Association of Intradialytic Hypertension with Future Cardiovascular Events and Mortality in Hemodialysis Patients: Effects of Ambulatory Blood Pressure

Impact of barometric pressure on blood pressure during dialysis: Introducing intradialytic time-averaged cumulative systolic blood pressure (TACsBP-inD) as a new metric

BACKGROUND

Blood pressure is a crucial risk factor for hemodialysis patients, but the specific impact of weather factors, particularly barometric pressure, on blood pressure remains unclear. This study aims to examine the relationship between barometric pressure and blood pressure in hemodialysis patients.

METHODS

We conducted a single-center, retrospective study involving 122 hemodialysis patients in Japan, covering the period from August 2018 to October 2022. In addition to standard blood pressure indices, for the purpose of a more accurate assessment, we introduced the intradialytic time-averaged cumulative systolic blood pressure (TACsBP-inD). Multilevel mixed-effects linear regression models with random intercepts for each patient and spline analyses were used to evaluate the association between barometric pressure and blood pressure.

RESULTS

Our analysis demonstrated a positive correlation between barometric pressure and various intradialytic blood pressure indices, including TACsBP-inD, in both univariate and multivariate models. Spline analyses revealed a U-shaped relationship between barometric pressure and TACsBP-inD. Furthermore, categorized barometric pressure showed significantly positive coefficients for TACsBP-inD at both lower and higher pressure ranges, supporting the U-shaped trend. Subgroup analyses revealed that this positive association was not observed at lower pressures among males, obese individuals, and patients with diabetes, cardiovascular disease, and smoking habits, suggesting that blood pressure responses vary depending on patient profiles.

CONCLUSIONS

These findings emphasize the significant impact of barometric pressure on intradialytic blood pressure, suggesting that atmospheric conditions could be an important consideration in blood pressure management for hemodialysis patients.

Effects of spironolactone on intradialytic hypertension: a multicentre, double-blind, randomized, crossover study

Background

Intradialytic hypertension (IDH) is associated with an increase in hospitalization and mortality. Several studies have shown that spironolactone reduces pre-dialysis blood pressure. However, none evaluated its effect on IDH. This study aims to evaluate the effects of spironolactone on IDH.

Methods

A 24-week, two-treatment, four-period, multicentre, double-blind, randomized, crossover study was conducted in stable maintenance haemodialysis (HD) patients who experienced IDH in >30% of their sessions during the past 3 months. Each participant was randomly assigned to one of four treatment sequences. In each intervention period, patients received a single dose of 50 mg spironolactone or a placebo 30 minutes before undergoing HD for 4 weeks according to their preassigned sequence, separated by a 2-week washout period. The primary outcome was an incidence of IDH.

Results

A total of 49 eligible patients were recruited with a total of 1211 dialysis sessions. The mean age was 54 ± 14 years and the mean systolic and diastolic blood pressures (SBP and DBP) were 145 ± 15 and 75 ± 10 mmHg, respectively. All patients had hypertension. The average number of antihypertensive drugs was 3.5 ± 1.4. Spironolactone reduced the incidence of IDH compared with placebo (57% versus 69%, P for treatment effect < .001). Patients receiving spironolactone had lower peak intradialytic SBP (161 ± 14 versus 165 ± 13 mmHg, P = .003), mean intradialytic SBP (149 ± 13 versus 152 ± 12 mmHg, P = .01) and post-dialysis SBP (152 ± 15 versus 157 ± 14 mmHg, P < .001) than placebo.

Conclusion

In maintenance HD patients who had frequent IDH, a pre-dialysis 50-mg spironolactone administration significantly decreased the incidence of IDH.

Trial registration

Thai Clinical Trial Registry, reference number TCTR20200604013.

The association of sex differences in ambulatory blood pressure with cardiovascular events and mortality in dialysis patients

Male patients with pre-dialysis chronic kidney disease (CKD) have worse ambulatory blood pressure (BP) control than females; this is associated with higher mortality. Male hemodialysis patients have higher ambulatory BP levels than females. This analysis aimed to investigate the association of sex differences in ambulatory BP with cardiovascular events and mortality in hemodialysis individuals. 129 male and 91 female hemodialysis patients with valid 48-h BP monitoring were followed for 53.4 ± 31.1 months. The primary endpoint was cardiovascular mortality; the secondary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, resuscitation after cardiac arrest, heart failure-hospitalization, coronary or peripheral revascularization. Cumulative freedom from the primary endpoint was lower for women (logrank-p = 0.032), while cumulative-freedom from the secondary endpoint did not differ significantly between-groups (logrank-p = 0.644). The crude risk for cardiovascular mortality was significantly higher in women (HR = 1.613, 95% CI [1.037, 2.509]). The crude risk for the combined endpoint was not different between the two groups (HR = 0.918, 95% CI [0.638, 1.320]). After adjusting for major risk factors (age, diabetes, dialysis vintage, coronary disease and hemoglobin) no significant differences in the risk for both the primary and the secondary endpoint were observed between women and men (primary: HR = 1.295 (95% CI [0.808, 2.078]), secondary: HR = 0.763 (95% CI [0.521, 1.118])). After additional adjustment for 44-h systolic BP the above relationships did not alter (primary: HR = 1.329 (95% CI [0.826, 2.137]), secondary: HR = 0.808 (95% CI [0.551, 1.184])). In conclusion, female hemodialysis patients have higher crude but similar adjusted cardiovascular mortality rates compared to male counterparts. In contrast to pre-dialysis CKD, the neutral relationship between gender and adverse cardiovascular outcomes in hemodialysis is not further affected by ambulatory BP.

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.

Low dialysate sodium and 48-h ambulatory blood pressure in patients with intradialytic hypertension: a randomized crossover study

BACKGROUND

Intradialytic hypertension (IDH) is associated with increased risk for cardiovascular events and mortality. Patients with IDH exhibit higher 48-h blood pressure (BP) levels than patients without this condition. Volume and sodium excess are considered a major factor contributing in the development of this phenomenon. This study evaluated the effect of low (137 mEq/L) compared with standard (140 mEq/L) dialysate sodium concentration on 48-h BP in patients with IDH.

METHODS

In this randomized, single-blind, crossover study, 29 patients with IDH underwent four hemodialysis sessions with low (137 mEq/L) followed by four sessions with standard (140 mEq/L) dialysate sodium, or vice versa. Mean 48-h BP, pre-/post-dialysis and intradialytic BP, pre-dialysis weight, interdialytic weight gain (IDWG) and lung ultrasound B-lines were assessed.

RESULTS

Mean 48-h systolic/diastolic BP (SBP/DBP) were significantly lower with low compared with standard dialysate sodium concentration (137.6 ± 17.0/81.4 ± 13.7 mmHg with low vs 142.9 ± 14.5/84.0 ± 13.9 mmHg with standard dialysate sodium, P = .005/P = .007, respectively); SBP/DBP levels were also significantly lower during the 44-h and different 24-h periods. Low dialysate sodium significantly reduced post-dialysis (SBP/DBP: 150.3 ± 22.3/91.2 ± 15.1 mmHg with low vs 166.6 ± 17.3/94.5 ± 14.9 mmHg with standard dialysate sodium, P < .001/P = .134, respectively) and intradialytic (141.4 ± 18.0/85.0 ± 13.4 mmHg with low vs 147.5 ± 13.6/88.1 ± 12.5 mmHg with standard dialysate sodium, P = .034/P = .013, respectively) BP compared with standard dialysate sodium. Pre-dialysis weight, IDWG and pre-dialysis B lines were also significantly decreased with low dialysate sodium.

CONCLUSIONS

Low dialysate sodium concentration significantly reduced 48-h ambulatory BP compared with standard dialysate sodium in patients with IDH. These findings support low dialysate sodium as a major non-pharmacologic approach for BP management in patients with IDH.

TRIAL REGISTRATION

ClinicalTrials.gov study number NCT05430438.

Accuracy of 24 h ambulatory blood pressure recordings for diagnosing high 44 h blood pressure in hemodialysis: a diagnostic test study

Hypertension is highly prevalent in hemodialysis patients. Ambulatory-BP-monitoring(ABPM) during the 44 h interdialytic interval is recommended for hypertension diagnosis and management in these subjects. This study assessed the diagnostic accuracy of fixed 24 h ABPM recordings with 44 h BP in hemodialysis patients. 242 Greek hemodialysis patients that underwent valid 48 h ABPM(Mobil-O-Graph NG device) were included in the analysis. We used 44 h BP as reference method and tested the accuracy of the following BP metrics: 1st 24 h without HD period (20 h-1st), 1st 24 h including HD period (24 h-1st) and 2nd 24 h(24 h-2nd). All studied metrics showed strong correlations with 44 h SBP/DBP (20 h-1st: r = 0.973/0.978, 24 h-1st: r = 0.964/0.972 and 24 h-2nd: r = 0.978/0.977, respectively). In Bland-Altman analysis, small between-method differences (-1.70, -1.19 and +1.45 mmHg) with good 95% limits-of agreement([-10.83 to 7.43], [-11.12 to 8.74] and [-6.33 to 9.23] mmHg, respectively) for 20 h-1st, 24 h-1st and 24 h-2nd SBP were observed. The sensitivity/specificity and κ-statistic for diagnosing 44 h SBP ≥ 130 mmHg were high for 20 h-1st SBP(87.2%/96.0%, κ-statistic = 0.817), 24 h-1st SBP(88.7%/96.0%, κ-statistic = 0.833) and 24 h-2nd SBP (95.0%/88.1%, κ-statistic = 0.837). Similar observations were made for DBP. In ROC-analyses, all studied BP metrics showed excellent performance with high Area-Under-the- Curve values (20 h-1st: 0.983/0.992; 24 h-1st: 0.984/0.987 and 24 h-2nd: 0.982/0.989 for SBP/DBP respectively). Fixed 24 h ABPM recordings during either the first or the second day of interdialytic interval have high accuracy and strong agreement with 44 h BP in hemodialysis patients. Thus, ABPM recordings of either the first or the second interdialytic day could be used for hypertension diagnosis and management in these subjects.