Drug therapy for hypertension in hemodialysis patients

The majority of end-stage renal disease (ESRD) patients are hypertensive. Drug therapy for hypertension in hemodialysis (HD) patients includes all classes of antihypertensive drugs, with the sole exception of diuretics. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers may decrease morbidity and mortality by reducing the mean arterial pressure (MAP), aortic pulse wave velocity, and aortic systolic pressure augmentation, as well as left ventricular hypertrophy (LVH) and probably reduction of C-reactive protein (CRP) and oxidant stress. Potential risk factors include hyperkalemia, anaphylactoid reaction with AN69 membranes (particularly ACE inhibitors), and aggravation of renal anemia. beta-blockers decrease not only mortality, blood pressure (BP), and ventricular arrhythmias, but also improve left ventricular function in ESRD patients. Nonselective beta-blockers can cause an increase in serum potassium (particularly during fasting or exercise). Lisinopril and atenolol have a predominant renal excretion and therefore a prolonged half life in ESRD patients. Thus thrice-weekly supervised administration of these drugs after HD can enhance BP control. The use of calcium channel blockers is also associated with lower total and cardiovascular-specific mortality in HD patients. Minoxidil is a very potent vasodilator that is generally reserved for dialysis patients with severe hypertension. Hypertensive dialysis patients who are noncompliant with their medications may benefit from transdermal clonidine therapy once a week. The majority of dialysis patients need a combination of several antihypertensive drugs for adequate BP control.     

Regression of left ventricular hypertrophy after conversion to nocturnal hemodialysis

BACKGROUND: Left ventricular hypertrophy (LVH) is an independent risk factor for mortality in the dialysis population. LVH has been attributed to several factors, including hypertension, excess extracellular fluid (ECF) volume, anemia and uremia. Nocturnal hemodialysis is a novel renal replacement therapy that appears to improve blood pressure control. METHODS: This observational cohort study assessed the impact on LVH of conversion from conventional hemodialysis (CHD) to nocturnal hemodialysis (NHD). In 28 patients (mean age 44 +/- 7 years) receiving NHD for at least two years (mean duration 3.4 +/- 1.2 years), blood pressure (BP), hemoglobin (Hb), ECF volume (single-frequency bioelectrical impedance) and left ventricular mass index (LVMI) were determined before and after conversion. For comparison, 13 control patients (mean age 52 +/- 15 years) who remained on self-care home CHD for one year or more (mean duration 2.8 +/- 1.8 years) were studied also. Serial measurements of BP, Hb and LVMI were also obtained in this control group. RESULTS: There were no significant differences between the two cohorts with respect to age, use of antihypertensive medications, Hb, BP or LVMI at baseline. After transfer from CHD to NHD, there were significant reductions in systolic, diastolic and pulse pressure (from 145 +/- 20 to 122 +/- 13 mm Hg, P < 0.001; from 84 +/- 15 to 74 +/- 12 mm Hg, P = 0.02; from 61 +/- 12 to 49 +/- 12 mm Hg, P = 0.002, respectively) and LVMI (from 147 +/- 42 to 114 +/- 40 g/m2, P = 0.004). There was also a significant reduction in the number of prescribed antihypertensive medications (from 1.8 to 0.3, P < 0.001) and an increase in Hb in the NHD cohort. Post-dialysis ECF volume did not change. LVMI correlated with systolic blood pressure (r = 0.6, P = 0.001) during nocturnal hemodialysis. There was no relationship between changes in LVMI and changes in BP or Hb. In contrast, there were no changes in BP, Hb or LVMI in the CHD cohort over the same time period. CONCLUSIONS: Reductions in BP with NHD are accompanied by regression of LVH.     

Inadequate diagnosis and therapy of arterial hypertension as causes of left ventricular hypertrophy in uremic dialysis patients

BACKGROUND: Left ventricular hypertrophy (LVH) is highly prevalent in the dialyzed population, possibly because of inadequate diagnosis and therapy of arterial hypertension. The purpose of this study was to ascertain the adequacy of our approach in correctly identifying and treating arterial hypertension in our dialysis center. METHODS: Fifty-five dialyzed uremics were studied by continuous ambulatory blood pressure (BP) monitoring, which started before a single hemodialysis (HD) session, continued for 24 hours after HD ended, and was repeated for 15 minutes before the beginning of the next HD. Clinical pre-HD and post-HD routine BP measurements taken the month preceding BP monitoring were retrieved, and echocardiography was performed. RESULTS: LVH was present in 46 out of 55 patients, and clinical pre-HD arterial hypertension was present in 36 out of 55. There were discrepancies between clinical and monitored BPs, mostly concerning diastolic pre-HD BP since BP readings were lower than monitored BP records (P < 0.0002). Although both clinical and monitored BPs bore strong direct correlations with the left ventricular mass (LVM), the closest correlations were those for monitored BP. Four groups of patients were identified by BP monitoring: group A (N = 14), with persistently normal BP, and group D (N = 13), with persistently supranormal BP levels. There were also two other groups (group B, N = 19; and group C, N = 9), whose BP values were high before HD, normalized after HD, and then increased again either soon after HD (group C) or later on following HD (group B). Monthly averaged clinical pre-HD mean BP values differed significantly among the four groups [91 +/- 10 (SD) mm Hg in group A, 101 +/- 7 in group B, 106 +/- 6 in group C, and 106 +/- 7 in group D; P < 0.0001, analysis of variance], as did their corresponding LVMs [132 +/- 27 g/m2 body surface area (BSA), 156 +/- 26, 201 +/- 51, and 200 +/- 36; P < 0.0001]. There were also differences in dialytic age, which was significantly longer in group A patients (109 +/- 54 months), who also tended to have higher, although not significantly higher, Kt/V(urea) values. No differences, however, were detected among the groups as far as type, dosages, and number of antihypertensive drugs given to each individual patient. CONCLUSIONS: The high prevalence of LVH in the dialysis population might be the result of inadequate diagnosis and therapy of arterial hypertension. Arterial hypertension, in fact, was insufficiently treated in our dialysis center, since patients with varying degrees of severity of both arterial hypertension and LVH were kept on antihypertensive therapy of similar strength. Undertreatment may have resulted from not having recognized and/or from having underestimated the severity of arterial hypertension since some clinical BPs were measured incorrectly. Reluctance to use more aggressive antihypertensive therapy might also result from the deceptive feeling of "normalized" BP that one has following volume unloading with dialysis. This causes both the BP to run out of control between dialyses and LVH to worsen.     

Association between extracellular water, left ventricular mass and hypertension in haemodialysis patients.

BACKGROUND: Hypertension and left ventricular hypertrophy (LVH) are present in the majority of patients undergoing haemodialysis (HD). These two pathologies persist after dialysis onset, and pharmacological therapy is often required for adequate control of blood pressure (BP). Although fluid overload is a determinant of hypertension, clinical assessment of this parameter remains difficult and unsatisfactory. Bioimpedance analysis (BIA) spectroscopy and the relative determination of extracellular water (ECW%) may provide a simple and inexpensive tool for investigating fluid overload. We studied 110 patients on thrice-weekly HD to determine whether ECW body content correlates with hypertension and LVH in this patient population. METHODS: Hypertension was determined according to the WHO criteria (office BP >/= 140/90 and/or the use of antihypertensive therapy). Twenty-four hour BP monitoring and echocardiography were performed on midweek inter-HD days. Blood chemistries, dialysis dose (spKt/V) and bioimpedance were analysed on midweek HD days. RESULTS: Hypertension was present in 74.5% of patients. There were no differences for age, spKt/V, haemoglobin, serum creatinine and residual renal function between normotensive and hypertensive patients. Twenty-four hour systolic BP (SBP), 24 h diastolic BP and 24 h pulse pressure were higher in hypertensive patients, in spite of antihypertensive therapy. LVH was present in 61.8% of patients. BIA revealed that ECW% was increased in LVH+ patients (LVH+ = 47.5 +/- 7.9%, LVH- = 42.4 +/- 6.2%, P = 0.01) and in hypertensive patients compared with normotensives (46.5 +/- 7.7% vs 43 +/- 7.2%, P = 0.02). Dry body weights and inter-HD body weight increases did not differ between hypertensive and normotensive patients nor between patients with or without LVH. ECW was correlated with SBP (r = 0.35, P < 0.01) and with left ventricular mass index (LVMi(g/sqm)) (r = 0.49, P < 0.001). A stepwise multiple linear regression model revealed that LVMi(g/sqm) was significantly correlated with ECW%, SBP and male gender (r = 0.65, P < 0.001). CONCLUSIONS: LVH and hypertension are present in a majority of HD patients and they are closely correlated with one another. We found associations between fluid load, measured by BIA and expressed as ECW, and BP and LVM.     

Should the preservation of residual renal function cost volume overload and its consequence left ventricular hypertrophy in new hemodialysis patients?

BACKGROUND: Left ventricular hypertrophy (LVH) is an important predictor of mortality in dialysis patients. The loss of residual renal function (RRF) appears to occur more rapidly in hemodialysis than continuous ambulatory peritoneal dialysis (CAPD). It is more likely that volume expansion in patients on CAPD may preserve RRF. The aim of this study was to investigate whether there is a cause-effect relationship between volume overload and preserving RRF in new hemodialysis patients. METHODS: Nineteen patients with end-stage renal disease (ESRD) starting hemodialysis therapy were included in the study. At the beginning, their elevated blood pressures (BP) were treated with antihypertensive drugs. Thereafter, until normovolemia and normal BP were obtained, strict volume control was applied. The effects of both treatment modalities on the loss of RRF and LVH were evaluated prospectively. RESULTS: At the initial examination, all of the patients were hypertensive and had markedly increased left ventricular mass index (LVMI). The daily urine production was 1575+/-281 mL. At the end of drug treatment period lasting three months, although BP significantly decreased, daily urine production and LVMI only decreased by 12% and 6%, respectively. At the end of the period in which strict volume control was applied, the body weight significantly decreased (from 60+/-5 to 55+/-8 kg, p<0.0001). This decrease in body weight was accompanied by marked decreases in dilated cardiac chamber size and more importantly daily urine production. At the end of this period, while 7 of 19 patients had no residual urine production, residual urine production was below 200 mL/d in the remaining 12 patients. Although the period of volume control was short, there was significant reduction in the LVMI (decreased from 251+/-59 to 161+/-25 gr/m2, p<0.0001). CONCLUSION: The results of our prospective study have clearly shown that the persistence of residual renal function in patients with ESRD starting hemodialysis therapy may largely depend on volume overload. Equally interesting was the finding that despite significantly reduced BP level with hypotensive drugs, there was no marked regression in LVMI. In the contrary, after the volume control period, LVMI was significantly decreased. Our results support the hypotheses that decrease in volume may be more important than pressure reduction in regressing the left ventricular hypertrophy.     

Severe left ventricular hypertrophy in pediatric dialysis: prevalence and predictors

Left ventricular hypertrophy (LVH) has been recognized as an independent risk factor for cardiovascular morbidity and mortality in adults with end-stage renal disease. However, the prevalence and severity of LVH in children on chronic dialysis therapy is not well established. Retrospectively, 64 chronic dialysis patients, aged 20 months to 22 years, on chronic dialysis had echocardiographic evaluation of LV mass (LVM) and geometry. Forty-eight (75%) children had LVH, including 22 of 26 (85%) on hemodialysis (HD) and 26 of 38 (68%) on peritoneal dialysis (PD). The prevalence of LVH in patients on HD was significantly higher than those on PD (P=0.02). Abnormal LV geometry was found in 51 of 64 (80%) patients: 25 patients (39%) had eccentric hypertrophy, 3 (5%) had concentric remodelling, and 23 (36%) had concentric LVH. Twenty-six children (41%) had severe LVH, defined as LVM index greater than 51 g/m2.7, which is associated with a fourfold greater risk for development of cardiovascular disease in adults. Patients with severe LVH had a significantly lower hemoglobin level (P=0.027) and longer duration of renal disease prior to the start of dialysis therapy (P=0.003) than patients without LVH. Multiple logistic regression analysis revealed HD as opposed to PD as a significant independent predictor for severe LVH (P=0.036). Higher systolic blood pressure remained in the final model as an independent predictor with a borderline level of significance (P=0.065). The results indicate that severe LVH and abnormal left ventricular geometry are common in young dialysis patients. Better control of blood pressure, anemia, and hypervolemia may be important in prevention or improving LVH.     

Impact of amlodipine or ramipril treatment on left ventricular mass and carotid intima-media thickness in nondiabetic hemodialysis patients

Objective: Left ventricular hypertrophy (LVH) and atherosclerosis are frequently observed in uremic patients and they have appeared as an independent predictor of cardiovascular morbidity and mortality. The aim of this study was to compare the effects of ramipril and amlodipine on left ventricular mass index (LVMI) and carotid intima-media thickness (CIMT) in nondiabetic hypertensive hemodialysis patients. Methods: A total of 112 hemodialysis (HD) patients were included in this study. Patients were randomly allocated to receive ramipril or amlodipine for 1 year. Blood pressure (BP) measurements, LVMI, and CIMT were assessed at baseline and 6-month intervals. Biochemical parameters and inflammatory markers were also determined at the initiation and during the study period. Results: Similar BP decrease was observed in treatment groups. During follow-up, LVMI and CIMT progressed likewise in both treatment groups despite BP control. However, subgrouping analyses due to the pattern of left ventricular geometry showed that LVMI in patients with eccentric LVH increased, whereas LVMI decreased in subjects with concentric LVH under antihypertensive treatment. Discussion: BP control with ramipril or amlodipine could not provide adequate protection for development or progression of atherosclerosis and eccentric type of LVH in nondiabetic HD patients.     

Changes in left ventricular mass in children and adolescents during chronic dialysis

Left ventricular hypertrophy (LVH) is an independent risk factor for cardiac mortality in adults with end-stage renal disease (ESRD). It is prevalent in pediatric patients on chronic dialysis. The objectives of this study were to evaluate left ventricular mass (LVM) in children and adolescents at the initiation of dialysis and to assess its changes during chronic dialysis therapy. In this longitudinal analysis, 29 patients aged 4–18 years had an echocardiographic evaluation within 90 days of starting dialysis therapy and a follow-up study at least 6 months later. LVH was defined as LVM index (g/m^2.7) >95th percentile for normal children and adolescents. On the initial echocardiogram 20 of 29 (69%) patients had LVH and 24 patients (83%) had abnormal LV geometry (38% eccentric LVH, 31% concentric LVH, and 14% concentric remodelling). Patients with LVH were more likely to be on antihypertensive medications (16/20) than patients without LVH (3/9) (P=0.005). Repeat echocardiogram, performed after 10±3 months on chronic dialysis, showed no significant difference in the mean LVM index (49.6±17.5 g/m^2.7 and 49.7±16.1 g/m^2.7, respectively) or in the prevalence of LVH or LV geometric pattern. However, 14 of 29 patients had a progressive increase in LVM index and 15 patients had regression. Multiple regression analysis showed that baseline LVM index (P=0.005) and interval change in indexed systolic blood pressure (P=0.027) were independent predictors for LVM index changes. In summary, LVH and abnormal LV geometry are already prevalent in children and adolescents with renal failure at the time of initiation of dialysis therapy, indicating that LVH develops during the pre-ESRD course. Early intervention to control blood pressure may be an important factor to improve and prevent progression of LVH in pediatric patients with ESRD. Received: 1 August 2000 / Revised: 5 December 2000 / Accepted: 7 December 2000     

Septic and Aseptic Olecranon Bursitis in Patients on Maintenance Hemodialysis

Background. Left ventricular hypertrophy (LVH) is an important predictor of mortality in dialysis patients. The loss of residual renal function (RRF) appears to occur more rapidly in hemodialysis than continuous ambulatory peritoneal dialysis (CAPD). It is more likely that volume expansion in patients on CAPD may preserve RRF. The aim of this study was to investigate whether there is a cause–effect relationship between volume overload and preserving RRF in new hemodialysis patients. Methods. Nineteen patients with end‐stage renal disease (ESRD) starting hemodialysis therapy were included in the study. At the beginning, their elevated blood pressures (BP) were treated with antihypertensive drugs. Thereafter, until normovolemia and normal BP were obtained, strict volume control was applied. The effects of both treatment modalities on the loss of RRF and LVH were evaluated prospectively. Results. At the initial examination, all of the patients were hypertensive and had markedly increased left ventricular mass index (LVMI). The daily urine production was 1575 ± 281 mL. At the end of drug treatment period lasting three months, although BP significantly decreased, daily urine production and LVMI only decreased by 12% and 6%, respectively. At the end of the period in which strict volume control was applied, the body weight significantly decreased (from 60 ± 5 to 55 ± 8 kg, p < 0.0001). This decrease in body weight was accompanied by marked decreases in dilated cardiac chamber size and more importantly daily urine production. At the end of this period, while 7 of 19 patients had no residual urine production, residual urine production was below 200 mL/d in the remaining 12 patients. Although the period of volume control was short, there was significant reduction in the LVMI (decreased from 251 ± 59 to 161 ± 25 gr/m², p < 0.0001). Conclusion. The results of our prospective study have clearly shown that the persistence of residual renal function in patients with ESRD starting hemodialysis therapy may largely depend on volume overload. Equally interesting was the finding that despite significantly reduced BP level with hypotensive drugs, there was no marked regression in LVMI. In the contrary, after the volume control period, LVMI was significantly decreased. Our results support the hypotheses that decrease in volume may be more important than pressure reduction in regressing the left ventricular hypertrophy.     

Strategies and feasibility of hypertension control in a prevalent hemodialysis cohort

BACKGROUND: There are few data to demonstrate the feasibility of long-term blood pressure (BP) control using short dialysis sessions as practiced in the US. Control of hypertension in hemodialysis patients may reduce the risk of cardiovascular events. METHODS: Forty-two dialysis patients had BPs and weights recorded before and after dialysis for two consecutive weeks and were followed by one physician over three years. Patients were treated by ultrafiltration and conventional antihypertensive drugs and BPs were repeated at three years in the 32 survivors. RESULTS: 93% of the patients (39/42) were African-American. At inception, 85% of the patients were hypertensive with BPs of 154 +/- 23/83 +/- 14 mmHg and 137 +/- 22/74 +/- 14 mmHg pre- and post-dialysis, respectively. The response to ultrafiltration was dependent upon gender, with women having a greater BP reduction compared to men. At three-year follow-up, the BP had dropped significantly in the survivors a mean of 9.4/6.7 mmHg. Pre- and post-dialysis weights, post dialysis BP and interdialytic weight-gain were unchanged. The BP reduction was achieved by an increase in the number of antihypertensive medications from 0.91 +/- 0.86 medications to 1.41 +/- 1.16. Improved BP control did not worsen the efficiency of dialysis (Kt/V). The use of beta-blockers doubled during the period of follow-up. Compared to the USRDS average cardiovascular death rate, the risk of cardiovascular deaths was improved 80% over three years. CONCLUSION: Long-term BP reduction can be achieved through the use of antihypertensive agents and volume control in a predominantly African-American hemodialysis population. This may impact cardiovascular mortality.     

Uncertainties in BP management in dialysis patients

Hypertension in dialysis patients is extremely common. In this article, we review the current evidence for blood pressure (BP) goals in hemodialysis patients, and consider the effectiveness of interventions by which BP may be lowered, including manipulation of dietary and dialysate sodium; optimization of extracellular water; prolongation of dialysis time; and antihypertensive medication. Although two meta-analyses suggest lowering BP using antihypertensive drugs might be beneficial in reducing cardiovascular events and mortality, there are insufficient rigorously designed trials in hypertensive hemodialysis populations to determine preferred antihypertensive drug classes. We suggest aiming for predialysis systolic BP between 130 and 159 mm Hg, while at the same time acknowledge the significant limitations of the data upon which it is based. We conclude by summarizing current knowledge as regards management of hypertension in the peritoneal dialysis population and make recommendations for future research in this field.     

Body fluid spaces and blood pressure in hemodialysis patients during amelioration of anemia with erythropoietin

Blood pressure (BP) may increase in hemodialysis patients during treatment of anemia with recombinant human erythropoietin (r-HuEPO). Since fluid volume is a determinant of BP in dialysis patients, changes in body fluid spaces during r-HuEPO therapy could affect BP. Thus, 51Cr-labeled red blood cell (RBC) volume, inulin extracellular fluid (ECF) volume, and urea total body water (TBW), as well as cardiac output, plasma renin activity (PRA), and plasma aldosterone concentration were determined postdialysis before and after r-HuEPO therapy in patients in whom changes in BP could be managed by ultrafiltration alone. Eleven patients entered the study: one had a renal transplant and two required addition of antihypertensive drug therapy and were excluded; eight, of whom two required antihypertensive drug therapy following the study, were included in the analyses. Results revealed an increase in predialysis hemoglobin from 67 to 113 g/L (6.7 to 11.3 g/dL) (P = 0.001) during 18 +/- 6 weeks of therapy. Predialysis diastolic BP increased from 80 to 85 mm Hg (P = 0.07), while postdialysis diastolic BP was unchanged at 73 mm Hg. 51Cr-RBC volume increased, from 0.7 to 1.3 L (P = 0.004). ECF tended to decrease, from 13.7 to 10.8 L (P = 0.064), while TBW decreased to a similar extent, but not significantly, 34.3 to 31.2 L (P = 0.16). Postdialysis ECF volume was positively correlated with mean arterial BP at baseline (r = 0.89, P = 0.007) and after therapy (r = 0.74, P = 0.035). However, the regression lines for this relationship were different (P = 0.022) before and after therapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

血液透析患者左心室肥厚相关因素分析

目的探讨血液透析患者左心室肥厚(LVH)发生情况及相关危险因素。 方法横断面调查选取江苏大学附属医院血液净化中心维持性血液透析(MHD)患者84例,采集一般情况、生化指标和同期心脏彩色多普勒超声检查结果,按左室心肌质量指数(LVMI)分为左室肥厚组(n＝50)和左室正常组(n＝34),比较两组相关指标的差异。应用Spearman秩相关和多元线性回归分析评价影响左室肥厚的危险因素。 结果左室肥厚组尿素清除指数(Kt/V)、血红蛋白、透析龄均低于正常组,收缩压高于左室正常组,差异有统计学意义(P<0.05)。Spearman秩相关提示LVMI与尿素清除指数(Kt /V)呈负相关(r＝－0.342,P<0.05),与超滤量、收缩压呈正相关(r ＝0.291、0.256,P<0.05)。多元线性回归分析提示Kt /V、收缩压、超滤量与血液透析患者左室肥厚相关(P<0.05)。 结论Kt /V是左室肥厚的保护因素,高收缩压、高超滤量是透析患者左室肥厚的独立危险因素。提高透析充分性,控制收缩压及透析间期入液量可能利于减少左室肥厚的发生。     

Systolic and diastolic hypertension among patients on hemodialysis: Musings on volume overload,arterial stiffness,and erythropoietin

Hypertension among patients on hemodialysis is predominantly systolic (either isolated or combined with diastolic hypertension), whereas the scenario of isolated diastolic hypertension is rare and more common in younger patients. Uncontrolled hypertension that persists despite aggressive antihypertensive drug therapy is a reflection of the volume overload that is a prominent mediator of systolic and diastolic BP elevation. Clinical‐trial evidence supports the notion that dry‐weight probing is an effective strategy to improve BP control, even when overt clinical signs and symptoms of volume overload are not present. Accelerated arterial stiffness influences the patterns and rhythms of interdialytic ambulatory BP and is a major determinant of isolated systolic hypertension in hemodialysis. Posthoc analyses of the Hypertension in Hemodialysis patients treated with Atenolol or Lisinopril (HDPAL) trial, however, suggest that arterial stiffness does not make hypertension more resistant to therapy and is unable to predict the treatment‐induced improvement in left ventricular hypertrophy. A combined strategy of sodium restriction, dry‐weight adjustment, and antihypertensive medication use was effective in improving ambulatory BP control regardless of the severity of underlying arteriosclerosis in HDPAL. Other nonvolume‐dependent mechanisms, such as erythropoietin use, appear to be also important contributors and should be taken into consideration, particularly in younger hemodialysis patients with diastolic hypertension. In this article, we explore the role of volume overload, arterial stiffness, and erythropoietin use as causes of systolic vs diastolic hypertension in patients on hemodialysis. We conclude with clinical practice recommendations and with a call for a “volume‐first” approach when managing hemodialysis hypertension.     

血液透析患者血压控制目标与药物选择

高血压是维持性血液透析患者的常见并发症。长期高血压与血液透析患者增加的死亡率密切相关。因此,血液透析患者的降压治疗在整体治疗中占有重要地位。目前血液透析患者高血压治疗的靶目标尚有争议,作者建议降压的靶目标应该个体化。选择合适的透析方式是降压治疗的重要手段,但多数血液透析患者需要服用两种或两种以上不同类别的降压药联合控制血压,合理选择降压药物至关重要。     

Hypertension in chronic hemodialysis patients: current view on pathophysiology and treatment

BACKGROUND: Hypertension accounts for 65 - 85% of patients beginning dialysis, and dialysis alone controls hypertension in over 50% of patients. PATIENT AND METHODS: We have surveyed the status of BP control in 113 hemodialysis patients, 66 men and 47 women, aged 59 +/- 13 years old, with a mean duration on hemodialysis 42 +/- 44 months. The following measurements were recorded: predialysis mean arterial pressure (pre-MAP), post-dialysis MAP (post-MAP), percentage of change in MAP, pre-dialysis weight, post-dialysis weight, fluid removed by ultrafiltration during each dialysis session, interdialytic weight gain and excess weight over the desirable dry weight. RESULTS: Our results showed a hypertension prevalence of 59% (hypertension defined as pre-MAP +/- 110 mmHg). MAP was not different between men and women, and only 4.5% of patients had isolated systolic hypertension. All hypertensive patients were on treatment with antihypertensives. Reduction in post-MAP by > or = 5% (controlled by ultrafiltration) was found in 68.5% of hypertensive and in 87.5% of normotensive patients. Age, primary renal disease, time on dialysis and adequacy of dialysis were not correlated with pre-MAP. Excess volume and interdialytic weight gain were found to correlate with pre-MAP (p = 0.03). Also, the weekly dosage of EPO had a significant correlation with pre-MAP (p = 0.03). No differences were found among four classes of antihypertensive drugs regarding the BP control. Patients with hypertension requiring one drug achieved a significantly (p < 0.05) lower pre-MAP than the group of patients receiving three or more drugs. In conclusion, hemodialysis population shows high prevalence of hypertension, resistant to antihypertensive treatment. CONCLUSION: Current methods of hemodialysis are not effective in controlling BP. This implies that more insight into the role of excess volume and vasomotor systems in the pathogenesis of dialysis hypertension is warranted.     

Nocturnal blood pressure and 24-hour pulse pressure are potent indicators of mortality in hemodialysis patients

BACKGROUND: Cardiovascular (CV) complications are the leading cause of mortality in hemodialysis patients. The role of arterial hypertension on the prognosis of CV in hemodialysis patients is not as clear as in the general population. The purpose of this study was to investigate the prognostic role of ambulatory blood pressure (BP) on CV mortality in treated hypertensive hemodialysis patients. METHODS: Fifty-seven treated hypertensive hemodialysis patients (56.87 +/- 16.22 years, 30 men) were prospectively studied. All patients initially underwent an ambulatory BP monitoring between two dialysis sessions. The outcome event studied was CV death; kidney transplantation and deaths not related to CV disease were censored. RESULTS: The duration of follow-up was 34.4 +/- 20.39 months, during which 10 CV and 8 non-CV fatal events occurred. In the 10 patients who died from CV complications, age, previous CV events, ambulatory systolic BP, ambulatory pulse pressure (PP), and life-long smoking level were significantly higher, and the office diastolic BP was lower at the time of inclusion than in those who did not die from CV complications (N = 47). Based on Cox analysis and after adjustment for age, sex, and previous CV events, a low office diastolic BP [relative risk (RR) 0.49, 95% CI, 0.25 to 0.93, P = 0.03], an elevated 24-hour PP (RR 1.85, 95% CI, 1.28 to 2.65, P = 0.009), and an elevated nocturnal systolic BP (RR 1.41, 95% CI, 1.08 to 1.84, P = 0.01) were predictors of CV mortality (RR associated with a 10 mm Hg increase in BP and in PP). CONCLUSION: This study demonstrates that nocturnal BP and 24-hour PP are independent predictors of CV mortality in treated hypertensive hemodialysis patients. Randomized trials are needed to investigate whether nocturnal BP and 24-hour PP are superior to office BP as targets for antihypertensive therapy in this high-risk group.     

Combined angiotensin-converting enzyme inhibition and receptor blockade associate with increased risk of cardiovascular death in hemodialysis patients

To compare the relative effectiveness of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in reducing cardiovascular mortality in chronic hemodialysis patients, we conducted an observational analysis of all patients initiated on ACEI or ARB therapy undergoing chronic hemodialysis at a large dialysis provider. Survival curves with mortality hazard ratios (HRs) were generated using the Kaplan-Meier method and Cox regression. Outcomes were compared using inverse probability of treatment weighting and propensity score matching. Over 6 years, 22,800 patients were newly initiated on an ACEI and 5828 on an ARB after at least 60 days of chronic hemodialysis. After adjustment for baseline cardiovascular risk factors, there was no significant difference in the risk of cardiovascular, all-cause, or cerebrovascular mortality in patients initiated on an ARB compared with an ACEI (HR of 0.96). A third of 28,628 patients, newly started on an ACEI or ARB, went on to another antihypertensive medication in succession. After adjustment for risk factors, 701 patients initiated on combined ACEI and ARB therapy (HR of 1.45) or 6866 patients on ACEI and non-ARB antihypertensive agent (HR of 1.27) were at increased risk of cardiovascular death compared with 1758 patients initiated on an ARB and non-ACEI antihypertensive therapy. Thus, an ARB, in combination with another antihypertensive medication (but not an ACEI), may have a beneficial effect on cardiovascular mortality. As observational studies may be confounded by indication, even when adjusted, randomized clinical trials are needed to confirm these findings.     

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.