The effects of nebivolol and irbesartan on postdialysis and ambulatory blood pressure in patients with intradialytic hypertension: a randomized cross-over study

Intradialytic Hypertension in Maintenance Hemodialysis

PURPOSE OF REVIEW

To summarize the current evidence regarding epidemiology, clinical pathophysiology, and latest therapeutic approaches for the management of intradialytic hypertension (IDH).

RECENT FINDINGS

IDH is a rather common complication of dialysis, affecting 10-15% of the patient population and significantly increasing the cardiovascular risk. Its pathophysiology involves multiple mechanisms, including volume and sodium overload, sympathetic nervous system (SNS) and renin-angiotensin-aldosterone system (RAAS) overactivity, endothelial dysfunction, and arterial stiffness. IDH management requires a combination of nonpharmacological and pharmacological interventions. The first mainly focus on volume control through dry weight optimization and modification of dialysate sodium, as studies show that strict volume control or low dialysate sodium can significantly reduce intradialytic and ambulatory blood pressure (BP). Pharmacological interventions have also been examined in research studies. Beta-blockers, particularly those with vasodilatory properties, can effectively target mechanisms such as SNS overactivity and endothelial dysfunction, and have shown some promising results reducing both intradialytic and ambulatory BP. Other drugs classes have also been explored as potential therapeutic options for IDH management, though further research is needed to clarify the efficacy of these interventions. A tailored approach addressing both the underlying pathophysiological mechanisms and individualized patient is warranted for improving BP control and cardiovascular outcomes in this high-risk population.

A, Lin SJ. Impact of Angiotensin Receptor Blockers (ARB) versus Other Antihypertensive Medication on Blood Pressure in Patients on Dialysis: A Meta-Analysis

Introduction

Hypertension is an important factor driving mortality among dialysis patients. Angiotensin-II receptor blocker (ARB) has been effective similarly to angiotensin-converting enzymes (ACEs) but with a low incidence of side effects.

Methodology

The meta-analysis included all published studies that investigated the effect of ARB on the hypertension in adult dialysis patients (≥18 years). Data extraction was guided by a predetermined checklist. Data sources of the retrieved studies were PubMed, MEDLINE, ScienceDirect, SCOPUS, Cochrane, Web of knowledge, and Google Scholar were systematically searched until February 2023. Using the RevMan 5 software, the mean difference for systolic and diastolic BP (SBP and DBP) and the risk ratio (RR) of the adverse events (AEs) were pooled from the selected studies. The random-effects model was used to compare the difference in the pre-and post-dialysis of the SBP and DBP. Data analyses were performed from December 2022 to February 2023. The primary outcome was the reduction in SBP and DBP in dialysis hypertensive patients who were on anti-hypertensive agents, and the secondary outcome was assessment of AE associated with the drug after dialysis (PROSPERO Registration: CRD42022355369).

Results

The initial search yielded 1,679 records, of which 84 studies underwent full-text evaluation, which identified 13 studies and 1,462 patients. The pooled standard MD for losartan with other anti-hypertensive agents, where the pre-dialysis SBP was 0.17 (95% confidence interval [CI]: -0.21-0.55) and the post-dialysis was 0.35 (95% CI: -0.17-1.02); yet, both are statistically non-significant, implies that there was no difference between Losartan and ARB drugs regarding the effect on the SBP. Diastolic BP for predialysis was -0.01 (95% CI: -0.65-0.63) and post-dialysis was 0.03 (95% CI: -0.24-0.30) and statistically non-significant. AEs by the ARB agents were lower compared to other anti-antihypertensive agents (relative risk [RR]: 1.01; 95% CI: 0.59-1.75) and statistically non-significant.

Conclusion

This systematic review and meta-analysis of RCT demonstrated that ARB and other anti-hypertensive medications had similar impacts on the treatment of hypertension.

Beta-blocker efficacy for intra- and interdialytic hypertension patients: a systematic review and meta-analysis

PURPOSE

Intradialytic hypertension affects 5-15% of hemodialysis patients, yet relevant studies are relatively scarce. It is also associated with higher interdialytic blood pressure. Beta-blockers can be preferred as antihypertensive drugs due to their superior blood pressure control, decreased risk of cardiovascular events, improved endothelial cell function, and decreased noradrenaline levels. Through this study, beta-blocker antihypertensive effects in intra- and interdialytic hypertension were analyzed.

METHODS

Systematic review and meta-analysis were performed following PRISMA guidelines. We registered our PROSPERO protocol (Registration ID: CRD42023446184) and included relevant full-text clinical trials or RCTs from 2008 to 2023 with predetermined keywords and criteria from multiple databases including PUBMED, COCHRANE, SCOPUS, and citation searching. Seven eligible articles were included in this review study.

RESULTS

Four studies with 82 participants for intradialytic hypertension evaluation were included. Meta-analysis showed a decrease in SBP in intradialytic hypertensive patients after beta-blocker intervention, with a significant estimated mean difference of - 15.19 mmHg (P < 0.00001; 95% CI - 19.47 to - 10.91). Supporting previous data, SBP remains constant between pre- and post-dialysis with beta-blocker therapy, with an insignificant estimated mean difference of - 2.72 mmHg (P = 0.29; 95% CI - 7.80 to 2.36). Whereas five studies with 142 participants were included for interdialytic hypertension evaluation. Meta-analysis shows a significant decrease in SBP before to after therapy, with an estimated mean difference of - 10.92 (P < 0.0001; 95% CI - 16.33 to - 5.51).

CONCLUSION

Beta-blocker treatment resulted in significant reductions in post-hemodialysis systolic blood pressure among intra- and interdialytic hypertensive patients.

Real-time dual prediction of intradialytic hypotension and hypertension using an explainable deep learning model

Both intradialytic hypotension (IDH) and hypertension (IDHTN) are associated with poor outcomes in hemodialysis patients, but a model predicting dual outcomes in real-time has never been developed. Herein, we developed an explainable deep learning model with a sequence-to-sequence-based attention network to predict both of these events simultaneously. We retrieved 302,774 hemodialysis sessions from the electronic health records of 11,110 patients, and these sessions were split into training (70%), validation (10%), and test (20%) datasets through patient randomization. The outcomes were defined when nadir systolic blood pressure (BP) < 90 mmHg (termed IDH-1), a decrease in systolic BP ≥ 20 mmHg and/or a decrease in mean arterial pressure ≥ 10 mmHg (termed IDH-2), or an increase in systolic BP ≥ 10 mmHg (i.e., IDHTN) occurred within 1 h. We developed a temporal fusion transformer (TFT)-based model and compared its performance in the test dataset, including receiver operating characteristic curve (AUROC) and area under the precision-recall curves (AUPRC), with those of other machine learning models, such as recurrent neural network, light gradient boosting machine, random forest, and logistic regression. Among all models, the TFT-based model achieved the highest AUROCs of 0.953 (0.952-0.954), 0.892 (0.891-0.893), and 0.889 (0.888-0.890) in predicting IDH-1, IDH-2, and IDHTN, respectively. The AUPRCs in the TFT-based model for these outcomes were higher than the other models. The factors that contributed the most to the prediction were age and previous session, which were time-invariant variables, as well as systolic BP and elapsed time, which were time-varying variables. The present TFT-based model predicts both IDH and IDHTN in real time and offers explainable variable importance.

Ambulatory central BP and arterial stiffness in patients with and without intradialytic hypertension

BACKGROUND

Increased arterial stiffness is suggested to be involved in the pathogenesis of intradialytic-hypertension (IDH). Ambulatory pulse-wave-velocity (PWV) is an independent predictor for all-cause-mortality in haemodialysis and its prognostic power is better than office PWV. This is the first study examining ambulatory central blood pressure (BP) and arterial stiffness parameters in patients with and without IDH.

METHODS

This study examined 45 patients with IDH (SBP rise ≥10 mmHg from pre- to post-dialysis and post-dialysis SBP ≥150 mmHg) in comparison with 197 patients without IDH. All participants underwent 48-h ABPM with Mobil-O-Graph-NG; parameters of central haemodynamics, wave reflection and PWV were estimated.

RESULTS

Age, dialysis vintage and interdialytic weight gain did not differ between-groups. IDH patients had higher 48-h cSBP (131.7 ± 16.2 vs. 119.2 ± 15.2 mmHg, p < 0.001), 48-h cDBP (86.7 ± 12.7 vs. 79.6 ± 11.5 mmHg, p < 0.001) and 48-h cPP (45.5 ± 10.4 vs. 39.8 ± 10.0 mmHg, p = 0.001) compared to patients without IDH. Similarly, during day- and nighttime periods, cSBP/cDBP and cPP levels were higher in IDH-patients compared to non-IDH. Forty-eight-hour augmentation pressure and index, but not AIx(75) were higher in IDH patients; 48-h PWV (10.0 ± 2.0 vs. 9.2 ± 2.1 m/s, p = 0.017) was significantly higher in patients with IDH. The two study groups displayed different trajectories in central BP and PWV over the course of the recording; IDH patients had steadily high values of the above variables during the 2 days of the interdialytic-interval, whereas non-IDH patients showed a gradual elevation, with significant increases from the 1st to 2nd 24 h.

CONCLUSIONS

IDH patients have significantly higher levels of ambulatory central BP and arterial stiffness parameters and a different course over the 48-h period compared with non-IDH patients. Increased arterial stiffness could be a prominent factor associated with the high burden of cardiovascular disease in this population.

Management of intradialytic hypertension: current evidence and future perspectives

Intradialytic hypertension (IDH), that is, a paradoxical rise in blood pressure (BP) during or immediately after a hemodialysis session, affects approximately 10-15% of the hemodialysis population. It is currently recognized as a phenomenon of major clinical significance as recent studies have shown that BP elevation extends to the whole interdialytic interval and associates with increased cardiovascular and all-cause mortality. The pathophysiology of IDH is complex involving volume and sodium overload, endothelial dysfunction, excess renin-angiotensin-aldosterone system and sympathetic nervous system activation, and other mechanisms. For several years, there was a scarcity of studies regarding IDH treatment; recently, however, several attempts to examine the effect of nonpharmacological and pharmacological measures on BP levels in IDH are made. This review attempts to summarize this latest evidence in the field of management of IDH and discuss areas for future research.

Intradialytic hypertension: epidemiology and pathophysiology of a silent killer

The term intradialytic hypertension (IDH) describes a paradoxical rise in blood pressure (BP) during or immediately after the hemodialysis session. Although it was formerly considered a phenomenon without clinical implications, current evidence suggests that IDH may affect up to 15% of hemodialysis patients and exhibit independent associations with future cardiovascular events and all-cause mortality. Furthermore, during the last decade, several studies have tried to elucidate the complex pathophysiological mechanisms responsible for this phenomenon. Volume overload, intradialytic sodium gain, overactivity of the sympathetic-nervous-system and renin-angiotensin-aldosterone system, endothelial dysfunction and dialysis-related electrolyte disturbances have been proposed to be involved in the pathogenesis of the BP increase during hemodialysis. This review attempts to summarize existing evidence on the epidemiology, pathophysiology and clinical characteristics of the distinct phenomenon of IDH.

Nebivolol combined with tetrahydrobiopterin affects diastolic function in spontaneously hypertensive rats via the nitric oxide/cyclic guanosine monophosphate signalling pathway

BACKGROUND

Hypertension is the the primary cause of diastolic heart failure. Oxidative stress plays an important role in cardiac diastolic dysfunction caused by hypertension. The occurrence of oxidative stress is related to the level of nitric oxide (NO) in the body. Tetrahydrobiopterin (BH4) is an essential cofactor for NO synthesis. Nebivolol can reduce myocardial oxidative stress and increase NO activity. Therefore, we investigated the effects of monotherapy or combination therapy of different doses of BH4 and nebivolol on cardiac diastolic function in spontaneously hypertensive rats, and preliminarily expounded the related mechanisms.

METHODS

Left ventricular function was evaluated by non-invasive echocardiographic assessment and invasive right carotid artery catheterization methods. ELISA was used to measure myocardial 3-nitrotyrosine content, NO production, and cyclic guanosine monophosphate (cGMP) concentration in the myocardium; quantitative real-time PCR (qRT-PCR) was used to determine endothelial nitric oxide synthase (eNOS), phospholamban and sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) mRNA expression levels; Western blot was used to detect the protein expression levels of eNOS and eNOS dimers in myocardial tissue, and immunohistochemical detection of cGMP expression in the myocardium was performed.

RESULTS

Studies have shown that compared with those in the control group, NO generation and the expression level of myocardial eNOS mRNA, eNOS expression of dimers, phospholamban, SERCA2a and cGMP increased significantly after the combined intervention of BH4 and nebivolol, while the expression of 3-nitrotyrosine was significantly decreased.

CONCLUSIONS

The combined treatment group had a synergistic effect on reducing myocardial oxidative stress, increasing eNOS content, and increasing NO production, and had a more obvious protective effect on diastolic dysfunction through the nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway.

The Effects of Nebivolol and Irbesartan on Ambulatory Aortic Blood Pressure and Arterial Stiffness in Hemodialysis Patients with Intradialytic Hypertension

BACKGROUND

Intradialytic hypertension occurs in 5-15% of hemodialysis patients and is associated with increased cardiovascular risk, but the responsible mechanisms remain unknown. This study examined the effects of nebivolol and irbesartan on ambulatory central blood pressure (BP), arterial stiffness, and wave-reflection parameters in patients with intradialytic hypertension.

METHODS

This is a prespecified analysis of a single-blind, randomized, cross-over study in 38 hemodialysis patients with intradialytic hypertension. Patients were randomized to nebivolol 5 mg followed byirbesartan 150 mg, or vice versa. In a non-randomized manner, the first half of the patients (n = 19) received a single drug dose 1 h prior to dialysis session and the remaining received the drugs for a whole week before the evaluation. Ambulatory central BP, arterial stiffness, and wave-reflection parameters were estimated with Mobil-O-Graph NG device, during a midweek dialysis day.

RESULTS

Intake of a single dose of nebivolol or irbesartan resulted in lower postdialysis central systolic BP (c-SBP) (baseline: 140.9 ± 15.4; nebivolol: 130.3 ± 19.5, p = 0.009; irbesartan: 127.3 ± 24.4 mm Hg, p = 0.007). Single-dose nebivolol also produced marginally lower 24-h c-SBP (p = 0.064) and lower 24-h central diastolic BP (c-DBP) (p = 0.029). Weekly administration of both drugs reduced postdialysis c-SBP (baseline: 144.1 ± 15.3; nebivolol: 131.8 ± 14.1, p = 0.014; irbesartan: 126.4 ± 17.8, p = 0.001) and 24-h c-SBP and c-DBP (baseline: 135.5 ± 10.3/91.9 ± 9.2; nebivolol: 126.4 ± 8.4/86.6 ± 7.2, p < 0.001/p = 0.002; irbesartan: 128.7 ± 11.6/87.0 ± 9.4, p = 0.061/p = 0.051 mm Hg). Single-dose intake of both drugs did not affect heart rate-adjusted augmentation index [AIx(75)], but decreased postdialysis pulse wave velocity (PWV). Importantly, weekly administration of both drugs reduced 24-h PWV (baseline: 10.0 ± 2.5; nebivolol: 9.7 ± 2.5, p = 0.012; irbesartan: 9.7 ± 2.7, p = 0.041). In between drug-group comparisons, no significant differences were noted.

CONCLUSIONS

This is the first randomized evaluation on the effects of pharmacological interventions on central BP and PWV in patients with intradialytic hypertension. Weekly administration of both nebivolol and irbesartan reduced 24-h central BP and PWV, but not AIx(75).

Bilateral renal artery stenosis as a cause of refractory intradialytic hypertension in a patient with end stage renal disease

Background

We report a 61-year-old female with end-stage renal disease (ESRD) secondary to polycystic kidney disease (PKD) complicated by intradialytic hypertension (IDH). Increased sympathetic drive leading to increased stroke volume and/or vasoconstriction with an inappropriate increase in peripheral vascular resistance (PVR) has been postulated to be the cause of IDH.

Case presentation

Attempts to control her blood pressure by reducing her goal weight; increasing dialysis times/ frequency and decreasing her sodium concentrate in the dialysis fluid were unsuccessful. Acting upon literature evidence suggesting renovascular disease as a cause of IDH, we referred her to an interventional radiologist for evaluation of the renal arteries. Selective angiogram of both renal arteries revealed right sided atherosclerotic renal artery stenosis (RAS) treated with insertion of a balloon mounted 6 mm stent and left sided fibromuscular dysplasia (FMD) treated with 5 mm balloon angioplasty.

Conclusions

This case highlights the need for interrogating the renal arteries radiologically for a potential cause in difficult to control IDH and comments on the association between PKD and FMD that has not yet been reported.