and suboptimal treatment. We assessed possible associations of antihypertensive drug classes, specific agents inside each class, and types of combinations, with the presence of non-TRH vs. TRH, and with controlled vs. uncontrolled TRH.

METHODS

Comparisons were done in 14 264 patients treated with three drugs (non-TRH: 2988; TRH: 11 276) and in 6974 treated with at least four drugs (controlled TRH: 1383; uncontrolled TRH: 5591). Associations were adjusted for age, sex, and previous cardiovascular event.

RESULTS

In both groups of patients treated with three or with at least four drugs, aldosterone antagonists among drug classes [adjusted odds ratio (OR): 1.82 and 1.41, respectively], and ramipril (OR: 1.28 and 1.30), olmesartan (OR: 1.31 and 1.37), and amlodipine (OR: 1.11 and 1.41) inside each class were significantly associated with blood pressure control (non-TRH or controlled TRH). In patients treated with three drugs, non-TRH was also associated with the use of chlorthalidone (OR: 1.50) and bisoprolol (OR: 1.19), whereas in patients treated with at least four drugs, controlled TRH was significantly associated with the triple combination of a renin-angiotensin system blocker, a calcium channel blocker, and a diuretic (OR: 1.17).

CONCLUSION

The use of aldosterone antagonists is associated with blood pressure control in patients treated with three or more drugs. Similar results are observed with specific agents inside each class, being ramipril, olmesartan, chlorthalidone, amlodipine, and bisoprolol those exhibiting significant results. An increased use of these drugs might probably reduce the burden of TRH.

Prevalence of Apparent Treatment-Resistant Hypertension in the United States According to the 2017 High Blood Pressure Guideline

OBJECTIVE

To evaluate the prevalence of apparent treatment-resistant hypertension (aTR-hypertension) in US adults with treated hypertension by using the nationally representative National Health and Nutrition Examination Survey (NHANES).

PATIENTS AND METHODS

Nonpregnant US adults older than 20 years with a self-reported history of treated hypertension who had blood pressure measured in NHANES cycles 2007 to 2014 were included in this study. Study participants were stratified into 4 groups according to average blood pressure and antihypertensive medication use: well-controlled hypertension, undertreated hypertension, aTR-hypertension by the 2017 guideline, and aTR-hypertension by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guideline. National Health and Nutrition Examination Survey sample weights were used to estimate the national prevalence.

RESULTS

From 2007 to 2014, 5512 participants with treated hypertension representing 46.7 million people nationally were included. Compared with JNC 7 guideline criteria, application of the 2017 high blood pressure guideline criteria increased the prevalence of aTR-hypertension in US adults with treated hypertension from 12.0% to 15.95%, identifying an additional 1.85 million individuals with aTR-hypertension nationally. Individuals newly reclassified as having aTR-hypertension were younger. However, the prevalence of thiazide diuretic use remained less than 70%, and that of mineralocorticoid antagonist use remained less than 10% regardless of the guideline definition.

CONCLUSION

On the basis of the 2017 high blood pressure guideline, the prevalence of aTR-hypertension is 15.95% in US adults with treated hypertension. This represents an absolute increase of 4% (1.85 million additional individuals nationally) compared with the JNC 7 guideline definition, with a consistent increase across all subpopulations with treated hypertension.

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.

Chronic kidney disease and incident apparent treatment-resistant hypertension among blacks: Data from the Jackson Heart Study

It is unclear whether black patients with chronic kidney disease (CKD) vs those without CKD who take antihypertensive medication have an increased risk for apparent treatment-resistant hypertension (aTRH). The authors analyzed 1741 Jackson Heart Study participants without aTRH taking antihypertensive medication at baseline. aTRH was defined as uncontrolled blood pressure while taking three antihypertensive medication classes or taking four or more antihypertensive medication classes, regardless of blood pressure level. CKD was defined as an albumin to creatinine ratio ≥30 mg/g or estimated glomerular filtration rate <60 mL/min/1.73 m² . Over 8 years, 20.1% of participants without CKD and 30.5% with CKD developed aTRH. The multivariable-adjusted hazard ratio for aTRH comparing participants with CKD vs those without CKD was 1.45 (95% CI, 1.12-1.86). Participants with an albumin to creatinine ratio ≥30 vs <30 mg/g (hazard ratio, 1.44; 95% CI, 1.04-2.00) and estimated glomerular filtration rate of 45 to 59 mL/min/1.73 m² and <45 vs ≥60mL/min/1.73 m² (hazard ratio, 1.60 [95% CI, 1.16-2.20] and 2.05 [95% CI, 1.28-3.26], respectively) were more likely to develop aTRH.

Prevalence and clinical characteristics of apparent therapy-resistant hypertension in patients with cardiovascular disease: a cross-sectional cohort study in secondary care

OBJECTIVES

Our aim was to investigate the prevalence of apparent therapy-resistant hypertension (aTRH) in patients with clinical manifest cardiovascular disease (CVD), and to study clinical characteristics related to aTRH in this population.

SETTING

The SMART (Second Manifestations of ARTerial disease) study is a large, single-centre cohort study in secondary care.

PARTICIPANTS

Office blood pressure (BP) at inclusion was used to evaluate BP control in 6191 hypertensive patients with clinical manifest (cardio)vascular disease. Therapy-resistant hypertension was defined as BP ≥140/90 mm Hg despite use of antihypertensive drugs from ≥3 drug classes including a diuretic or use of ≥4 antihypertensive drugs irrespective of BP. Logistic regression analysis was used to explore the relationship between clinical characteristics measured at baseline and presence of aTRH.

RESULTS

The prevalence of aTRH was 9.1% (95% CI 8.4 to 9.8). Prevalence increased with age and when albuminuria was present and was higher in patients with lower estimated glomerular filtration rate (eGFR). Presence of aTRH was related to diabetes, female sex, duration and multiple locations of vascular disease, body mass index and waist circumference. Carotid intima-media thickness was higher (0.99±0.28 vs 0.93±0.28 mm) and ankle-brachial index lower (1.07±0.20 vs 1.10±0.19) in patients with aTRH compared with patients without aTRH.

CONCLUSION

aTRH is prevalent in patients with clinical manifest CVD and is related to clinical factors known to be related with increased vascular risk, and with lower eGFR.

Refractory versus resistant hypertension: Novel distinctive phenotypes

Resistant hypertension (RHTN) is relatively common with an estimated prevalence of 10-20% of treated hypertensive patients. It is defined as blood pressure (BP) >140/90 mmHg treated with ≥3 antihypertensive medications, including a diuretic, if tolerated. Refractory hypertension is a novel phenotype of severe antihypertensive treatment failure. The proposed definition for refractory hypertension, i.e. BP >140/90 mmHg with use of ≥5 different antihypertensive medications, including a diuretic and a mineralocorticoid receptor antagonist (MRA) has been applied inconsistently. In comparison to RHTN, refractory hypertension seems to be less prevalent than RHTN. This review focuses on current knowledge about this novel phenotype compared with RHTN including definition, prevalence, mechanisms, characteristics and comorbidities, including cardiovascular risk. In patients with RHTN excess fluid retention is thought to be a common mechanism for the development of RHTN. Recently, evidence has emerged suggesting that refractory hypertension may be more of neurogenic etiology due to increased sympathetic activity as opposed to excess fluid retention. Treatment recommendations for RHTN are generally based on use and intensification of diuretic therapy, especially with the combination of a long-acting thiazide-like diuretic and an MRA. Based on findings from available studies, such an approach does not seem to be a successful strategy to control BP in patients with refractory hypertension and effective sympathetic inhibition in such patients, either with medications and/or device based approaches may be needed.

Clinico-pathological characteristics and outcomes of patients with biopsy-proven hypertensive nephrosclerosis: a retrospective cohort study

Background

This study aimed to investigate renal outcomes and their predictors in biopsy-proven hypertensive nephrosclerosis (HN) patients and to compare clinico-pathological characteristics and prognoses between benign nephrosclerosis (BN) and malignant nephrosclerosis (MN) patients.

Methods

Data for biopsy-proven HN patients were retrospectively analyzed. Renal survival rates and relationships between clinico-pathological characteristics and outcomes were assessed.

Results

A total of 194 patients were enrolled; the mean age at biopsy was 43.8 years, and male gender predominated (82.5 %). The median duration of hypertension was 5.0 years, and the mean systolic and diastolic blood pressures were 195 ± 37 and 126 ± 26 mmHg, respectively. The median serum creatinine (Scr) level, estimated glomerular filtration rate (eGFR), and proteinuria level were 1.61 mg/dl, 49.6 ml/min/1.73 m², and 0.80 g/24 h, respectively. BN and MN were found by renal biopsy in 55.2 % and 44.8 % of patients, respectively. At biopsy, MN patients were younger, and had higher median Scr and proteinuria levels, higher incidences of anemia, hypertensive heart disease and hypertensive retinopathy, and worse renal outcomes than BN patients. During a median follow-up period of 3.0 years, 36 patients (18.6 %) reached end-stage renal disease (ESRD), and the 5- and 10-year cumulative renal survival rates for HN patients were 84.5 % and 48.9 %, respectively. A decreased baseline eGFR, an increased baseline proteinuria level, anemia, increased percentage of global glomerulosclerosis and tubular atrophy and interstitial fibrosis (TAIF) were independent predictors of future ESRD.

Conclusions

The clinico-pathological characteristics and prognoses were significantly different between the MN and BN patients. The renal outcomes of HN patients were independently associated with the baseline eGFR and proteinuria level, anemia, percentage of global glomerulosclerosis and TAIF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0254-2) contains supplementary material, which is available to authorized users.

Prevalence and Prognostic Significance of Apparent Treatment Resistant Hypertension in Chronic Kidney Disease: Report From the Chronic Renal Insufficiency Cohort Study

The association between apparent treatment resistant hypertension (ATRH) and clinical outcomes is not well studied in chronic kidney disease. We analyzed data on 3367 hypertensive participants in the Chronic Renal Insufficiency Cohort (CRIC) to determine prevalence, associations, and clinical outcomes of ATRH in nondialysis chronic kidney disease patients. ATRH was defined as blood pressure ≥140/90 mm Hg on ≥3 antihypertensives, or use of ≥4 antihypertensives with blood pressure at goal at baseline visit. Prevalence of ATRH was 40.4%. Older age, male sex, black race, diabetes mellitus, and higher body mass index were independently associated with higher odds of having ATRH. Participants with ATRH had a higher risk of clinical events than participants without ATRH-composite of myocardial infarction, stroke, peripheral arterial disease, congestive heart failure (CHF), and all-cause mortality (hazard ratio [95% confidence interval], 1.38 [1.22-1.56]); renal events (1.28 [1.11-1.46]); CHF (1.66 [1.38-2.00]); and all-cause mortality (1.24 [1.06-1.45]). The subset of participants with ATRH and blood pressure at goal on ≥4 medications also had higher risk for composite of myocardial infarction, stroke, peripheral arterial disease, CHF, and all-cause mortality (hazard ratio [95% confidence interval], (1.30 [1.12-1.51]) and CHF (1.59 [1.28-1.99]) than those without ATRH. ATRH was associated with significantly higher risk for CHF and renal events only among those with estimated glomerular filtration rate ≥30 mL/min per 1.73 m(2). Our findings show that ATRH is common and associated with high risk of adverse outcomes in a cohort of patients with chronic kidney disease. This underscores the need for early identification and management of patients with ATRH and chronic kidney disease.

The double challenge of resistant hypertension and chronic kidney disease

Resistant hypertension is defined as blood pressure above goal despite adherence to a combination of at least three optimally dosed antihypertensive medications, one of which is a diuretic. Chronic kidney disease is the most frequent of several patient factors or comorbidities associated with resistant hypertension. The prevalence of resistant hypertension is increased in patients with chronic kidney disease, while chronic kidney disease is associated with an impaired prognosis in patients with resistant hypertension. Recommended low-salt diet and triple antihypertensive drug regimens that include a diuretic, should be complemented by the sequential addition of other antihypertensive drugs. New therapeutic innovations for resistant hypertension, such as renal denervation and carotid barostimulation, are under investigation especially in patients with advanced chronic kidney disease. We discuss resistant hypertension in chronic kidney disease stages 3-5 (ie, patients with an estimated glomerular filtration rate below 60 mL/min per 1·73 m(2) and not on dialysis), in terms of worldwide epidemiology, outcomes, causes and pathophysiology, evidence-based treatment, and a call for action.

Catheter-based renal denervation for resistant hypertension: Twenty-four month results of the EnligHTN I first-in-human study using a multi-electrode ablation system

BACKGROUND

Long term safety and efficacy data of multi-electrode ablation system for renal denervation (RDN) in patients with drug resistant hypertension (dRHT) are limited.

METHODS AND RESULTS

We studied 46 patients (age: 60 ± 10 years, 4.7 ± 1.0 antihypertensive drugs) with drug resistant hypertension (dRHT). Reduction in office BP at 24 months from baseline was -29/-13 mmHg, while the reduction in 24-hour ambulatory BP and in home BP at 24 months were -13/-7 mmHg and -11/-6 mmHg respectively (p<0.05 for all). A correlation analysis revealed that baseline office and ambulatory BP were related to the extent of office and ambulatory BP drop. Apart from higher body mass index (33.3 ± 4.7 vs 29.5 ± 6.2 kg/m(2), p<0.05), there were no differences in patients that were RDN responders defined as ≥10 mmHg decrease (74%, n=34) compared to non-responders. Stepwise logistic regression analysis revealed no prognosticators of RDN response (p=NS for all). At 24 months there were no new serious device or procedure related adverse events.

CONCLUSIONS

The EnligHTN I study shows that the multi-electrode ablation system provides a safe method of RDN in dRHT accompanied by a clinically relevant and sustained BP reduction.

Pathophysiology and treatment of resistant hypertension: the role of aldosterone and amiloride-sensitive sodium channels

Resistant hypertension is a clinically distinct subgroup of hypertension defined by the failure to achieve blood pressure control on optimal dosing of at least 3 antihypertensive medications of different classes, including a diuretic. The pathophysiology of hypertension can be attributed to aldosterone excess in more than 20% of patients with resistant hypertension. Existing dogma attributes the increase in blood pressure seen with increases in aldosterone to its antinatriuretic effects in the distal nephron. However, emerging research, which has identified and has begun to define the function of amiloride-sensitive sodium channels and mineralocorticoid receptors in the systemic vasculature, challenges impaired natriuresis as the sole cause of aldosterone-mediated resistant hypertension. This review integrates these findings to better define the role of the vasculature and aldosterone in the pathophysiology of resistant hypertension. In addition, a brief guide to the treatment of resistant hypertension is presented.

Sleep-disordered breathing and resistant hypertension

Hypertension is a highly prevalent problem worldwide, affecting at least one third of the adult general population. Although the exact prevalence is uncertain, it is estimated that at least 15% to 20% of individuals with hypertension have resistant hypertension. Resistant hypertension has been shown to predict more adverse cardiovascular and renal outcomes. In 2003, the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure recognized obstructive sleep apnea (OSA) as an important cause of secondary hypertension. A large body of epidemiologic evidence has linked OSA to resistant hypertension, nondipping nocturnal blood pressure, as well as target organ damage, including left ventricular hypertrophy, arterial stiffness, and microalbuminuria. The importance of OSA as a risk factor for the development of hypertension independent of other confounding factors also was observed in a prospective longitudinal study. More importantly, OSA predicts an increased risk of adverse cardiovascular outcomes, mortality, and sudden cardiac death. This article discusses the associations between OSA and resistant hypertension and reviews the latest understanding on the pathophysiologic mechanisms of hypertension in OSA. Nocturnal continuous positive airway pressure therapy is regarded as the standard treatment for OSA. Prospective randomized controlled trials and meta-analyses of prospective randomized controlled trials within the past 10 years that have examined the effects of continuous positive airway pressure therapy on blood pressure control in patients with OSA with or without hypertension are reviewed and summarized. The majority of the trials suggest a modest but significant benefit on blood pressure control with continuous positive airway pressure therapy. Whether continuous positive airway pressure therapy may improve hard outcomes of patients with OSA and resistant hypertension warrants further investigation.

Cardiovascular and renal complications in patients with resistant hypertension

With an increased prevalence, resistant hypertension is recognized as an entity with a high cardiovascular morbidity and mortality. In a large cohort of patients with resistant hypertension, the crude incidence rate of total cardiovascular events reached 4.32 per 100 patient-years of follow-up (19.6 %), with a cardiovascular mortality of 8.3 % (incidence rate of 1.72 per 100 patient-years). Cardiovascular event rates are significantly higher in resistant hypertensives compared with non-resistant (18.0 % versus 13.5 %). In the same way, the prevalence of established cardiovascular and renal disease, as the asymptomatic organ damage (represented by left ventricular hypertrophy, carotid wall thickening, arterial stiffness, and microalbuminuria) is higher in these patients. Many studies have demonstrated a strong association between damage to these organs with higher blood pressure levels, the diagnosis of true resistant hypertension, and refractory hypertension. All efforts should be employed in order to control blood pressure and also to regress and/or prevent subclinical cardiovascular and renal damage. The focus should be on prevention of cardiovascular and renal complications, improving the prognosis of resistant hypertension.

Coronary heart disease risk factors and outcomes in the twenty-first century: findings from the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

REasons for Geographic and Racial Differences in Stroke (REGARDS) is a longitudinal study supported by the National Institutes of Health to determine the disparities in stroke-related mortality across USA. REGARDS has published a body of work designed to understand the disparities in prevalence, awareness, treatment, and control of coronary heart disease (CHD) and its risk factors in a biracial national cohort. REGARDS has focused on racial and geographical disparities in the quality and access to health care, the influence of lack of medical insurance, and has attempted to contrast current guidelines in lipid lowering for secondary prevention in a nationwide cohort. It has described CHD risk from nontraditional risk factors such as chronic kidney disease, atrial fibrillation, and inflammation (i.e., high-sensitivity C-reactive protein) and has also assessed the role of depression, psychosocial, environmental, and lifestyle factors in CHD risk with emphasis on risk factor modification and ideal lifestyle factors. REGARDS has examined the utility of various methodologies, e.g., the process of medical record adjudication, proxy-based cause of death, and use of claim-based algorithms to determine CHD risk. Some valuable insight into less well-studied concepts such as the reliability of current troponin assays to identify "microsize infarcts," caregiving stress, and CHD, heart failure, and cognitive decline have also emerged. In this review, we discuss some of the most important findings from REGARDS in the context of the existing literature in an effort to identify gaps and directions for further research.

Atrial fibrillation and incident end-stage renal disease: The REasons for Geographic And Racial Differences in Stroke (REGARDS) study

INTRODUCTION

Atrial fibrillation (AF) is an independent risk factor for end-stage renal disease (ESRD) among persons with chronic kidney disease (CKD), however, the association between AF and incident ESRD has not been examined in the general United States population.

METHODS

A total of 24,953 participants (mean age 65 ± 9.0 years; 54% women; 40% blacks) from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were included in this analysis. AF was identified at baseline (2003-2007) from electrocardiogram data and self-reported history. Incident cases of ESRD were identified through linkage with the United States Renal Data System. Cox proportional-hazards regression was used to compute hazard ratios (HR) and 95% confidence intervals (CI) for the association between AF and incident ESRD.

RESULTS

A total of 2,155 (8.6%) participants had AF at baseline. Over a median follow-up of 7.4 years, 295 (1.2%) persons developed ESRD. In a model adjusted for demographics and potential confounders, AF was associated with an increased risk of incident ESRD (HR=1.51, 95% CI=1.08, 2.11). The association between AF and ESRD became non-significant after further adjustment for CKD markers (eGFR <60 mL/min/1.73 m(2) and urine albumin-to-creatinine ratio ≥ 30 mg/dL) (HR=1.24, 95% CI=0.89, 1.73).

CONCLUSION

AF is associated with an increased risk of ESRD in the general United States population and this association potentially is explained by underlying CKD.

Apparent treatment-resistant hypertension and chronic kidney disease: another cardiovascular-renal syndrome?

To identify patients at increased risk of cardiovascular (CV) outcomes, apparent treatment-resistant hypertension (aTRH) is defined as having a blood pressure above goal despite the use of 3 or more antihypertensive therapies of different classes at maximally tolerated doses, ideally including a diuretic. Recent epidemiologic studies in selected populations estimated the prevalence of aTRH as 10% to 15% among patients with hypertension and that aTRH is associated with elevated risk of CV and renal outcomes. Additionally, aTRH and CKD are associated. Although the pathogenesis of aTRH is multifactorial, the kidney is believed to play a significant role. Increased volume expansion, aldosterone concentration, mineralocorticoid receptor activity, arterial stiffness, and sympathetic nervous system activity are central to the pathogenesis of aTRH and are targets of therapies. Although diuretics form the basis of therapy in aTRH, pathophysiologic and clinical data suggest an important role for aldosterone antagonism. Interventional techniques, such as renal denervation and carotid baroreceptor activation, modulate the sympathetic nervous system and are currently in phase III trials for the treatment of aTRH. These technologies are as yet unproven and have not been investigated in relationship to CV outcomes or in patients with CKD.