Association of Intradialytic Hypertension with Left Ventricular Mass in Hypertensive Hemodialysis Patients Enrolled in the Blood Pressure in Dialysis (BID) Study

Epidemiology, Pathophysiology, and Clinical Perspectives of Intradialytic Hypertension

BACKGROUND

Individuals with end-stage renal disease on chronic hemodialysis (HD) may encounter numerous HD-associated complications, including intradialytic hypertension (IDHYPER). Although blood pressure (BP) follows a predictable course in the post-HD period, BP levels during the session may vary across the individuals. Typically, a decline in BP is noted during HD, but a significant proportion of patients exhibit a paradoxical elevation.

SUMMARY

Several studies have been conducted to understand the complexity of IDHYPER, but much remains to be elucidated in the future. This review article aimed to present the current evidence regarding the proposed definitions, the pathophysiologic background, the extent and clinical implications of IDHYPER, as well as the possible therapeutic options that have emerged from clinical studies.

KEY MESSAGES

IDHYPER is noted in approximately 15% of individuals undergoing HD. Several definitions have been proposed, with a systolic BP rise >10 mm Hg from pre- to post-dialysis in the hypertensive range in at least four out of six consecutive HD treatments being suggested by the latest Kidney Disease: Improving Global Outcomes. Concerning its pathophysiology, extracellular fluid overload is a crucial determinant, with endothelial dysfunction, sympathetic nervous system overdrive, renin-angiotensin-aldosterone system activation, and electrolyte alterations being important contributors. Although its association with ambulatory BP in the interdialytic period is controversial, IDHYPER is associated with adverse cardiovascular events and mortality. Moving to its management, the antihypertensive drugs of choice should ideally be nondialyzable with proven cardiovascular and mortality benefits. Finally, rigorous clinical and objective assessment of extracellular fluid volume is essential. Volume-overloaded patients should be instructed about the importance of sodium restriction, while physicians ought to alter HD settings toward a greater dry weight reduction. The use of a low-sodium dialysate and isothermic HD could also be considered on a case-by-case basis since no randomized evidence is currently available.

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.

Assessing accuracy of estimated dry weight in dialysis patients post transplantation: the kidney knows best

INTRODUCTION

Estimated dry weight is used to guide fluid removal during outpatient hemodialysis sessions. Errors in estimated dry weight can result in intradialytic hypotension and interdialytic fluid overload. The goal of this study was to assess the accuracy of estimated dry weight by comparing it to the 2-week post-transplant weight in two cohorts of hemodialysis patients.

METHODS

This observational, multi-center, retrospective cohort study included maintenance hemodialysis patients who underwent kidney transplantation at two medical centers in Massachusetts. The relationship between estimated dry weight pre-transplant and weight at week 2 post-transplant in patients with good allograft function (serum creatinine ≤ 1.5 mg/dL) was analyzed. Estimated dry weight was considered accurate if it was within ± 2% of the week 2 post-transplant weight.

RESULTS

Fifty seven patients with good allograft function were identified: mean age 54 ± 14 years, 32 (58%) from deceased donors, 22 (38.6%) females. 38 were Caucasian (66.7%), 11 Hispanic (19.3%), 3 black (5.3%), and 5 others (8.8%). 2-week mean post transplantation serum creatinine was 1.2 ± 0.2 mg/dL. Mean (SD) estimated dry weight was 71.4 ± 15.9. Before transplantation, only 14 (24.6%) patients were within ± 2% of the 2-week post-transplant weight; 23 (40.3%) were above and 20 (35.1%) were below.

CONCLUSIONS

Our point of view, based on the assumption that the weight of patients with good allograft function at 2 weeks post-transplant approaches their accurate dry weight, is that a majority of maintenance hemodialysis patients (75.4%) are hypervolemic or hypovolemic prior to renal transplantation. This highlights the importance of finding novel tools to achieve euvolemia in patients undertaking dialysis. Timely feedback regarding achieved weight 2 weeks post-transplant to treating nephrologists and dialysis centers may be a starting point for assessing accuracy of dry weight.

Dialysis unit blood pressure two hours after hemodialysis is useful for predicting home blood pressure and ambulatory blood pressure in maintenance hemodialysis patients

This study aimed to determine which BP measurement obtained in the HD unit correlated best with home BP and ambulatory BP monitoring (ABPM). We retrospectively analyzed data from 40 patients that received maintenance HD who had available home BP and ABPM data. Dialysis unit BPs were the averages of pre-, 2hr- (2 h after starting HD), and post-HD BP during a 9-month study. Home BP was defined as the average of morning and evening home BPs. Dialysis unit BP and home BP were compared over the 9-month study period. ABPM was performed once for 24 h in the absence of dialysis during the final 2 weeks of the study period and was compared to the 2-week dialysis unit BP and home BP. There was a significant difference between dialysis unit systolic blood pressure (SBP) and home SBP over the 9-month period. No significant difference was observed between the 2hr-HD SBP and home SBP. When analyzing 2 weeks of dialysis unit BP and home BP, including ABPM, SBPs were significantly different (dialysis unit BP > home BP > ABPM; P = 0.009). Consistent with the 9-month study period, no significant difference was observed between 2hr-HD SBP and home SBP (P = 0.809). The difference between 2hr-HD SBP and ambulatory SBP was not significant (P = 0.113). In conclusion, the 2hr-HD SBP might be useful for predicting home BP and ABPM in HD patients.

Effect of low dialysate sodium in the management of intradialytic hypertension in maintenance hemodialysis patients: A single-center Indian experience

BACKGROUND

High dialysate sodium is a significant contributor to intradialytic hypertension (IDH) in maintenance hemodialysis patients. In this study, we aimed to study the effect of low dialysate sodium on IDH in Indian hemodialysis patients.

MATERIALS AND METHODS

Fifty patients on maintenance hemodialysis for atleast 3 months with episodes of IDH were enrolled in this study. The study was performed in two different stages. In the first phase, patients were dialyzed with standard dialysate sodium (140 mEq/L) for eight consecutive sessions and in the second phase, they were dialyzed with low sodium dialysate (136 mEq/L) for eight consecutive sessions. Differences in pre, intradialytic, and post-HD blood pressure, interdialytic weight gain, mean serum sodium, intradialytic adverse events, and number of IDH episodes requiring intervention between the two phases were assessed.

RESULTS

The mean age of the study population was 52 years (36 males,14 females). The mean post-HD systolic and diastolic BP was 163.26 ± 9.58 mmHg and 88.60 ± 5.27 mmHg in the standard dialysate phase and 142.38 ± 14.09 mmHg and 84.58 ± 4.276 mmHg, respectively, in the low dialysate phase (p < 0.01). Interdialytic weight gain was 3.34 ± 0.9 and 3.11 ± 0.86 in the standard and low sodium dialysate phases, respectively (p = 0.19).The mean pre-HD plasma sodium level was 138.48 ± 3.69 and 135.80 ± 1.35 mEq/dl, respectively, in standard and low dialysate phases (p = 0.01). There was significant reduction in number of IDH episodes requiring intervention. There was no difference in hypotensive episodes, adverse events between the two phases.

CONCLUSION

In patients with intradialytic hypertension, low dialysate sodium significantly reduces the post-HD blood pressure and intradialytic hypertensive episodes, when compared with standard sodium dialysate.

Association of pre-pro-endothelin gene polymorphism and serum endothelin-1 with intradialytic hypertension in an Egyptian population

BACKGROUND

Intradialytic hypertension (IDH) is a major problem of hemodialysis and it is a multifactorial disorder and need early identification and management.

AIM

Evaluate the serum concentration of endothelin-1 in patients with IDH and healthy control and the impact of pre-pro-endothelin gene polymorphism on level of endothelin-1 and susceptibility to IDH in Egyptian population.

METHODS

The patient groups divided into group I, End stage renal disease (ESRD) on chronic hemodialysis with IDH (112); group II, ESRD on chronic hemodialysis without IDH (112); group III, healthy control (112). All undergone to full history, clinical examination, routine laboratory investigations, echocardiography, serum ET-1 level by ELISA and A(8002)G polymorphism detection in pre-pro-endothelin gene by PCR-RFLP.

RESULTS

Our results showed significantly higher concentration of Endothelin-1 (ET-1) in both patient groups than healthy control and in group with IDH than cases without IDH (p < 0.001). GG, GA and mutated G allele carry the risk of IDH (OR = 15.94, 13.5, 5.51 respectively p < 0.001). There was association between GG and GA genotypes and higher ET-1 level in both patient groups (p < 0.001) and association between GG and GA genotype and higher mean arterial pressure (MAP), delta MAP (DMAP) and increased left ventricular mass index (LVMI) in both patient groups (p = 0.001, 0.028).

CONCLUSION

Pre-pro-endothelin gene polymorphism A(8002)G is an independent risk factor for IDH through changing the level of ET-1 concentration in Egyptian population undergoing chronic hemodialysis.

Cardiac Imaging in Dialysis Patients

There is a well-established yet unexplained high prevalence of cardiovascular morbidity and mortality in individuals with end-stage kidney disease receiving dialysis. Potential causes include changes in cardiac structure and function, with increased left ventricular mass index as the best established cardiac structural change associated with this increase in mortality. However, in recent years, new echocardiographic and cardiac magnetic resonance imaging techniques have emerged that may provide novel markers that may better explain the mechanisms underlying the cardiovascular morbidity and mortality observed in end-stage kidney disease. This review outlines advances in cardiac imaging and the current status of imaging modalities, including echocardiography, cardiac magnetic resonance imaging, and cardiac positron emission tomography, to identify dialysis patients at high risk for cardiovascular mortality.

Movie watching during dialysis sessions reduces depression and anxiety and improves quality of life: A randomized clinical trial

OBJECTIVE

Evaluate the effect of watching comedy movies as a complementary practice during dialysis on levels of anxiety, depression, quality of life, stress, laboratory findings and intra-dialysis complications.

METHODS

A randomized clinical trial was conducted involving the practice of presenting comedy movies during dialysis. The primary outcome was depression. The secondary outcomes were anxiety, quality of life, stress, laboratory findings and intra-dialysis complications.ResultsTwenty-six patients were in the control group and 35 were in the experimental group. Significant intra-group differences [6.0 to 3.0 (p <0.001) and 8.0 to 4.0 (p <0.001), respectively] and inter-group differences [5.0 vs. 3.0 (p = 0.016) and 7.0 vs. 4.0 (p = 0.017), respectively] were found regarding anxiety and depression scores, with improvements in the experimental group. The experimental group was also less likely to have intra-dialysis complications, such as hypertension (p = 0.003) and headache (p = 0.020), and reported significant improvements in different domains of quality of life [symptoms/problems (p = 0.003); effects of the disease (p = 0.008); pain (p = 0.027); general health state (p = 0.004); and social function (p = 0.036)]. No significant differences were found in salivary cortisol or the results of the biochemical exams, with the exception of a reduction in hematocrit in the control group.ConclusionsThe proposed complementary practice was associated with reductions in anxiety and depression scores and intra-dialysis complications (hypertension and headache) as well as improvements in quality of life in patients with chronic kidney disease.

Dataset supporting blood pressure prediction for the management of chronic hemodialysis

Hemodialysis (HD) is a treatment given to patients with renal failure. Notable treatment-related complications include hypotension, cramps, insufficient blood flow, and arrhythmia. Most complications are associated with unstable blood pressure during HD. Physicians are devoted to seeking solutions to prevent or lower the incidence of possible complications. With advances in technology, big data have been obtained in various medical fields. The accumulated dialysis records in each HD session can be gathered to obtain big HD data with the potential to assist HD staff in increasing patient wellbeing. We generated a large stream of HD parameters collected from dialysis equipment associated with the Vital Info Portal gateway and correlated with the demographic data stored in the hospital information system from each HD session. We expect that the application of HD big data will greatly assist HD staff in treating intradialytic hypotension, setting optimal dialysate parameters, and even developing an intelligent early-warning system as well as providing individualized suggestions regarding dialysis settings in the future.