Drug therapy for hypertension in hemodialysis patients

Diagnosis and treatment of hypertension in dialysis patients: a systematic review

In patients with end-stage renal disease (ESRD) undergoing dialysis, hypertension is common but often inadequately controlled. The prevalence of hypertension varies widely among studies because of differences in the definition of hypertension and the methods of used to measure blood pressure (BP), i.e., peri-dialysis or ambulatory BP monitoring (ABPM). Recently, ABPM has become the gold standard for diagnosing hypertension in dialysis patients. Home BP monitoring can also be a good alternative to ABPM, emphasizing BP measurement outside the hemodialysis (HD) unit. One thing for sure is pre- and post-dialysis BP measurements should not be used alone to diagnose and manage hypertension in dialysis patients. The exact target of BP and the relationship between BP and all-cause mortality or cause-specific mortality are unclear in this population. Many observational studies with HD cohorts have almost universally reported a U-shaped or even an L-shaped association between BP and all-cause mortality, but most of these data are based on the BP measured in HD units. Some data with ABPM have shown a linear association between BP and mortality even in HD patients, similar to the general population. Supporting this, the results of meta-analysis have shown a clear benefit of BP reduction in HD patients. Therefore, further research is needed to determine the optimal target BP in the dialysis population, and for now, an individualized approach is appropriate, with particular emphasis on avoiding excessively low BP. Maintaining euvolemia is of paramount importance for BP control in dialysis patients. Patient heterogeneity and the lack of comparative evidence preclude the recommendation of one class of medication over another for all patients. Recently, however, β-blockers could be considered as a first-line therapy in dialysis patients, as they can reduce sympathetic overactivity and left ventricular hypertrophy, which contribute to the high incidence of arrhythmias and sudden cardiac death. Several studies with mineralocorticoid receptor antagonists have also reported promising results in reducing mortality in dialysis patients. However, safety issues such as hyperkalemia or hypotension should be further evaluated before their use.

Blood Pressure Control and Antihypertensive Treatment among Hemodialysis Patients-Retrospective Single Center Experience

Background and Objectives: Hypertension affects at least 80% of hemodialysis patients. Inappropriate control of blood pressure is mentioned as one of the essential cardiovascular risk factors associated with development of cardiovascular events in dialysis populations. The aim of the cross-sectional, retrospective study was the evaluation of the antihypertensive treatment schedule and control of blood pressure in relation to the guidelines in the group of hemodialysis patients. Additionally, we assessed the level of decrease in blood pressure by each group of hypotensive agents. Materials and Methods: 222 patients hemodialyzed in a single Dialysis Unit in three distinct periods of time—2006, 2011, and 2016—with a diagnosis of hypertension were enrolled in the study. The analysis of the antihypertensive treatment was based on the medical files and it consisted of a comparison of the mean blood pressure results reported during the six consecutive hemodialysis sessions. Results: The mean values of blood pressure before hemodialysis were as follows: 134/77, 130/74, and 140/76 mmHg, after hemodialysis 124/74, 126/73, and 139/77 mmHg in 2006, 2011, and 2016 respectively. The goal of predialysis blood pressure control (<140/90) was achieved by up to 64.3% of participants in 2006 as compared to 49.4% in 2016. Additionally, the postdialysis goal (<130/90) reached 57.1% of the study population in 2006 as compared to 27.1% of patients in 2016. The differences in percentage of patients using single, double, triple, and multidrug therapy during observation were not statistically significant. The most often used drugs were ß-blockers, diuretics, and calcium channel blockers in all points of the study. Blockades of the renin–angiotensin–aldosterone system in 2006 and calcium channel blockers in 2011 and 2016 were the drugs with highest impact on lowering blood pressure. Conclusions: The goal of predialysis or postdialysis blood pressure control was achieved in a lower percentage of patients during the period of the study. Blockade of renin–angiotensin–aldosterone system and calcium channel blockers decrease the blood pressure significantly. It is necessary to achieve better control of blood pressure in prevention of cardiovascular incidents.

Timing of blood pressure medications and intradialytic hypotension

Intradialytic hypotension (IDH) is a prevalent yet serious complication of hemodialysis, associated with decreased quality of life, inadequate dialysis, vascular access thrombosis, global hypoperfusion, and increased cardiovascular and all-cause mortality. Current guidelines recommend antihypertensive medications be given at night and held the morning of dialysis for affected patients. Despite little evidence to support this recommendation, more than half of patients on dialysis may employ some form of this method. In this article, we will review the available evidence and clinical considerations regarding timing of blood pressure medications and occurrence of IDH, and conclude that witholding BP medications before hemodialysis should not be a routine practice.

Prevalence and Hypertension Treatment Schedule in Hemodialysis Patients and Renal Transplant Recipients in 2006 and 2014/2016

BACKGROUND

Hypertension is often recognized in both hemodialysis patients (HDp) and renal transplant recipients (RTRs). The aim of the study was the evaluation of hypertension prevalence and treatment schedule and the achievement of the control of blood pressure according to the Polish Society of Hypertension, European Society of Hypertension, Joint National Committee, and American College of Cardiology/American Heart Association 2017 recommendations.

MATERIALS AND METHODS

Observations were done in 2 distinct periods of time: the year 2006 and the years 2014/2016. In 2006, 56 HDp and 316 RTRs were studied. In 2014/2016, 85 HDp and 818 RTRs were studied. The antihypertensive treatment analysis was based on medical records from visits in RTRs and dialyses in HDp.

RESULTS

Cardiovascular diseases were diagnosed in 71.4% (2006) and 65.9% (2016) in HDp; 17.7% (2006) and 21.5% (2014) in RTRs. Diabetes was observed in 39.3% (2006) and 34.1% (2016) in HDp; 16.5% (2006) and 23.2% (2014) in RTRs. The target blood pressure control was achieved in 64.3% (2006) and 49.4% (2016) of HDp and in 61.4% (2006) and 45.7% (2014) of RTRs. Three drugs (28.6% and 33.5% in 2006; 30.6% and 29.1% in 2016/2014) or 2 antihypertensive drugs (19.6% and 26.9% in 2006; 22.4% and 27.1% in 2016/2014) were used in HDp and RTRs, respectively. The majority of HDp and RTRs were treated with ß-blockers followed by calcium channel blockers.

CONCLUSIONS

The target blood pressure control was achieved in a low percentage of HDp and RTRs. RTRs required multidrug antihypertensive therapy to control blood pressure more often than HDp.

High blood pressure in dialysis patients: cause, pathophysiology, influence on morbidity, mortality and management

Dialysis is initiated in a patient with End stage renal disease. The recent guidelines suggest the initiation of dialysis when symptoms and signs of kidney failure are present and not merely a decrease in GFR. The most common complication postdialysis is the occurrence of hypotension. However many dialysis patients are found to be hypertensive. In this article, we mention the cause and pathophysiology of hypertension in dialysis patients and its management.

Assessment and management of hypertension in patients on dialysis

Hypertension is common, difficult to diagnose, and poorly controlled among patients with ESRD. However, controversy surrounds the diagnosis and treatment of hypertension. Here, we describe the diagnosis, epidemiology, and management of hypertension in dialysis patients, and examine the data sparking debate over appropriate methods for diagnosing and treating hypertension. Furthermore, we consider the issues uniquely related to hypertension in pediatric dialysis patients. Future clinical trials designed to clarify the controversial results discussed here should lead to the implementation of diagnostic and therapeutic techniques that improve long-term cardiovascular outcomes in patients with ESRD.

Potassium balance in dialysis patients

The advent of dialytic therapy has enabled nephrologists to provide life-saving therapy, but potassium balance continues to be an ever present challenge in the ESRD population. Although a small percent of patients are chronically hypokalemic, hyperkalemia is by far the most common abnormality in dialysis patients. It is associated with increased all-cause mortality, cardiovascular mortality, and arrhythmogenic death. Although alterations of the dialysis bath may decrease predialysis potassium, potassium baths <2 mEq/l are associated with a higher risk of sudden cardiac death. Studies show that patients are aware of the risks of hyperkalemia, but adherence to a low potassium diet is suboptimal. ACEI, ARBs, and spironolactone may cause slight increases in potassium even in anuric patients, requiring increased surveillance. Fludrocortisone and potassium binders have not been proven to be beneficial in lowering interdialytic potassium levels. Frequent hemodialysis may be a viable option, and studies of prophylactic placement of implantable cardioverter/defibrillators are underway.

Lisinopril pharmacokinetics and erythropoietin requirement in haemodialysis patients

BACKGROUND

There is ongoing controversy whether angiotensin-converting enzyme inhibitors (ACE-I) contribute to anaemia by causing hyporesponsiveness to erythropoiesis-stimulating agents (ESA). However, it is unknown whether or not plasma levels or area under the curve (AUC) of ACE-I are associated with responsiveness to ESA therapy.

MATERIALS AND METHODS

We examined the association between lisinopril AUC, lisinopril plasma levels and ESA requirements that was assessed using an ESA index [(ESA IU/week/body weight kg)/(haemoglobin g/dL)]. After screening 184 haemodialysis patients, 14 fulfilled the inclusion criteria, mainly long-term use of oral lisinopril in the upper end of dosage range for this population with stable haemoglobin levels and intravenous ESA therapy. Lisinopril plasma levels were measured at eight different time points (predialysis, immediate post-dialysis and hourly for 6h thereafter; AUC1), and the seven post-dialysis lisinopril plasma levels were used for calculation of AUC2.

RESULTS

The mean ESA index of all patients was 27·90±25·84 (IU/week/kg)/(g/dL). Average lisinopril AUC1 was 1212·48±1209·75 [mg*h/L], whereas AUC2 averaged 947·67±977·07 [mg*h/L]. Two patients (14%) had no detectable lisinopril plasma levels, indicating their noncompliance. There was no association between ESA index and AUC or plasma levels of lisinopril at any time point for all 14 or for the 12 compliant patients.

CONCLUSIONS

Our study shows that long-term, high-dose lisinopril therapy has no effect on ESA responsiveness. Thus, avoidance or a dose reduction of ACE-I in dialysis patients will not necessarily lead to reduced ESA requirements and costs.

Management of Hypertension in Renal Transplant Patients: A Comprehensive Review of Nonpharmacologic and Pharmacologic Treatment Strategies

Objective:

To review the guidelines and literature for the treatment of hypertension in renal transplant patients and to provide guidance to practitioners in the selection of appropriate nonpharmacologic and pharmacologic treatment options.

Data Sources:

A PubMed search (January 1948–March 2010) was performed using the search terms hypertension, antihypertensive agents, blood pressure, and cardiovascular disease, in combination with renal transplant and kidney transplant. The search was limited to articles published in English. All relevant peer-reviewed original studies, meta-analyses, guidelines, consensus statements, and review articles were examined. In addition, reference citations from publications identified were reviewed.

Study Selection and Data Extraction:

All literature found was evaluated for inclusion. Review articles as well as prospective and retrospective original research articles were reviewed.

Data Synthesis:

Hypertension after solid organ transplantation is a problem commonly encountered in patients during their posttransplantation clinic visits. Effective management of these patients' hypertension is crucial, as hypertension left untreated may lead to increased morbidity and mortality as well as graft loss. The unique, multifactorial etiology of hypertension in this population makes treatment choices more challenging compared to treatment of a nontransplant patient. Therefore, to guide practitioners in this process, we developed a hypertension management protocol, taking into account the unique considerations faced in the adult renal transplant population. The review guides practitioners from the initial assessment of patients' hypertension through the evaluation and selection of nonpharmacologic and pharmacologic treatment options and provides information about the discontinuation of certain antihypertensive medications. It also provides a concise, but comprehensive review of the major antihypertensive drug classes and economic considerations.

Conclusions:

The management of hypertension in posttransplantation patients is challenging and complicated, yet necessary to prevent morbidity, mortality, and graft loss for these patients. Therapy should be individualized based on patient assessment, response to previous therapy, and economic considerations.

[Drug treatment of hypertension in hemodialysed patients]

A fraction of the dialyzed patients remains hypertensive despite achievement of the "dry weight" and will eventually require a pharmacological antihypertensive treatment. There is only scarce randomized intervention trials available in those patients so it is difficult to estimate whether the cardiovascular benefit of the treatment is related to blood pressure lowering per se or to class or drug specific properties. This paper reviews the different class of antihypertensive drugs focusing on their advantages and disadvantages in dialysis patients. On a practical ground, prescription will be driven by pharmacokinetics considerations and mostly according to specific indications pertinent to cardiovascular complications associated with hypertension.

On the importance of pedal edema in hemodialysis patients

BACKGROUND AND OBJECTIVES

Volume control is a key component of treatment of hemodialysis patients. The role of pedal edema as a marker of volume is unknown. The objective of this study was to determine factors that are associated with edema.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cross-sectional study of asymptomatic hemodialysis patients (n = 146) in four university-affiliated hemodialysis units was conducted. Echocardiographic variables, blood volume monitoring, plasma volume markers (plasma renin and aldosterone and N-terminal pro B-type natriuretic peptide), and inflammation markers (C-reactive protein and IL-6) were measured as exposures, and edema was measured as outcome.

RESULTS

In a multivariate logistic regression analysis, age, body mass index, and left ventricular hypertrophy were independent determinants of edema. Compared with patients with normal or low weight, overweight patients had odds ratio for edema of 5.7 (95% confidence interval [CI] 1.0 to 31.8), and obese patients of 44.8 (95% CI 9.0 to 223). Patients in the top quartile of left ventricular mass index and normal to low weight had odds ratio of edema of 7.7 (95% CI 2.3 -25.9), those who were overweight of 43.5 (95% CI 3.9 to 479.8), and those who were obese of 344.8 (95% CI 33.8 to 3515). Inferior vena cava diameter, blood volume monitoring, plasma volume markers, and inflammation markers were not determinants of edema.

CONCLUSIONS

Pedal edema correlates with cardiovascular risk factors such as age, body mass index, and left ventricular mass but does not reflect volume in hemodialysis patients.

β-Blockers improve outcomes in kidney disease patients having noncardiac vascular surgery

Beta-blockers are known to improve postoperative outcome after major vascular surgery. We studied the effects of beta-blockers in 2126 vascular surgery patients with and without kidney disease followed for 14 years. Creatinine clearance was calculated using the Cockcroft-Gault equation, and kidney function was categorized as Stage 1 for a reference group of 550 patients, Stage 2 with 808 patients, Stage 3 with 627 patients, and combined Stages 4 and 5 with 141 patients. Outcome measures were 30-day and long-term all-cause mortality with a mean follow-up of 6 years. Cox proportional hazards models were used to control cardiovascular risk factors, including propensity for beta-blocker use. In all, 129 (6%) and 1190 (56%) patients died respectively. Mortality rates were three- and two-fold higher, respectively, for patients at Stages 3-5 compared to the reference group for the two outcomes. beta-Blocker use was significantly associated with a lower risk of mortality after surgery. The overall adjusted hazard ratio was 0.35 and 0.62, respectively, for individuals at Stages 3-5 compared to the reference group for 30-day and long-term mortality. This study shows that kidney function is a predictor of all-cause mortality and beta-blocker use is associated with a lower risk of death in kidney disease patients undergoing elective vascular surgery.

Management of hyperkalemia in dialysis patients

Hyperkalemia is common in patients with end-stage renal disease, and may result in serious electrocardiographic abnormalities. Dialysis is the definitive treatment of hyperkalemia in these patients. Intravenous calcium is used to stabilize the myocardium. Intravenous insulin and nebulized albuterol lower serum potassium acutely, by shifting it into the cells. Despite their widespread use, neither intravenous bicarbonate nor cation exchange resins are effective in lowering serum potassium acutely. Prevention of hyperkalemia currently rests largely upon dietary compliance and avoidance of medications that may promote hyperkalemia. Prolonged fasting may provoke hyperkalemia, which can be prevented by administration of intravenous dextrose.

Should β-Blockers Be Used to Control Hypertension in People With Chronic Kidney Disease?

Activation of the sympathetic nervous system is common in patients with chronic kidney disease, plays an important role in the genesis of hypertension, the rate of decrease of renal function, and is associated with the increased cardiovascular morbidity and mortality seen in these patients. beta-blockers are potent antihypertensive agents but differ in their hemodynamic effects on renal function. The cardioselective beta-blockers such as atenolol and metoprolol are known to retard the progression of renal diseases, but to a lesser degree compared with blockers of the renin-angiotensin-aldosterone system. However, the newer vasodilating beta-blockers such as carvedilol and nebivolol have different effects on renal hemodynamics and function primarily because of its greater adjunctive alpha1-blocking activity. Carvedilol decreases renal vascular resistance and prevents reductions in the glomerular filtration rate and renal blood flow in patients with hypertension with or without impaired kidney function. In addition, carvedilol may retard progression of albuminuria, and provide cardiorenal protection in chronic kidney disease patients with hypertension, congestive heart failure, and at high risk for sudden cardiac death.

Restless legs syndrome in hemodialysis patients: association with calcium antagonists. A preliminary report

Uremia-related restless legs syndrome (RLS) is a known form of secondary RLS. This cross-sectional survey included patients (n = 82) on stable hemodialysis (HD; >3 months, Kt/V >1.2) who were iron-replete, free of neurodegenerative or psychiatric disorders, severe polyneuropathy and radiculopathy, not exposed to antipsychotics/antidepressants, and not severely anemic. Forty-nine (60%) were RLS 'positive', and 25 (31%) had severe/very severe symptoms (International Restless Legs Syndrome Study Group criteria). None had been diagnosed previously. In a multivariate analysis, the prevalence of RLS was higher in diabetic patients [vs. nondiabetics; prevalence ratio (PR) 2.32, 95% CI 1.50-3.60, p < 0.001] and those exposed to Ca2+ antagonists (vs. nonexposed; PR 2.02, CI 1.47-2.76, p < 0.001), and also increased with dialysis duration (PR 1.05, 95% CI 1.02-1.09, p < 0.001). Association of Ca2+ antagonists and RLS in uremic patients has not been reported previously and deserves further research.

Beta blockers in the management of chronic kidney disease

The sympathetic nervous system modulates renal function through its receptors namely beta1 (cardiac output and renin release), alpha1 (systemic and renovascular constriction), and beta2 renovascular dilation. Sympathetic overactivity is commonly seen in chronic kidney disease (CKD) and is an important contributor to increasing the risk of cardiovascular events as well as increasing renal disease progression. Recent evaluations of drug use in people with CKD shows a remarkably low percentage of patients receiving beta-blockers, especially in more advanced stage CKD when cardiovascular risk is higher. This is in large part due to tolerability of these agents. Moreover, water-soluble beta-blockers such as atenolol and metoprolol are dialyzable and require supplementation to avoid exacerbation of arrhythmias following dialysis. Newer vasodilating beta-blockers have better tolerability and different effects on renal hemodynamics as well as metabolic variables. These effects are related to the relative alpha1-blocking effect of agents such as carvedilol and labetolol, with carvedilol having relatively greater alpha-blocking effects. Few studies evaluate beta-blockers on cardiovascular risk in CKD patients. Studies with carvedilol demonstrate attenuated increases in albuminuria as well as reduction in cardiovascular events in CKD patients with hypertension. This paper reviews the animal and clinical trial data that evaluate beta-blockers in CKD highlighting the vasodilating beta-blockers. It is apparent that greater use of this drug class for blood pressure control would further enhance reduction of risk of heart failure, the most common cause of death in the first year of starting dialysis.

Effects of imidapril on left ventricular mass in chronic hemodialysis patients

Left ventricular hypertrophy is considered to be a major cardiovascular risk factor in hemodialysis patients. Not only high blood pressure but also humoral factors such as angiotensin II and aldosterone are thought to contribute to the increase in left ventricular mass. We examined the effects of an angiotensin converting enzyme (ACE) inhibitor, imidapril, on left ventricular mass in patients with end-stage renal diseases on maintenance hemodialysis. Thirty patients on chronic hemodialysis were randomly divided into 2 groups of 15 patients each and given placebo or 2.5 mg imidapril once daily for 6 months. Before and after the 6-month period, left ventricular mass was evaluated by echocardiography, and circulating factors of the renin-angiotensin-aldosterone system were measured. Background characteristics such as age, gender ratio, causes of renal failure, duration of hemodialysis, body mass index and pre-dialysis blood pressure were comparable between the placebo and the imidapril groups. Systolic and diastolic blood pressures were not significantly changed in either group during the study period. In the imidapril group, serum ACE was reduced (12 +/- 1 to 5 +/- 2 U/l, p < 0.01) and plasma renin activity was increased (3.3 +/- 0.8 to 8.1 +/- 3.2 ng/ml/h, p < 0.01), but plasma angiotensin II and aldosterone were not significantly changed after 6 months (13 +/- 3 to 17 +/- 3 pg/ml and 365 +/- 125 to 312 +/- 132 pg/ml, respectively). On the other hand, left ventricular mass index was significantly decreased in the imidapril group (132 +/- 10 to 109 +/- 6 g/m2, p < 0.05) but was unchanged in the placebo group (129 +/- 6 to 126 +/- 5 g/m2). These results suggest that an ACE inhibitor reduces left ventricular mass in hemodialysis patients by a mechanism that is independent of changes in blood pressure.

Hypertension in dialysed children: the prevalence and therapeutic approach in Poland--a nationwide survey

BACKGROUND

The aim of this nationwide analysis was to assess the incidence and current treatment profile of arterial hypertension in children undergoing chronic haemodialysis or peritoneal dialysis and attitudes of paediatric nephrologists towards the choice of antihypertensive drugs in their patients.

METHODS

The study group consisted of 134 children (89 males, 45 females, mean age 10.7+/-5 years) from all 13 paediatric dialysis centres in Poland. The data were gathered through a questionnaire for each patient dialysed in November 2004.

RESULTS

The overall incidence of hypertension in the study group was 55% (74 of 134 patients; 47 males, 27 females). The incidence rate was similar in boys and girls (53 vs 60%) and in those on haemodialysis and peritoneal dialysis (56 vs 54%). Chronic glomerulonephritis as an underlying renal disease was significantly more frequent in the hypertensive than in the normotensive subjects (37 vs 10%, P = 0.004). Residual urine output was higher in normotensives (41 vs 10 ml/kg body weight; P < 0.001). Among those treated with antihypertensives: 32% were treated by monotherapy, 36% received two drugs, 22% received three drugs, while 7% received > or = 4 drugs. The therapy was effective in only 57% of subjects. We observed no differences in biochemical and clinical parameters between those who responded to the therapy and those who failed to do so. Calcium channel blockers constituted the most frequently administered class of drugs [73% of children; in 43 out of 48 (90%) combined with other drugs, but in 11 out of 24 (46%) as a monotherapy]. In monotherapy, angiotensin-converting enzyme inhibitors and calcium channel blockers were administered most frequently.

CONCLUSION

We conclude that the incidence of hypertension in dialysis children in Poland is high (55%). The effectiveness of antihypertensive treatment is rather low (58%) and the choice of drugs is limited.

Hypertension in Chronic Kidney Disease and Dialysis: Pathophysiology and Management

Hypertension affects 24% of the adult US population. In the United States, 3% of the adult population has an elevated serum creatinine level, and 70% of these patients have hypertension. The prevalence of hypertension in chronic kidney disease (CKD) depends on the patient's age and the severity of renal failure, proteinuria, and underlying renal disease. As patients with CKD progress to end-stage renal disease (ESRD), 86% are diagnosed with hypertension. It has long been recognized that kidney function affects and is affected by hypertension. This article discusses the pathophysiology and management of hypertension in patients with CKD.

Hypertension and the Kidney

Hypertension is an important and widely prevalent risk factor for the development of chronic kidney disease (CKD), which unfortunately may progress to end-stage renal disease. CKD is a progressive condition that causes significant morbidity and mortality. Diabetes is the leading cause of end-stage renal disease in the Western world. Both hypertension and diabetes are the causative factors for the occurrence of CKD and its consequences. Aggressive control of hypertension and diabetes is indicated to reduce the risk for kidney disease in the community. Certainly, effective control of hypertension is a proven modality to prevent renal disease. The concept of decreasing the systemic blood pressure as well as the intraglomerular pressure has led to the application of rational therapeutic options in patients with renal insufficiency. Although treatment of hypertension alone is critical, drugs that block the renin-angiotensin system have been shown to have special renal (and cardiovascular) benefits. Early detection and treatment of microalbuminuria is an integral part of disease management. This article reviews the pathophysiologic and therapeutic implications of the link between hypertension and the kidney.