Pressor effect of recombinant human erythropoietin: results of ambulatory blood pressure monitoring and home blood pressure measurements

The effect of erythropoiesis-stimulating agents on systolic and diastolic blood pressure in hemodialysis patients: A systematic review and meta-analysis of clinical trials

OBJECTIVE

Anemia is a common condition in end-stage renal disease (ESRD) patients. Erythropoiesis-stimulating agents (ESAs) are commonly used to treat anemia in these patients. However, concerns have been raised regarding their potential effects on blood pressure. This systematic review and meta-analysis aim to investigate the relationship between ESAs and changes in systolic and diastolic blood pressure in hemodialysis patients.

METHOD

This study is a systematic review and meta-analysis based on clinical trial studies published in various databases, including Web of Science, Cochrane Library, Science Direct, PubMed, Embase, Scopus, and Google Scholar, between 1980 and the end of 2022. We evaluated the quality of articles using the Jadad scale checklist and analyzed the data using Stata 15 software.

RESULTS

Our meta-analysis included 34 clinical trial studies. The results showed a significant increase in both systolic blood pressure (SBP) and diastolic blood pressure (DBP) after the consumption of ESAs compared to before consumption. The mean difference in SBP was 4.84mmHg (95% CI: 2.74-6.94; p-value<0.001) and in DBP was 4.69mmHg (95% CI: 2.67-6.71; p-value<0.001). No publication bias was observed. Our meta-regression analysis showed that sample size, quality assessment score, and geographical location of the study were significant factors related to observed heterogenicity in to mean difference of SBP (p-value≤0.20). For DBP, the sample size, quality assessment score and follow-up duration were significant variables (p-value≤0.20).

CONCLUSION

Based on the findings of our study, it appears that receiving ESAs is associated with a significant increase in both SBP and DBP in hemodialysis patients, with an increase of about 5mmHg.

A dosing algorithm for erythropoietin alpha in older adults with heart failure and a preserved ejection fraction

AIMS

Erythropoietin stimulating agents (ESAs) is an active area of clinical investigation in heart failure (HF) but can cause hypertension and higher hemoglobin concentrations (Hb) that have been associated with adverse outcomes. We evaluated a dosing algorithm and potential confounders' effect on Hb and blood pressure (BP) in a clinical trial.

METHODS

In an ongoing randomized, placebo controlled, single blind clinical trial of ESA (epoetin alfa) in anemic patients with HF and a preserved ejection fraction (HFPEF), Hb was measured weekly as was BP, weight and concomitant medical therapy. A repeated measure mixed model evaluated determinants of weekly changes in Hb and BP.

RESULTS

Among 45 subjects (78 ± 11 years, 67% women, EF = 57 ± 9%) with a total of 780 repeated weekly Hb measures, Hb significantly increased over time in those assigned to ESA (β = 0.933, P < 0.0001), compared to placebo. Dose (β = -0.108, P < 0.0001), patient weight (β = -0.016, P = 0.0037), diuretic use (β = -0.124, P = 0.0389), and time (β = 0.003, P = 0.0331), were all significantly associated with Hb change. Increased diuretic dose and weight change were significantly inversely associated with changes in Hb. ESA administration and dose were not significant determinants of absolute BP or changes in BP from baseline.

DISCUSSION

In addition to ESA dose and duration of therapy, factors indicative of volume status including weight and diuretic use are determinants of hemoglobin levels in HF subjects.

CONCLUSION

The currently employed dosing algorithm, which adjusts the administration of ESA based on the absolute hemoglobin and weekly change in hemoglobin increases Hb with relatively a low weekly dose of ESA without significant effects on BP.

Erythropoietin and the cardiorenal syndrome: cellular mechanisms on the cardiorenal connectors

We have recently proposed severe cardiorenal syndrome (SCRS), in which cardiac and renal failure mutually amplify progressive failure of both organs. This frequent pathophysiological condition has an extremely poor prognosis. Interactions between inflammation, the renin-angiotensin system, the balance between the nitric oxide and reactive oxygen species and the sympathetic nervous system form the cardiorenal connectors and are cornerstones in the pathophysiology of SCRS. An absolute deficit of erythropoietin (Epo) and decreased sensitivity to Epo in this syndrome both contribute to the development of anemia, which is more pronounced than renal anemia in the absence of heart failure. Besides expression on erythroid progenitor cells, Epo receptors are present in the heart, kidney, and vascular system, in which activation results in antiapoptosis, proliferation, and possibly antioxidation and anti-inflammation. Interestingly, Epo can improve cardiac and renal function. We have therefore reviewed the literature with respect to Epo and the cardiorenal connectors. Indeed, there are indications that Epo can diminish inflammation, reduce renin-angiotensin system activity, and shift the nitric oxide and reactive oxygen species balance toward nitric oxide. Information about Epo and the sympathetic nervous system is scarce. This analysis underscores the relevance of a further understanding of clinical and cellular mechanisms underlying protective effects of Epo, because this will support better treatment of SCRS.

Management of hypertension in hemodialysis patients

The relationship of hypertension with adverse outcomes is uncertain in the hemodialysis population. If hypertension is an etiologically significant cardiovascular risk factor in hemodialysis patients, the first step would be to assess the level of BP accurately. BP obtained at home over a week and averaged using a validated oscillometric automatic device can prove valuable. To the extent BP lowering influences cardiovascular outcomes, home BP of 150/90 mm Hg would warrant therapy, since it correlates with target organ damage and hypertension diagnosed by ambulatory BP monitoring. To manage hypertension, limiting dietary sodium intake and individualizing dialysate sodium delivery would be first steps. The magnitude of reduction in BP with dietary sodium restriction and the whether dialysate sodium can be safely limited in those who are hypotension-prone is unclear. Antihypertensive drug therapies can effectively reduce BP and are needed by the vast majority of hemodialysis patients. Whether control of hypertension translates into better outcomes is not known, but collective evidence suggests that hypertension should be controlled in hemodialysis patients.

The Effects of Maintenance Recombinant Human Erythropoietin Therapy on Ambulatory Blood Pressure Recordings: Conventional, Doppler, and Tissue Doppler Echocardiographic Parameters

Cardiovascular disease is the major cause of mortality in maintenance hemodialysis patients. Left ventricular dysfunction is present in approximately 80% of these patients and is highly predictive of future ischemic heart disease, cardiac failure, and death. Anemia has been identified as one of several risk factors responsible for cardiac complications. The treatment of renal anemia with recombinant human erythropoietin (rHuEpo) and consequent improvement of cardiac performance may reverse pathological changes in left ventricular geometry. In this study, the acute and chronic effects of rHuEpo administration on 24-hour ambulatory blood pressure recordings and echocardiographic parameters in 30 rHuEpo-naïve maintenance hemodialysis patients were examined. Twenty-four-hour ambulatory blood pressure monitoring was performed prior to and after 1 week and 6 months of rHuEpo administration. The patients underwent echocardiographic examination prior to and after 6 months of rHuEpo administration. One week treatment with rHuEpo did not cause any significant change in 24-hour ambulatory blood pressure recordings. After 6 months of therapy, serum hemoglobin levels increased from 8.8 +/- 0.66 g/dL to 10.8 +/- 0.70 g/dL (P < 0.05). Echocardiographic examination revealed elevation in ejection fraction (62.26 +/- 6.84% vs. 69.90 +/- 8.98%, P < 0.05) with reductions in fractional shortening (36.70 +/- 4.96% vs. 35.96 +/- 6.32%, P < 0.05), interventricular septum thickness (1.21 +/- 0.16 vs. 1.00 +/- 0.16 cm, P < 0.05), and left ventricular mass index (148.2 +/- 46.5 g/m2 vs. 93.6 +/- 17.2 g/m2, P < 0.05). Doppler echocardiography and tissue Doppler imaging provided additional information in comparison with conventional echocardiography. Before treatment, mitral flow E wave (E, 0.64 +/- 0.27 vs. 0.82 +/- 0.17 cm/s), mitral flow A wave (A, 0.80 +/- 0.21 vs. 0.70 +/- 0.21 cm/s), early diastolic velocity of lateral wall (Lateral E', 11.2 +/- 2.8 vs. 12.4 +/- 2.3 cm/s), late diastolic velocity of lateral wall (Lateral A', 6.7 +/- 2.5 vs. 7.8 +/- 2.1 cm/s), early diastolic velocity of septal wall (Septal E', 9.7 +/- 2.9 vs. 11.3 +/- 1.1 cm/s), and late diastolic velocity of septal wall (Septal A', 6.4 +/- 2.1 vs. 7.8 +/- 2.0 cm/s) were significantly lower in patients than in the controls. Patients and controls have similar deceleration time of mitral flow E wave (E Dec, 186 +/- 57.8 vs. 192 +/- 62.4 ms), isovolumic left ventricular relaxation time (IVRT, 111.9 +/- 30.7 vs. 91.1 +/- 32 ms), systolic velocity of lateral wall (Lateral S', 7.8 +/- 2.3 vs. 8.1 +/- 2.0 cm/s), and systolic velocity of septal wall (Septal S', 7.5 +/- 1.9 vs. 7.7 +/- 1.4 cm/s) values. Therapy with rHuEpo did not cause significant changes in E (0.64 +/- 0.27 vs. 0.76 +/- 0.29 cm/s), A (0.80 +/- 0.21 vs. 0.79 +/- 0.23 cm/s), E Dec (186 +/- 57.8 vs. 165.8 +/- 60.1 ms), IVRT (111.9 +/- 30.7 vs. 101.6 +/- 36.2 ms), Lateral E' (11.2 +/- 2.8 vs. 11.5 +/- 4.4 cm/s), Lateral A' (6.7 +/- 2.5 vs. 7.4 +/- 2.1 cm/s), Lateral S' (7.8 +/- 2.3 vs. 8.1 +/- 2.0 cm/s), Septal E' (9.7 +/- 2.9 vs. 10.0 +/- 1.1 cm/s), Septal A' (6.4 +/- 2.1 vs. 6.6 +/- 2.0 cm/s), and Septal S' (7.5 +/- 1.9 vs. 7.9 +/- 1.4 cm/s) indicating persistence of diastolic dysfunction. In 6 months time, 24-hour ambulatory blood pressure recordings, however, tended to be higher (systolic: 125.16 +/- 21.02 mm Hg vs. 134.36 +/- 23.98 mm Hg; diastolic: 77.40 +/- 14.47 mm Hg vs. 83.26 +/- 14.89 mm Hg, P < 0.05). Correction of anemia with rHuEpo results in the elevation of blood pressure and reduction in left ventricular mass index. Myocardial contraction and relaxation velocities did not improve following regression of left ventricular hypertrophy, suggesting the persistance of diastolic dysfunction. Doppler echocardiography with tissue Doppler imaging reflects the real situation of diastolic function in patients on maintenance hemodialysis.

Assessment of blood pressure in hemodialysis patients

It is self-evident that accurate measurement of blood pressure (BP) is essential for the diagnosis and treatment of hypertension. Patients on hemodialysis typically do not have their BP measured under standardized conditions, a source of error in the assessment of their BP. However, their are some unique sources of error involving interdialytic weight gain, occurrence of sleep apnea and consequent nocturnal hypertension, inability to take BP in both arms in patients who have hemodialysis angioaccess in the arm, and the white coat effect in these patients as well. Precise measurement of BP in hemodialysis patients requires interdialytic ambulatory BP monitoring. However, when ambulatory BP monitoring is not possible, BP obtained in the dialysis unit can be used in a qualitative sense for prediction of hypertension in these patients. A 2-week average predialysis BP of greater than 150/85 mmHg or a postdialysis BP of greater than 130/75 mmHg has at least 80% sensitivity in diagnosing hypertension. Specificity of at least 80% can be achieved if predialysis BP of greater than 160/90 mmHg or postdialysis BP of greater than 140/80 mmHg are used. However, poor agreement between hemodialysis unit BP and ambulatory BP precludes their use for the precise prediction of BP. Improving measurement techniques in the dialysis unit, averaging multiple BP values, using 20-minute postdialysis readings, or home BP monitoring can improve BP determination when interdialytic BP monitoring is not possible.

Normalization of hematocrit in hemodialysis patients with cardiac disease does not increase blood pressure

Since the earliest reports of the use of Epoetin alfa in hemodialysis patients, it has been described that Epoetin alfa may exacerbate preexisting hypertension or induce hypertension in End Stage Renal Disease (ESRD) patients not previously hypertensive. We undertook this study to determine if the correction of anemia in ESRD patients with cardiac disease from a hematocrit of 30+/-3% to 42+/-3% with the use of Epoetin alfa would result in increased blood pressure. This study was a substudy of the "Normal hematocrit Study".

METHODS

Thirty-one patients were randomized into one of two arms. Patients in Group A had their hematocrit increased with the use of slowly escalating doses of Epoetin alfa to 42+/-3% and patients in Group B were maintained with a hematocrit of 30+/-3% throughout the course of the study. All patients had their blood pressure recorded with a 24 hour ambulatory BP device at study entry and at 28 weeks following randomization when they had achieved their target hematocrit. Pre-dialysis systolic and diastolic BP was also recorded.

RESULTS

The mean hematocrit increased in Group A from 29.1+/-2.4% to 40.8+/-5.2% after 30 weeks. The hematocrit in Group B remained stable at 30+/-3% throughout the course of the study. There was no difference in mean daytime, mean nighttime or 24 hour systolic or diastolic blood pressure between Groups A and B at either baseline or follow-up. Neither was there a difference in mean pre-dialysis systolic or diastolic BP between Groups A or B at baseline or Follow-up. Four patients in Group A and 4 patients in Group B required an increase in their antihypertensive medication during the course of the study.

CONCLUSION

It is possible to increase hematocrit to normal levels in hemodialysis with the administration of Epoetin alfa. The increase in hematocrit from 30+/-3% to 42+/-3% is not associated with increased blood pressure.

Effects of normal hematocrit on ambulatory blood pressure in epoetin-treated hemodialysis patients with cardiac disease

BACKGROUND

Hypertension is a recognized complication of partial correction of anemia with recombinant human erythropoietin (epoetin) in hemodialysis patients. We used interdialytic ambulatory blood pressure (ABP) monitoring to study the effects of partially corrected anemia versus normal hematocrit (hct) on BP in hemodialysis patients.

METHODS

Repeated interdialytic ABP monitoring was performed for up to one year in 28 chronic hemodialysis patients with cardiac disease who were randomized to achieve and maintain normal hct levels (42 +/- 3%, group A) or anemic hct levels (30 +/- 3%, group B) with epoetin. Routine BP measurements obtained at dialysis treatments were also evaluated.

RESULTS

Mean hct levels were 30.7 +/- 0.7% in group A and 30.6 +/- 0.7% in group B at baseline, then 39.3 +/- 1.2% (group A) and 33.5 +/- 0.6% (group B) at four months, and 42.0 +/- 1.1% (group A) and 30.4 +/- 1.0% (group B) at 12 months. Baseline ABP and routine dialysis unit BP levels were not different between the groups. At 2, 4, 8, and 12 months of follow-up, there were no statistically significant differences in any BP parameters between groups or increases in any BP parameters in either group A or group B patients compared with baseline. At 12 months, the mean nighttime diastolic BP (DBP) in group A patients was slightly but significantly lower than the mean daytime DBP (daytime DBP 76.6 +/- 1.9 mm Hg vs. nighttime DBP 72.9 +/- 2.1 mm Hg, P < 0.05). The mean daytime and nighttime BPs were not different from each other at two, four, and eight months in group A or at any time in group B, and in both groups, most patients had little diurnal change in BP.

CONCLUSION

Correction of hct to normal with epoetin in chronic hemodialysis patients with cardiac disease did not cause increased BP as assessed by interdialytic ABP monitoring or by the measurement of routine predialysis and postdialysis BP. There was little diurnal change in systolic or diastolic BP at baseline or after correction of anemia to normal levels, and although mean nighttime DBP was lower than mean daytime DBP at 12 months in group A, the maintenance of normal hct levels did not affect the abnormal diurnal BP pattern seen at moderately anemic hct levels in most patients.

Ambulatory blood pressure monitoring is a useful clinical tool in nephrology

Hypertension is a key factor in the genesis and deterioration of many renal diseases and is also a risk factor for death in patients with end-stage renal disease. However, the standard methods of measurement are prone to variability, especially in patients undergoing dialysis. The technique of ambulatory blood pressure monitoring allows a better assessment of overall blood pressure levels and promises to assume a bigger role in the care of renal patients. Ambulatory blood pressure monitoring is widely used in hypertension trials, and the reports of several consensus meetings on the clinical uses of ambulatory blood pressure monitoring have been published. Two similar validation protocols now exist for ambulatory blood pressure monitors, and tables of population-based normal blood pressures for age and gender are available. The available evidence suggests that ambulatory blood pressure compared with blood pressure measured in the physician's office is better correlated to left ventricular mass in subjects with chronic renal disease. Furthermore, studies in subjects with chronic renal disease and those undergoing renal replacement therapy show that blood pressure control is suboptimal in many patients and that nocturnal blood pressure is generally higher than in control subjects. Further insights into overall blood pressure behavior in this population will certainly emerge in the future.

Influence of nycthemeral blood pressure pattern in treated hypertensive patients on hemodialysis

Arterial hypertension in end-stage renal disease (ESRD) patients is characterized by an altered nycthemeral blood pressure (BP) rhythm and an increased pulse pressure, and it could be suggested that this association of risk factors plays a major role in the cardiovascular prognosis of this population. The aim of this study was to determine the influence of nycthemeral BP pattern on arterial distensibility and pulsatile components of BP in treated hypertensive patients on regular hemodialysis. Forty-two hypertensive patients were included, and all underwent ambulatory BP and pulse wave velocity (PWV) measurements between the femoral and carotid arteries. The patients were divided into two groups according to the magnitude of the nocturnal fall in BP: dippers and non-dippers. The groups were similar in gender, age, duration of hemodialysis, body mass index, body size, history of cardiovascular complications, class and number of antihypertensive drugs used per patient. PWV was significantly higher in non-dippers. For the whole population, a stepwise regression analysis showed that PWV and erythropoietin therapy were independently related to the impaired nycthemeral BP pattern. In addition to its pressor effect, erythropoietin could have a deleterious influence on the ambulatory BP profile of treated hypertensive patients in ESRD. Arterial distensibility and nycthemeral BP impairment are linked, and these cardiovascular risk factors should be taken into account together for the management of hypertensive hemodialysis patients.

Ambulatory blood pressure monitoring in dialysis patients and estimation of mean interdialytic blood pressure

To define blood pressure (BP) patterns and control in dialysis patients, 48-hour ambulatory BP monitoring was performed in 36 hemodialysis and 18 peritoneal dialysis patients. Monitoring began during a dialysis session for hemodialysis patients. Data revealed significantly lower diastolic BP (DBP) and lower diastolic load (percentage of diastolic values > 90 mm Hg) in hemodialysis patients compared with peritoneal dialysis patients (80.6 mm Hg v 88.8 mm Hg, respectively, [P < 0.03] and 26% v 45%, respectively [P < 0.03]) for the 48-hour period. When the 2 days were analyzed separately, the difference in diastolic pressures and loads was significant only for the first (dialysis) day. Similarly, trends toward lower systolic BP (SBP) and systolic load in hemodialysis patients existed throughout monitoring and were greater in magnitude during the first day. BP data were fit to a random-coefficient growth curve model to detect periodicity. This sensitive model did not detect diurnal variation of BP in either group. The incidence of hypotension did not differ between the two groups (2.0% v 1.0% of total observations, hemodialysis v peritoneal dialysis). In the hemodialysis group, the proportion of hypotensive observations was significantly greater during the 4 hours postdialysis compared with other periods (5.6% v 1.6%; P < 0.02), a finding that likely reflects the practice of holding antihypertensives until after hemodialysis. However, patient diaries did not reflect hypotensive symptoms during this time. In the hemodialysis group, mean BP and predialysis BP did not correlate with interdialytic sodium load or weight gain. Predialysis and postdialysis BP (recorded by dialysis nurses) correlated significantly with mean BP. Predialysis SBP overestimated mean SBP by an average of 10 mm Hg, while postdialysis SBP underestimated mean SBP by an average of 7 mm Hg. To create formulas to estimate mean SBP and DBP in hemodialysis patients, multiple linear regression was used to model these variables against age, sex, race, and average prehemodialysis/posthemodialysis BP. The model achieved a high degree of fit (r2 = 0.72 for SBP; r2 = 0.65 for DBP), demonstrating that prehemodialysis and posthemodialysis BP can be used to predict mean BP in hemodialysis patients. In summary, our data show the absence of a diurnal variation of BP in dialysis patients and lower BP in hemodialysis patients compared with peritoneal dialysis patients. Among hemodialysis patients, more hypotension occurred after dialysis compared with other periods, and predialysis and postdialysis BP can be used to model mean BP levels.