Evaluation of a novel brachial cuff-based oscillometric method for estimating central systolic pressure in hemodialysis patients

A Mother-Child Dyadic Approach to Evaluating Subclinical Cardiovascular Disease in Young Children: A Feasibility Study

BACKGROUND

Cardiovascular (CV) risk factors can be transmitted from mothers to their children. However, it is challenging to measure and identify subclinical CV risk in young children using traditional CV risk methods and metrics.

OBJECTIVE

The purpose of this study was to determine the feasibility of recruiting mother-child dyads and measuring arterial stiffness (pulse wave velocity, augmentation index/pressure), blood pressure (BP), BP circadian pattern, specifically nocturnal BP dipping, and CV health metrics in mothers and in children aged 1 to 5 years.

METHODS

All BP and arterial stiffness measures were obtained using the noninvasive automated oscillometric Mobil-O-Graph device. Also measured were blood cholesterol level; glucose level; body mass index (BMI); and smoking, diet, and physical activity history. Descriptive statistics were used for assessing recruitment feasibility and Pearson correlations for mother-child associations.

RESULTS

Thirty-five mother-child dyads completed the protocol. Recruitment reach was 89% and retention rate was 80%. Mothers were 34.3 ± 5.4 years old with a mean systolic BP (SBP) of 114.6 ± 9.5 mm Hg and BMI of 26.0 ± 6.5. Children were 3 ± 1.4 years old with a mean SBP of 103.3 ± 9.4 mm Hg and BMI z -scores of -0.3 ± 1.5. Arterial stiffness parameters were within normal ranges for mothers and children. Twenty-three percent of mothers did not exhibit nocturnal dipping (<10% decrease between day and nighttime SBP). Maternal SBP was positively correlated with child BMI z -scores ( r = 0.42, P = .022) as well as mother-child augmentation pressure ( r = 0.51, P = .010).

CONCLUSIONS

Our findings support using a mother-child approach and novel noninvasive approaches to assess and target CV risk in mothers and their young children.

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.

Blunted Microvascular Reactivity in Psoriasis Patients in the Absence of Cardiovascular Disease, as Assessed by Laser Speckle Contrast Imaging

Psoriasis is associated with accelerated rates of cardiovascular disease (CVD). Laser Speckle Contrast Imaging (LSCI) is a novel, non-interventional technique for the dynamic assessment of microvascular endothelial dysfunction, which represents an early precursor of CVD. We investigated whether skin microvascular reactivity is impaired in psoriasis and whether an association exists with large artery stiffening. Skin microvascular reactivity was assessed with LSCI combined with post-occlusive reactive hyperaemia protocol in psoriasis patients and controls in the absence of established CVD. Arterial stiffness and central hemodynamics were assessed throughout a whole 24 h period with the Mobil-O-Graph device. Most LSCI indices of microvascular reactivity were impaired in psoriasis patients (n = 90) compared to controls (n = 45) [baseline flux; occlusion flux; peak-to-baseline magnitude; baseline cutaneous vascular conductance (CVC); percentage increase in CVC, p < 0.001 for all comparisons]. In multivariate analysis, psoriatic disease predicted the above markers independently of classical CVD risk factors. Augmentation index, peripheral pulse pressure, and central systolic/diastolic blood pressure correlated with LSCI microvascular responses in the study population (n = 135). Pulse wave velocity significantly correlated with nearly all LSCI parameters, while the association with baseline flux was independent of CVD risk factors and psoriatic disease in multivariate analysis (beta = 0.096, p = 0.039). This study provides evidence of altered skin microvascular responses in psoriasis by use of LSCI, and interaction with macrovascular dysfunction, before the establishment of overt CVD. A non-interventional approach of skin microcirculation with LSCI might be used as an early indicator of vascular health in psoriasis.

Viewpoint: The Case for Non-Invasive Central Aortic Pressure Monitoring in the Management of Hypertension

Elevated central aortic pressure indices (e.g., systolic pressure and pulse pressure) predict cardiovascular (CV) events and mortality in addition to structural changes (e.g., left ventricular hypertrophy, carotid intima-media thickness and reduced glomerular filtration rate). These elevated risks have been shown in multiple studies to be superior to, and in others, at least as high as that associated with brachial pressures. Threshold values for the diagnosis of elevated central arterial pressures have been defined and can be considered target goals of treatment. Measurements of central arterial pressures can be incorporated into the current approaches to hypertension management utilizing currently available non-invasive devices that measure central pressures during the measurement of brachial BP. The objective of this review is to outline the rationale and evidence supporting incorporation of central aortic pressure monitoring into the care of patients with hypertension.

The Oscillometric Pulse Wave Analysis Is Useful in Evaluating the Arterial Stiffness of Obese Children with Relevant Cardiometabolic Risks

Early detection of all complications of childhood obesity is imperative in order to minimize effects. Obesity causes vascular disruptions, including early increased arterial stiffness and high blood pressure. This study’s aim is to assess the reliability of pulse wave analysis (PWA) in obese children and how additional risk factors influence the evaluated parameters. We analyzed 55 children aged 6–18 years old by measuring their pulse wave velocity (PWV), augmentation index (AIx), peripheral blood pressure (SBP, DBP), heart rate, central blood pressure (cSBP, cDBP) and central pulse pressure (cPP). We used the oscillometric IEM Mobil-O-Graph and performed a single-point brachial measurement. The subjects were divided into two groups: obese (n = 30) and normal-weight (n = 25) and were clinically and anamnestically assessed. BMI and waist circumference are significantly correlated to higher values for PWV, SBP, DBP, cSBP, and cDBP. Weight significantly predicts PWV, SBP, DBP and cPP. The risk factors that significantly influence the PWA and BP values are: a cardiometabolically risky pregnancy (higher PWV, AIx, SBP), active and passive smoking (higher PWV, SBP, cSBP, cDBP), sleep deprivation (higher PWV, SBP, cSBP) and sedentariness (higher PWV, AIx, peripheral and central BP). We conclude that obese children with specific additional cardiometabolic risk factors present increased arterial stiffness and higher blood pressure values.

Effect of Empagliflozin and Dapagliflozin on Ambulatory Arterial Stiffness in Patients with Type 2 Diabetes Mellitus and Cardiovascular Co-Morbidities: A Prospective, Observational Study

Background and Objectives: Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of cardiovascular disease. Arterial stiffness is an independent prognostic marker for cardiovascular disease development. We aimed at determining the effect of two different sodium-glucose co-transporter-2 (SGLT-2) inhibitors on ambulatory arterial stiffness in individuals with T2DM. Materials and Methods: In this single-center, single-arm, prospective study performed from January 2020 to August 2021, we planned to enroll adult subjects with T2DM and stable antidiabetic and antihypertensive treatment, assigned either to empagliflozin or dapagliflozin for 6 months. All eligible subjects underwent ambulatory blood pressure monitoring. We set as the primary efficacy outcome the change in ambulatory pulse wave velocity (PWV) from baseline to week 24. Results: We finally enrolled 46 diabetic subjects, with a mean age of 62.89 (8.53) years and mean T2DM duration of 9.72 (6.37) years. Thirty patients received dapagliflozin, while sixteen patients received empagliflozin. Due to COVID-19 pandemic restrictive measures during the study, the mean follow-up period extended from 6 months to 9.98 (3.27) months. Regarding the prespecified primary efficacy outcome, we found that the SGLT-2 inhibitor treatment did not have a significant effect on PWV (p = 0.65). Prior history of cardiovascular disease did not significantly affect the observed effects. Other indices of arterial stiffness, such as augmentation index and central pulse pressure, were not significantly affected, neither by empagliflozin nor by dapagliflozin. Conclusions: SGLT-2 inhibitor treatment with empagliflozin or dapagliflozin in subjects with T2DM failed to improve ambulatory PWV over a mean follow-up of 10 months. Registration number: ISRCTN88851713.

Pulse Wave Velocity for Risk Stratification of Patients with Aortic Aneurysm

Background: Patients with an aortic aneurysm are at high cardiovascular risk. Pulse wave velocity (PWV) is used as a parameter for risk stratification but may be affected by aortic disease (AoD). This study aimed to investigate the dependence of PWV on treated or untreated AoD and to identify modifiable factors of PWV. Methods: The measurement of PWV with the Mobil-O-Graph was performed fully automatically in a collective of 381 patients (75.6% male and 24.4% female). Of all patients, 53.8% had nonaortic atherosclerotic vascular disease (AVD), 28.9% had treated AoD, and 17.3% had untreated AoD. Results: There was a statistically significant effect of age (R2 = 0.838) and current systolic blood pressure (SBP) on PWV (page corrected < 0.05). After correction for age, no statistically significant difference was found between the PWV of men and women, patients with different body weights or degrees of chronic kidney disease, diabetics and nondiabetics, and smokers and nonsmokers. Comparison between patients with nonaortic AVD and treated or untreated AoD revealed no statistically significant differences (PWVnonaortic AVD 10.0 ± 1.8 m/s, PWVtreated AoD 10.0 ± 1.5 m/s, PWVuntreated AoD 9.8 ± 1.6 m/s; page corrected > 0.05). Conclusions: PWV determined with the Mobil-O-Graph correlated with age and current SBP. Neither aortic disease versus nonaortic AVD, its treatment, nor other cardiovascular risk factors had a significant effect on PWV. Successful blood pressure control is crucial to avoid high PWV and thus an increase in cardiovascular events.

Effect of sodium-glucose co-transporter-2 inhibitors on arterial stiffness: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Arterial stiffness represents an established cardiovascular risk marker. Sodium-glucose co-transporter-2 (SGLT-2) inhibitors have significant cardio-protective effects. Herein we sought to determine the effect of SGLT-2 inhibitors on pulse wave velocity (PWV).

METHODS

We searched PubMed, Cochrane Library, and grey literature from inception to 7^th February 2022 for randomized controlled trials (RCTs) enrolling adult subjects with or without type 2 diabetes mellitus (T2DM), assigned to a SGLT-2 inhibitor versus control and addressing their effect on PWV. We set as primary efficacy outcome the change in PWV with SGLT-2 inhibitors versus placebo or control.

RESULTS

We pooled data from six trials in a total of 452 enrolled participants assigned either to SGLT-2 inhibitor or control. Overall, SGLT-2 inhibitor treatment compared to control resulted in a nonsignificant decrease in PWV. Exclusion of a trial utilizing cardiac magnetic resonance imaging for the assessment of PWV demonstrated that SGLT-2 inhibitors induce a significant reduction in PWV by 0.21 m/s. When we restricted our analysis to RCTs enrolling subjects with T2DM, we observed that SGLT-2 inhibitor compared to control resulted in a significant decrease in PWV by 0.17 m/s.

CONCLUSION

SGLT-2 inhibitors do not decrease PWV in patients with established cardiovascular disease or cardiovascular risk factors. However, we have shown that SGLT-2 inhibitors lead to a slight, but significant decrease in PWV in patients with T2DM. The latter finding is of great value, based on the significant correlation between PWV and micro- and macro-vascular complications of T2DM.

Feeding during Dialysis Increases Intradialytic Blood Pressure Variability and Reduces Dialysis Adequacy

Whether hemodialysis patients should be allowed or even encouraged to eat during dialysis remains a controversial topic. This cross-over study aimed to evaluate the impact of feeding during dialysis on intradialytic blood pressure (BP) profile and dialysis adequacy in 26 patients receiving thrice-weekly, in-center hemodialysis. Over three consecutive mid-week dialysis sessions, intradialytic BP was monitored using the Mobil-O-Graph device (IEM, Stolberg, Germany). Blood samples were also obtained for the determination of the urea reduction ratio (URR). At baseline, patients underwent dialysis without the provision of a meal. In phases A and B, a meal with either high-protein (1.5 gr/kg of body weight) or low-protein (0.7 gr/kg of body weight) content was administered 1 h after the initiation of dialysis. The sequence of meals (high-protein and low-protein or vice versa) was randomized. Average intradialytic systolic BP (SBP) was similar on all three occasions. However, compared with baseline, the standard deviation (SD) (11.7 ± 4.1 vs. 15.6 ± 7.6 mmHg, p < 0.01), coefficient of variation (CV) (9.5 ± 3.7% vs. 12.4 ± 6.0%, p < 0.01) and average real variability (ARV) (9.4 ± 3.9 vs. 12.1 ± 5.2 mmHg, p < 0.01) of intradialytic SBP were higher in phase A. Similarly, compared with the baseline evaluation, all three indices of intradialytic SBP variability were higher in phase B (SD: 11.7 ± 4.1 vs. 14.1 ± 4.5 mmHg, p < 0.05; CV: 9.5 ± 3.7% vs. 11.1 ± 3.8%, p < 0.05; ARV: 9.4 ± 3.9 vs. 10.9 ± 3.9 mmHg, p < 0.05). Compared with dialysis without a meal, the consumption of a high-protein or low-protein meal resulted in a lower URR (73.4 ± 4.3% vs. 65.7 ± 10.7%, p < 0.001 in phase A and 73.4 ± 4.3% vs. 67.6 ± 4.3%, p < 0.001 in phase B, respectively). In conclusion, in the present study, feeding during dialysis was associated with higher intradialytic SBP variability and reduced adequacy of the delivered dialysis.

Pulse wave velocity in South African women and children: comparison between the Mobil-O-Graph and SphygmoCor XCEL devices

BACKGROUND

Carotid-femoral pulse wave velocity (PWV) is the gold-standard noninvasive measure of arterial stiffness. Data comparing tonometry-based devices such as the SphygmoCor XCEL to simpler brachial-cuff-based estimates of PWV, such as from the Mobil-O-Graph in African populations are sparse. We therefore aimed to compare PWV measured by the Mobil-O-Graph and the SphygmoCor XCEL device in a sample of South African women and children.

METHODS

Women (n = 85) 29 years [interquartile range (IQR): 29-69] and their children/grandchildren (n = 27) 7 years (IQR: 4-11) were recruited for PWV measurement with Mobil-O-Graph and SphygmoCor XCEL on the same day. Wilcoxon signed-rank test, regression analysis, spearman correlation and Bland-Altman plots were used for PWV comparison between devices.

RESULTS

For adults, the SphygmoCor XCEL device had a significantly higher PWV (7.3 m/s, IQR: 6.4-8.5) compared with the Mobil-O-Graph (5.9 m/s, IQR: 5.0-8.1, P = 0.001) with a correlation coefficient of 0.809 (P ≤ 0.001). Bland--Altman analysis indicated an acceptable level of agreement but significant bias (mean difference PWV: 0.90 ± 1.02 m/s; limits of agreement: -1.10 to 2.90). The odds of having a PWV difference more than 1 m/s decreased with a higher age [odds ratio (OR): 0.95, 95% confidence interval (95% CI) = 0.92-0.98] and increased with greater height (OR: 1.10, 95% CI = 1.01-1.21, P = 0.03) in multivariable analysis. In children, the Bland-Altman indicated an excellent level of agreement (-0.03 ± 0.63 m/s; limits of agreement: -1.26 to 1.21), but no correlation was found (rs = 0.08, P = 0.71).

CONCLUSION

Particularly in younger and taller women, the Mobil-O-Graph significantly underestimated PWV compared with the SphygmoCor. Although no correlation was found between the two devices for children, further research is required due to the small sample size. Furthermore, the clinical value of both methods in young African populations requires further investigation.

A SAGE score cutoff that predicts high-pulse wave velocity as measured by oscillometric devices in Brazilian hypertensive patients

We aimed to identify the optimal cutoff SAGE score for Brazilian hypertensive patients who had their pulse wave velocity (PWV) measured with oscillometric devices. A retrospective analysis of patients who underwent central blood pressure measurement using a validated oscillometric device, the Mobil-O-Graph® (IEM, Stolberg, Germany), between 2012 and 2019 was performed. Patients with arterial hypertension and available data on all SAGE parameters were selected. An ROC curve was constructed using the Youden index to define the best score to identify patients at high risk for high PWV. A total of 837 patients met the criteria for SAGE and diagnosis of hypertension. The median age was 59.0 years (interquartile range [IQR]: 47.0-68.0), and 50.7% of the patients were women. The following comorbidities and conditions were present: dyslipidemia (37.4%), diabetes (20.7%), a body mass index score ≥30 kg/m² (36.6%), use of antihypertensive drugs (69.5%), and smoking (18.3%). The median peripheral blood pressure was 128 mmHg (IQR: 117-138 mmHg) for systolic and 81 mmHg (IQR: 73-90 mmHg) for diastolic blood pressure. The median PWV was 8.3 m/s (7.1-9.8 m/s), and the prevalence of high PWV (≥10 m/s) was 22.9% (192 patients). A cutoff SAGE score ≥8 was effective at identifying a high risk of PWV ≥ 10 m/s, achieving 67.19% sensitivity (95% CI: 60.1-73.8) and 93.95% specificity (95% CI: 91.8-95.7). With this cutoff point, 1 out of every 5 treated hypertensive patients would be referred for a PWV measurement. A SAGE score of ≥8 identified Brazilian hypertensive patients with a high risk of future cardiovascular events (PWV ≥ 10 m/s).

Ambulatory monitoring of central arterial pressure, wave reflections, and arterial stiffness in patients at cardiovascular risk

This paper reviews current 24 h ambulatory noninvasive technologies for pulse wave analysis (PWA) providing central arterial pressure, pulse wave velocity, and augmentation index and the scientific evidence supporting their use in the clinical management of patients with arterial hypertension or at risk for cardiovascular complications.The most outstanding value of these techniques lies in the fact that they are user-friendly, mostly operator independent, and enable the evaluation of vascular function during daily-life conditions, allowing to obtain repeated measurements in different out-of-office circumstances, less artificial than those of the laboratory or doctor's office.Studies performed so far suggest that 24 h PWA may represent a potentially promising tool for evaluating vascular function, structure, and damage in daily-life conditions and promoting early screening in subjects at risk. The current evidence in favor of such an approach in the clinical practice is still limited and does not recommend its routine use. In particular, at the moment, there is a shortage of long-term prognostic studies able to support the predictive value of 24 h PWA. Finally, the accuracy of the measures is strongly dependent on the type of technology and device employed with lack of interoperability among the devices that deeply affects comparability of results among studies using different technologies. It is thus mandatory in the near future to promote proper validation studies, for instance using the ARTERY protocol, and to plan well-designed long-term longitudinal studies that may prove the accuracy and high predictive value of PWA in ambulatory conditions.

Pulse Wave Velocity Assessment for Cardiovascular Risk Prognostication in ESKD: Weighting Recent Evidence

BACKGROUND

Among patients with end-stage kidney disease (ESKD), arterial stiffness is considered as a powerful predictor of cardiovascular (CV) morbidity and mortality. However, the relevance of aortic pulse wave velocity (PWV) as a prognostic biomarker for CV risk estimation is not yet fully clear.

METHODS

We performed a systematic search of Medline/PubMed database from inception through August 21, 2019 to identify observational cohort studies conducted in ESKD patients and exploring the association of PWV with CV events and mortality.

RESULTS

Whereas "historical" cohort studies showed aortic PWV to be associated with higher risk of CV and all-cause mortality, recent studies failed to reproduce the independent predictive value of aortic PWV in older ESKD patients. Studies using state-of-the-art prognostic tests showed that the addition of aortic PWV to standard clinical risk scores could only modestly improve CV risk reclassification. Studies associating improvement in PWV in response to blood pressure (BP)-lowering with improvement in survival cannot demonstrate direct cause-and-effect associations due to their observational design and absence of accurate methodology to assess the BP burden.

CONCLUSION

Despite the strong pathophysiological relevance of arterial stiffness as a mediator of CV disease in ESKD, the assessment of aortic PWV for CV risk stratification in this population appears to be of limited value. Whether aortic PWV assessment is valuable in guiding CV risk factor management and whether such a therapeutic approach is translated into improvement in clinical outcomes, is an issue of clinical relevance that warrants investigation in properly-designed randomized trials.

Dapagliflozin Does Not Affect Short-Term Blood Pressure Variability in Patients With Type 2 Diabetes Mellitus

BACKGROUND

Increased blood pressure variability (BPV) is associated with increased cardiovascular and all-cause mortality in patients with type-2 diabetes mellitus (T2DM). Sodium-glucose co-transporter 2 (SGLT-2) inhibitors decrease the incidence of cardiovascular events, renal events, and death in this population. This study aimed to evaluate the effect of dapagliflozin on short-term BPV in patients with T2DM.

METHODS

This is a secondary analysis of a double-blind, randomized, placebo-controlled trial in 85 patients with T2DM. Subjects were randomized to dapagliflozin 10 mg/day or placebo for 12 weeks. All participants underwent 24-hour ambulatory blood pressure (BP) monitoring with Mobil-O-Graph-NG device at baseline and study-end. SD, weighted SD (wSD), coefficient of variation, average real variability (ARV), and variation independent of mean were calculated for the 24-hour, daytime and nighttime periods.

RESULTS

Dapagliflozin reduced 24-hour brachial BP compared with placebo. From baseline to study-end 24-hour brachial BPV indexes did not change with dapagliflozin (SBP-ARV: 11.51 ± 3.45 vs. 11.05 ± 3.35; P = 0.326, SBP-wSD: 13.59 ± 3.60 vs. 13.48 ± 3.33; P = 0.811) or placebo (SBP-ARV: 11.47 ± 3.63 vs. 11.05 ± 3.00; P = 0.388, SBP-wSD: 13.85 ± 4.38 vs. 13.97 ± 3.87; P = 0.308). Similarly, no significant changes in BPV indexes for daytime and nighttime were observed in any group. At study-end, no between-group differences were observed for any BPV index. Deltas (Δ) of all indexes during follow-up were minimal and not different between groups (SBP-wSD: dapagliflozin: -0.11 ± 3.05 vs. placebo: 0.12 ± 4.20; P = 0.227).

CONCLUSIONS

This study is the first to evaluate the effects of an SGLT-2 inhibitor on short-term BPV in T2DM, showing no effect of dapagliflozin on all BPV indexes studied.

CLINICAL TRIALS REGISTRATION

Trial Number NCT02887677.

A comparative analysis of ambulatory BP profile and arterial stiffness between CAPD and APD

Prior studies have associated automated peritoneal dialysis (APD) with less effective volume and blood pressure (BP) control as compared with continuous ambulatory peritoneal dialysis (CAPD). Our study aimed to compare the volume status, ambulatory BP profile and severity of arterial stiffness between patients treated with CAPD versus APD. In a case-control design, 28 CAPD patients were matched in 1:1 ratio with 28 controls receiving APD for age, gender and diabetic status. Body composition was assessed with the method of bioimpendence spectroscopy. Twenty-four hours ambulatory BP monitoring with the Mobil-O-Graph device (IEM, Germany) was performed to determine peripheral and central hemodynamic parameters, heart rate-adjusted augmentation index (AIx75) and pulse wave velocity (PWV). Standardized office BP, antihypertensive medication use and extracellular-to-total body water ratio did not differ between CAPD and APD groups. Twenty-four hours brachial systolic BP (129.0 ± 17.3 vs. 128.1 ± 14.2 mmHg, P = 0.83) and 24-h aortic systolic BP (116.9 ± 16.4 vs. 116.4 ± 11.6 mmHg, P = 0.87) were similar in patients treated with CAPD versus APD. Similarly, there was no significant difference between PD modalities in severity of arterial stiffness, as assessed with 24-h AIx75 (24.8 ± 8.9 vs. 22.5 ± 9.1, P = 0.36) and 24-h PWV (9.1 ± 2.4 vs. 8.8 ± 2.1 m/s, P = 0.61). The present study suggests that there is no difference in peripheral and central hemodynamic parameters as well as in the severity of arterial stiffness between CAPD and APD. However, these observations should be interpreted within the context of clinical characteristics of patients included in this case-control study. The comparative effectiveness of these 2 PD modalities warrants further investigation in larger longitudinal studies.

Age dependence of brachial cuff-based ambulatory PWV in end-stage kidney disease patients undergoing long-term peritoneal dialysis

BACKGROUND

The newly introduced device Mobil-O-Graph (IEM, Stolberg, Germany) combines brachial cuff oscillometry and pulse wave analysis, enabling the determination of pulse wave velocity (PWV) via complex mathematic algorithms during 24-h ambulatory blood pressure monitoring (ABPM). However, the determinants of oscillometric PWV in the end-stage kidney disease (ESKD) population remain poorly understood.

METHODS

In this study, 81 ESKD patients undergoing long-term peritoneal dialysis underwent 24-h ABPM with the Mobil-O-Graph device. The association of 24-h oscillometric PWV with several demographic, clinical and haemodynamic parameters was explored using linear regression analysis.

RESULTS

In univariate analysis, among 21 risk factors, 24-h PWV exhibited a positive relationship with age, body mass index, overhydration assessed via bioimpedance spectroscopy, diabetic status, history of dyslipidaemia and coronary heart disease, and it had a negative relationship with female sex and 24-h heart rate. In stepwise multivariate analysis, age (β: 0.883), 24-h systolic blood pressure (BP) (β: 0.217) and 24-h heart rate (β: -0.083) were the only three factors that remained as independent determinants of 24-h PWV (adjusted R ² = 0.929). These associations were not modified when all 21 risk factors were analysed conjointly or when the model included only variables shown to be significant in univariate comparisons.

CONCLUSION

The present study shows that age together with simultaneously assessed oscillometric BP and heart rate are the major determinants of Mobil-O-Graph-derived PWV, explaining >90% of the total variation of this marker. This age dependence of oscillometric PWV limits the validity of this marker to detect the premature vascular ageing, a unique characteristic of vascular remodelling in ESKD.

Consequences of Supraphysiological Dialysate Magnesium on Arterial Stiffness, Hemodynamic Profile, and Endothelial Function in Hemodialysis: A Randomized Crossover Study Followed by a Non-Controlled Follow-Up Phase

Introduction

Increasing dialysate magnesium (D-Mg²⁺) appears to be an intriguing strategy to obtain cardiovascular benefits in subjects with end-stage kidney disease (ESKD) on hemodialysis. To date, however, hemodialysis guidelines do not suggest to increase D-Mg²⁺ routinely set at 0.50 mmol/L.

Methods

A randomized 4-week crossover study aimed at investigating the consequences of increasing D-Mg²⁺ from 0.50 to 0.75 mmol/L on arterial stiffness, hemodynamic profile, and endothelial function in subjects undergoing hemodialysis. The long-term effect of higher D-Mg²⁺ on mineral metabolism markers was investigated in a 6-month follow-up. Data were analyzed by linear mixed models for repeated measures.

Results

Data of 39 patients were analyzed. Pulse wave velocity and pulse pressure significantly decreased on the higher D-Mg²⁺ compared with the standard one by − 0.91 m/s (95% confidence interval − 1.52 to − 0.29; p = 0.01) and − 9.61 mmHg (− 18.89 to − 0.33, p = 0.04), respectively. A significant reduction in systolic blood pressure of − 12.96 mmHg (− 24.71 to − 1.22, p = 0.03) was also observed. No period or carryover effects were observed. During the long-term follow-up phase the higher D-Mg²⁺ significantly increased ionized and total serum Mg (respectively from 0.54 to 0.64 and from 0.84 to 1.07 mmol/L; mean percentage change from baseline to follow-up + 21% and + 27%; p ≤ 0.001), while parathormone (PTH) decreased significantly (from 36.6 to 34.4 pmol/L; % change − 11%, p = 0.03).

Conclusions

Increasing dialysate magnesium improves vascular stiffness in subjects undergoing maintenance hemodialysis. The present findings merit a larger trial to evaluate the effects of 0.75 mmol/L D-Mg²⁺ on major clinical outcomes.

Trial Registration

The study was retrospectively registered on the ISRCTN registry (ISRCTN 74139255) on 18 June 2020.

Comparison of ambulatory central hemodynamics and arterial stiffness in patients with diabetic and non-diabetic CKD

Increased arterial stiffness is independently associated with renal function decline in patients with diabetes mellitus (DM). Whether DM has additional deleterious effects on central hemodynamics and arterial stiffness in chronic kidney disease (CKD) patients is yet unknown. This study aimed to compare ambulatory central BP, arterial stiffness parameters, and trajectories between patients with diabetic and non‐diabetic CKD. This study examined 48 diabetic and 48 non‐diabetic adult patients (>18 years) with CKD (eGFR: <90 and ≥15 ml/min/1.73 m²), matched in a 1:1 ratio for age, sex, and eGFR within CKD stages (2, 3a, 3b and 4). All patients underwent 24‐h ABPM with the Mobil‐O‐Graph device. Parameters of central hemodynamics [central systolic (cSBP) and diastolic blood pressure (cDBP), pulse pressure (PP)], wave reflection [augmentation index (AIx), and pressure (AP)] and pulse wave velocity (PWV) were estimated from the 24‐h recordings. Diabetic CKD patients had higher 24‐h cSBP (118.57 ± 10.05 vs. 111.59 ± 9.46, P = .001) and 24‐h cPP (41.48 ± 6.80 vs. 35.25 ± 6.98, P < .001) but similar 24‐h cDBP (77.09 ± 8.14 vs. 76.34 ± 6.75 mmHg, P = .625) levels compared to patients with non‐diabetic CKD. During day‐ and nighttime periods, cSBP and cPP levels were higher in diabetics compared to non‐diabetics. 24‐h PWV (10.10 ± 1.62 vs. 9.61 ± 1.80 m/s, P = .165) was numerically higher in patients with DM, but no between‐group differences were noted in augmentation pressure and index. In multivariate analysis, DM, female gender, and peripheral SBP were independently associated with higher cPP levels. Patients with diabetic CKD have higher ambulatory cSBP and increased arterial stiffness, as indicated by higher ambulatory cPP. These finding suggest that DM is a factor independently contributing to the adverse macrocirculatory profile of CKD patients.

The presence of diabetes mellitus further impairs structural and functional capillary density in patients with chronic kidney disease

OBJECTIVE

Endothelial dysfunction has been associated with increased cardiovascular events and overall mortality. Microvascular damage is prevalent both in diabetes mellitus (DM) and chronic kidney disease (CKD). Our aim was to compare microcirculatory function parameters in diabetic and non-diabetic CKD patients via nailfold video-capillaroscopy.

METHODS

We included 48 diabetic and 48 non-diabetic adult CKD patients. All participants underwent nailfold video-capillaroscopy, during which capillary density was measured at normal conditions (baseline), after a 4-minute arterial occlusion (postocclusive reactive hyperemia), and at the end of a 2-minute venous occlusion (congestion phase).

RESULTS

Diabetic patients presented significantly lower capillary density during reactive hyperemia (36.3 ± 3.8 vs 38.3 ± 4.3 capillaries/mm² , P = .022) and at venous congestion (37.8 ± 4.0 vs 39.8 ± 4.2 capillaries/mm² , P = .015). When stratified according to CKD stages, only in stage 3b capillary density was significantly lower in diabetic compared to non-diabetic subjects at baseline, during postocclusive hyperemia (36.8 ± 2.7 vs 40.0 ± 4.3 capillaries/mm² , P = .037) and venous congestion (38.3 ± 2.8 vs 41.5 ± 3.5 capillaries/mm² , P = .022).

CONCLUSIONS

Capillary density during postocclusive hyperemia and after venous congestion is lower in diabetic compared to non-diabetic CKD patients, a finding indicative that diabetes is an additional factor contributing to microcirculatory structural and functional impairment in CKD. These differences are more prominent in CKD stage 3b.

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).

Contribution of single office aortic systolic blood pressure measurements to the detection of masked hypertension: data from two separate cohorts

Masked hypertension (MH) and masked uncontrolled hypertension (MUH) remain largely underdiagnosed with no efficient detection algorithm. We recently proposed a novel classification of office systolic hypertension phenotypes defined on the basis of both brachial and aortic systolic blood pressure (bSBP/aSBP) and showed that type III ("isolated high office aSBP" phenotype: normal office bSBP but high office aSBP) has higher hypertension-mediated organ damage (HMOD). We tested whether MH/MUH (1) can be detected with the "isolated high office aSBP" phenotype and (2) if it is associated with elevated office aSBP with respect to normotension. We classified two separate and quite different cohorts (n = 391 and 956, respectively) on the basis of both bSBP and aSBP into four different phenotypes. Participants were classified as sustained hypertensives, masked hypertensives/masked uncontrolled hypertensives (MHs/MUHs), white coat hypertensives, and normotensives according to their office and out-of-office BP readings. The majority (more than 60% in cohort A and more than 50% in cohort B) of type III individuals were MHs/MUHs. Almost 35% of MHs/MUHs had optimal office bSBP rather than high normal bSBP. In both cohorts, the detection of more than 40% of MH/MUH was feasible with the type III phenotype. MHs/MUHs had higher office aSBP than individuals with sustained normotension (p < 0.05). In conclusion, in the absence of an efficient screening test, the diagnosis of MH/MUH can be assisted by the detection of the "isolated high office aSBP" phenotype, which can be measured in a single office visit. MHs/MUHs have increased aSBP relative to normotensives, further explaining the increased mortality of MH/MUH.

Associations of serum sclerostin and Dickkopf-related protein-1 proteins with future cardiovascular events and mortality in haemodialysis patients: a prospective cohort study

Background

Sclerostin and Dickkopf-related protein-1 (Dkk-1) proteins are inhibitors of the canonical Wnt/β-catenin bone pathway. Sclerostin but not Dkk-1 is associated with increased arterial stiffness. This study examined the prognostic significance of sclerostin and Dkk-1 levels for cardiovascular outcomes and mortality in haemodialysis (HD) patients.

Methods

Serum sclerostin and Dkk-1 levels were measured with enzyme-linked immunosorbent assay in 80 HD patients that were followed-up for a median of 45 months. Factors that could interfere with the association of sclerostin and Dkk-1 with outcomes [including carotid–femoral pulse wave velocity (PWV), parathyroid hormone (PTH), calcium–phosphate product and others] were assessed at baseline. The primary endpoint was a combination of all-cause death, non-fatal myocardial infarction, non-fatal stroke, coronary revascularization, hospitalization for decompensated heart failure and new-onset atrial fibrillation. Secondary endpoints included cardiovascular and all-cause mortality.

Results

Cumulative freedom from the primary endpoint was significantly lower for higher tertiles of sclerostin (77.8, 69.2 and 40.7%; Tertiles 1–3, respectively; log-rank P = 0.004). The risk for the primary outcome gradually increased for higher sclerostin tertiles [Tertile 3: hazard ratio (HR) = 3.847, 95% confidence interval (CI) 1.502–9.851]. No significant association was evident between sclerostin and all-cause mortality, whereas higher sclerostin levels presented a trend towards higher risk for cardiovascular mortality. Dkk-1 levels exhibited no association with the risk of the primary or secondary endpoints. In stepwise Cox regression modelled analysis, sclerostin levels were associated with the primary outcome, independently of PTH, calcium–phosphate product, serum albumin, C-reactive protein and PWV levels (HR = 2.921, 95% CI 1.401–6.090; P = 0.004).

Conclusions

High sclerostin levels are associated with lower cumulative freedom and higher risk for a composite endpoint of cardiovascular events and mortality. Dkk-1 exhibited no association with the future risk of adverse outcomes.

A comparative study of ambulatory central hemodynamics and arterial stiffness parameters in peritoneal dialysis and hemodialysis patients

BACKGROUND

Ambulatory pulse-wave velocity (PWV), augmentation pressure, and augmentation index (AIx) are associated with increased cardiovascular events and death in hemodialysis. The intermittent nature of hemodialysis generates a distinct ambulatory pattern, with a progressive increase of augmentation pressure and AIx during the interdialytic interval. No study so far has compared the ambulatory course of central hemodynamics and PWV between peritoneal dialysis and hemodialysis patients.

METHODS

Thirty-eight patients under peritoneal dialysis and 76 patients under hemodialysis matched in a 1 : 2 ratio for age, sex and dialysis vintage underwent 48-h ambulatory blood pressure (BP) monitoring with the oscillometric Mobil-O-Graph device. Parameters of central hemodynamics [central SBP, DBP and pulse pressure (PP)], wave reflection [AIx, heart rate-adjusted AIx; AIx(75) and augmentation pressure] and PWV were estimated from the 48-h recordings.

RESULTS

Over the total 48-h period, no significant differences were observed between peritoneal dialysis and hemodialysis patients in mean levels of central SBP, DBP, PP, augmentation pressure, AIx, AIx(75) and PWV. However, patients under peritoneal dialysis and hemodialysis displayed different trajectories in all the above parameters over the course of the recording: in peritoneal dialysis patients no differences were noted in central SBP (125.0 ± 19.2 vs. 126.0 ± 17.8 mmHg, P = 0.25), DBP, PP, augmentation pressure (13.0 ± 6.8 vs. 13.7 ± 7. mmHg, P = 0.15), AIx(75) (25.9 ± 6.9 vs. 26.3 ± 7.8%, P = 0.54) and PWV (9.5 ± 2.1 vs. 9.6 ± 2.1 m/s, P = 0.27) from the first to the second 24-h period of the recording. In contrast, hemodialysis patients showed significant increases in all these parameters from the first to second 24 h (SBP: 119.5 ± 14.4 vs. 124.6 ± 15.0 mmHg, P < 0.001; augmentation pressure: 10.9 ± 5.3 vs. 13.1 ± 6.3 mmHg, P < 0.001; AIx(75): 24.7 ± 7.6 vs. 27.4 ± 7.9%, P < 0.001; PWV: 9.1 ± 1.8 vs. 9.3 ± 1.8 m/s, P < 0.001). Peritoneal dialysis patients had numerically higher levels than hemodialysis patients in all the above parameters during all periods studied and especially during the first 24-h.

CONCLUSION

Central BP, wave reflection indices and PWV during a 48-h recording are steady in peritoneal dialysis but gradually increase in hemodialysis patients. During all studied periods, peritoneal dialysis patients have numerically higher levels of all studied parameters, a fact that could relate to higher cardiovascular risk.

Relation of protein energy wasting to carotid intima media thickness in hemodialysis patients

Carotid intima media thickness (CIMT) can reflect the degree of atherosclerosis and cardiovascular risk in hemodialysis patients. Factors such as advanced age, male gender, family history, and smoking can increase the risk of CIMT. In hemodialysis (HD) patients, lower serum albumin level was found to be correlated with higher CIMT. This study aimed to evaluate the relation between CIMT and protein energy wasting (PEW) diagnosed according to the diagnostic criteria of International Society of Renal Nutrition and Metabolism (ISRNM) expert panel in HD patients. This study involved 45 HD patients who were divided into two groups according to the diagnostic criteria for PEW proposed by the ISRNM expert panel including group with PEW (11 patients) and group without PEW (34 patients). Caloric intake was evaluated by food frequency questionnaire for 3 days. Subjective global assessment (SGA) and malnutrition inflammation score (MIS) were fulfilled. Anthropometric measurements, as well as body composition, was evaluated by electrical bioimpedance analysis. Doppler ultrasonography was used to assess CIMT that was significantly higher in patients with PEW (p = 0.030). CIMT had significant positive correlation to age, SGA, and MIS (p = 0.008, 0.002, and 0.003, respectively). Significant negative correlation was observed between CIMT and serum albumin. Multiple linear regression analysis revealed that serum albumin was the only predictor of mean CIMT. In conclusion, CIMT seems to be related to malnutrition in HD patients. Low serum albumin was the only predictor of CIMT.

Weak within-individual association of blood pressure and pulse wave velocity in hemodialysis is related to adverse outcomes

OBJECTIVES

Hemodialysis patients have premature arterial stiffness, and the relationship between pulse wave velocity (PWV) and blood pressure (BP) may be different than in other hypertensives. Previous studies in such patients showed that when BP decrease is accompanied by PWV decrease the survival is improved. This study examines the prognostic role of the mean BP (MBP)-PWV association for cardiovascular outcomes and all-cause mortality in hemodialysis.

METHODS

A total of 242 hemodialysis patients underwent 48-h ambulatory BP monitoring with Mobil-O-Graph-NG and were followed for 33.17 ± 19.68 months. The within-individual MBP-PWV association (MBP, dependent and PWV independent variable) was evaluated using the β-coefficient value from simple linear regression analysis for each patient. The primary end-point was first occurrence of all-cause death, nonfatal myocardial infarction or nonfatal stroke. Secondary end-points were all-cause mortality, cardiovascular mortality and a combination of cardiovascular events.

RESULTS

Higher quartiles of β-coefficients (indicating strong within-individual association of MBP with PWV) were related to greater cumulative freedom from the primary end-point (50.8, 60.0, 70.0 and 80.3% for quartiles 1-4, respectively; log-rank P = 0.001), better overall survival (60.7, 61.7, 73.3, 86.9%; log-rank P = 0.002) and better cardiovascular survival (78.7, 75.0, 81.7, 91.8% for quartiles 1-4; log-rank P = 0.044). The future risks of the primary end-point, all-cause and cardiovascular mortality and the combined outcome were progressively increasing with lower quartiles of β-coefficients, indicating patients with weak MBP-PWV association (hazard ratios for all-cause mortality 3.395; 95% confidence interval: 1.524-7.563, P = 0.003 for quartile 1 vs. quartile 4).

CONCLUSION

Weaker within-individual MBP-PWV association, based on ABPM recordings, is associated with higher risk of death and cardiovascular events in hemodialysis. These findings support that arterial stiffness insensitive to BP changes is the underlying factor for adverse outcomes in these individuals.

Reference values of office central blood pressure, pulse wave velocity, and augmentation index recorded by means of the Mobil-O-Graph PWA monitor

Assessment of central blood pressure (BP), pulse wave velocity (PWV), and augmentation index (AIx) measurements may improve cardiovascular risk stratification. This study aimed to establish reference office values for central BP, PWV, and AIx by means of a Mobil-O-Graph PWA monitor and to evaluate the impact of cardiovascular risk factors (CVRFs) on these measurements. We cross-sectionally evaluated clinical characteristics, central BP, PWV, AIx, and peripheral BP measurements among 867 apparently healthy individuals (age = 46.0 ± 15.5 years, 39% males) who were free of obesity, hypertension, active smoking, dyslipidemia, and diabetes (CVRF-No) and 5632 individuals (age = 57.0 ± 14.7 years, 44% males) with at least one of these major CVRFs (CVRF-Yes). Reference values for central BP, PWV, and AIx were provided for the CVRF-No and CVRF-Yes groups, stratified by age and sex. PWV and AIx exhibited curvilinear increases with age, and there was an interaction between age and sex for central systolic BP and PWV in both the CVRF-No and CVRF-Yes groups. The results of a multivariable analysis including the whole sample (n = 6499) showed that obesity had a direct association with central BP, while diabetes was directly related to PWV. In addition, alcohol intake was directly associated with central BP, while performance of physical activity was inversely related to AIx. In conclusion, values of office-measured central BP, PWV, and AIx obtained in an apparently healthy population and in a population with CVRFs are now available according to age and sex and may be useful to build thresholds for use in clinical practice.

A double-blind, randomized, crossover trial protocol of whole hemp seed protein and hemp seed protein hydrolysate consumption for hypertension

BACKGROUND

Primary hypertension accounts for almost 95% of all cases of high blood pressure and is a major modifiable risk factor for cardiovascular diseases. Lifestyle interventions have been shown to prevent hypertension. One of the prominent potential therapeutic lifestyle strategies to prevent or manage hypertension is increasing dietary protein as a macronutrient or as bioactive peptides. An emerging plant-based protein source that may have anti-hypertensive properties is hemp seed.

METHODS/DESIGN

A randomized, double-blind, crossover clinical trial will be conducted on 35 hypertensive participants aged 18-75 years, with a BMI between 18.5 and 40 kg/m², systolic blood pressure (SBP) between 130 and 160 mmHg and diastolic blood pressure (DBP) ≤ 110 mmHg. The trial will be conducted for a period of 22 weeks and will consist of three treatment periods of 6 weeks, separated by 2-week washout periods. The treatments will be consumed twice a day and consist of 25 g casein, hemp seed protein (HSP), or HSP plus HSP hydrolysate (HSP+). The primary outcome of this trial is 24-h SBP, measured on the first day of first phase and the last day of each phase. Office-measured blood pressure, pulse-wave velocity and augmentation index and anthropometrics will be determined at the first and last days of each period. Also, body composition will be assessed by dual x-ray absorptiometry (DXA) scan on the first day of the first phase and within the last 2 days of each treatment period. Blood samples will be collected on the first and last 2 days of each treatment phase whereas urine samples will be collected on the first day of the first phase plus the last day of each phase to be analyzed for specific biomarkers.

DISCUSSION

This trial protocol is designed to evaluate the hypotensive potential of consuming whole HSP, and HSP+, in comparison to casein protein. This study will be the first trial investigating the potential anti-hypertensive benefit of dietary hemp protein plus bioactive peptide consumption in humans.

TRIAL REGISTRATION

National Clinical Trial (NCT), ID: NCT03508895. Registered on 28 June 2018. Retrospectively registered on the publicly accessible Registry Databank at ClinicalTrials.gov (http://ClinicalTrials.gov).

The Manitoba Personalized Lifestyle Research (TMPLR) study protocol: a multicentre bidirectional observational cohort study with administrative health record linkage investigating the interactions between lifestyle and health in Manitoba, Canada

INTRODUCTION

Lifestyle factors, such as diet, physical activity and sleep, are associated with the development of many chronic diseases. The objective of The Manitoba Personalized Lifestyle Research study is to understand how these lifestyle factors interact with each other and with other factors, such as an individual's genetics and gut microbiome, to influence health.

METHODS

An observational study of adults, with extensive phenotyping by objective health and lifestyle assessments, and retrospective assessment of early life experiences, with retrospective and prospective utilisation of secondary data from administrative health records.

STUDY POPULATION

A planned non-random convenience sample of 840 Manitobans aged 30-46 recruited from the general population, stratified by sex (equal men and women), body mass index (BMI; 60% of participants with a BMI>25 kg/m²) and geography (25% from rural areas). These stratifications were selected based on Manitoba demographics.

MEASUREMENTS

Lifestyle factors assessed will include dietary pattern, physical activity, cardiovascular fitness, and sleep. Factors such as medical history, socioeconomic status, alcohol and tobacco consumption, cognition, stress, anxiety, and early life experiences will also be documented. A maternal survey will be performed. Body composition and bone density will be measured by dual energy X-ray absorptiometry. Blood pressure, pulse wave velocity, and augmentation index will be measured on two consecutive days. Chronic disease risk biomarkers will be measured in blood and urine samples. DNA will be extracted for genetic analysis. A faecal sample will be collected for microbiome analysis. Participants may provide their Manitoba personal health information number to link their study data with administrative health records.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the University of Manitoba Health Research Ethics Board (protocol # HS18951; 05/01/2016). Data analysis, release of results and publication of manuscripts are scheduled to start in early 2019. Additional information at www.TMPLR.ca.

TRIAL REGISTRATION NUMBER

NCT03674957; Pre-results.

Effect of Nebivolol and Olmesartan on 24-Hour Brachial and Aortic Blood Pressure in the Acute Stage of Ischemic Stroke

Background

Elevated blood pressure (BP) in the acute phase of ischemic stroke is associated with heightened risk of early disability and death. However, whether BP-lowering in this setting is beneficial and the exact levels at which BP should be targeted remain unclear. This study aimed to evaluate the effect of nebivolol, olmesartan, and no-treatment on 24-hour BP in patients with hypertension during the acute poststroke period.

Methods

In a single-blind fashion, 60 patients with acute ischemic stroke and clinic systolic BP (SBP) 160-220 mmHg were randomized to nebivolol (5 mg/day), olmesartan (20 mg/day), or no-treatment between Day 4 and Day 7 of stroke onset. BP-lowering efficacy was assessed through 24-hour BP monitoring using the Mobil-O-Graph device (IEM, Germany).

Results

Between baseline and Day 7, significant reductions in 24-hour brachial SBP were noted with nebivolol and olmesartan, but not with no-treatment. Change from baseline (CFB) in 24-hour brachial SBP was not different between nebivolol and olmesartan groups (between-group difference: -3.4 mmHg; 95% confidence interval (CI): -11.2, 4.3), whereas nebivolol was superior to no-treatment in lowering 24-hour brachial SBP (between-group difference: -7.8 mmHg; 95% CI: -7.8 mmHg; 95% CI: -15.6, -0.1). Similarly, nebivolol and olmesartan equally lowered 24-hour aortic SBP (between-group difference: -1.9 mmHg; 95% CI: -10.1, 6.2). Nebivolol and olmesartan provoked similar reductions in 24-hour heart rate-adjusted augmentation index and pulse wave velocity.

Conclusion

This study suggests that during the acute phase of ischemic stroke, nebivolol is equally effective with olmesartan in improving 24-hour aortic pressure and arterial stiffness indices. ClinicalTrials.gov identifier number: NCT03655964.

Nondipping heart rate and associated factors in patients with chronic kidney disease

BACKGROUND

Nondipping heart rate (NHR) is a condition reported to be associated with cardiovascular events and cardiovascular mortality recently. We aimed to search whether there is difference among hypertensive patients with and without chronic kidney disease (CKD) in terms of NHR pattern and the factors associated with NHR in patients with CKD.

METHODS

The study included 133 hypertensive patients with normal kidney functions, 97 hypertensive patients with predialysis CKD, and 31 hypertensive hemodialysis patients. Heart rate, blood pressure and pulse wave velocity (PWV) were measured by 24-h ambulatory blood pressure monitorization. NHR was defined as a decrease of less than 10% at night mean heart rate when compared with daytime values.

RESULTS

NHR pattern was established as 26.3% in non-CKD hypertensive group, 43.3% in predialysis group and 77.4% in dialysis group. Among patients with CKD, when NHR group was compared with dipper heart rate group, it was seen that they were at older age, there were higher prevalence of diabetes mellitus and more female sex, and while the value of urea, creatinine, phosphorus, intact parathyroid hormone, and PWV were significantly higher, the value of hemoglobin, albumin and calcium were significantly lower. By multivariate analysis, hemoglobin [odds ratio (OR) 0.661; 95% CI 0.541-0.806; p < 0.001] and PWV (OR 1.433; 95% CI 1.107-1.853; p = 0.006) were established as independent determinants of NHR pattern.

CONCLUSIONS

NHR pattern is significantly more frequently seen in hypertensive CKD patients than in hypertensive patients with non-CKD. Anemia and increased arterial stiffness are seen independently associated with NHR in CKD patients.

Lung Ultrasound-Guided Dry-Weight Reduction in Hemodialysis Patients Does Not Affect Short-Term Blood Pressure Variability

BACKGROUND

Increased short-term blood pressure (BP) variability (BPV) in hemodialysis is associated with increased cardiovascular and all-cause mortality. Studies on the impact of BP-lowering interventions on BPV are scarce. This study examined the effect of dry-weight reduction with a lung ultrasound-guided strategy on short-term BPV in hemodialysis patients with hypertension.

METHODS

This is a prespecified analysis of a randomized clinical trial in 71 hemodialysis patients with hypertension, assigned in a 1:1 ratio in the active group, following a strategy for dry-weight reduction guided by pre-hemodialysis lung ultrasound and the control group following standard-of-care treatment. All patients underwent 48-hour ambulatory BP monitoring at baseline and after 8 weeks. BPV was calculated with validated formulas for the 48-hour interval and the 2 daytime and nighttime periods.

RESULTS

Dry-weight changes were -0.71 ± 1.39 in active vs. +0.51 ± 0.98 kg in the control group (P < 0.001), generating a between-group difference of 5.9/3.5 mm Hg (P < 0.05) in 48-hour BP at study end. All brachial BPV indices [SD, weighted SD, coefficient of variation, and average real variability (ARV)] did not change significantly from baseline to study end in the active [systolic blood pressure (SBP)-ARV: 12.58 ± 3.37 vs. 11.91 ± 3.13, P = 0.117; diastolic blood pressure (DBP)-ARV: 9.14 ± 1.47 vs. 8.80 ± 1.96, P = 0.190] or control (SBP-ARV: 11.33 ± 2.76 vs. 11.07 ± 2.51, P = 0.544; DBP-ARV: 8.38 ± 1.50 vs. 8.15 ± 1.49, P = 0.295) group (between-group comparison P = 0.211/0.117). Aortic BPV indices followed a similar pattern. Likewise, no significant changes in BPV indices for the daytime and nighttime periods were noted in both groups during follow-up.

CONCLUSIONS

This study is the first to evaluate the effects of a nonpharmacological intervention on short-term BPV in hemodialysis, showing no effect of dry-weight reduction on BPV, despite BP decrease.

Soluble Klotho is associated with mortality and cardiovascular events in hemodialysis

Background

Klotho is a transmembrane protein acting as a co-receptor for FGF-23 and thus exerts clinical actions on mineral metabolism. The association of secreted Klotho with outcomes in CKD patients is unclear. This study examined the relation between plasma Klotho and cardiovascular events in dialysis patients, accounting for common and CKD-MBD related risk factors, arterial stiffness and atherosclerotic burden.

Methods

Seventy-nine chronic hemodialysis patients were observed for a median follow-up of 5.5 years. Klotho levels as well as carotid–femoral pulse wave velocity (cfPWV) and common carotid intima-media thickness (ccIMT) measurements were performed at baseline. The primary end-point was first occurrence of all-cause death, non-fatal myocardial infarction or non-fatal stroke. Secondary end-points were: (i) all-cause mortality; (ii) cardiovascular mortality; (iii) a combination of cardiovascular death, non-fatal MI, non-fatal stroke, resuscitation after cardiac arrest, coronary revascularization, heart failure hospitalization and atrial fibrillation.

Results

Cumulative freedom from the primary endpoint was 31% for the low-Klotho group (≤745 pg/ml) and 53% for the high-Klotho group (logrank p = 0.017); HR: 2.137, 95%CI 1.124–4.065. Cumulative survival was insignificantly lower (44% vs 56%, p = 0.107), but cumulative cardiovascular survival (63% vs 88%, p = 0.029) and cumulative freedom from the cardiovascular composite outcome (18% vs 45%, p = 0.009) were significantly lower in the low-Klotho group. In modelled Cox-regression analysis the association of low Klotho with the primary endpoint remained significant after stepwise adjustment for cFGF3, PTH, Ca x P product, established risk factors (age, dialysis vintage, diabetes, hypertension, smoking, history of cardiovascular disease) as well as cfPWV and ccIMT [Model 6: HR:2.759, 95%CI 1.223–6.224, p = 0.014].

Conclusions

Low Klotho is associated with cardiovascular events in hemodialysis patients, independently from factors associated with mineral-bone disease, common risk factors and intermediate outcomes, such as cfPWV and ccIMT.

Pulse Wave Velocities Derived From Cuff Ambulatory Pulse Wave Analysis

Pulse wave velocity (PWV), a measure of arterial stiffness, is an independent risk factor for cardiovascular morbidity and mortality. We investigated the relationship of ambulatory brachial cuff-based oscillometric PWV (oPWV) to 2 known correlates: age and brachial systolic blood pressure (SBP). In 234 participants in the Masked Hypertension Study, we analyzed 7284 validated hourly ambulatory SBP and oPWV readings using the Mobil-O-Graph monitor, which uses a proprietary pulse wave analysis algorithm to determine oPWV. Carotid-femoral PWV (cfPWV) was also measured. Mixed linear models were developed to estimate oPWV from age and ambulatory SBP. Participants were 34% male, with mean (SD) age 52.8 (9.9) years, SBP 123.8 (18.4) mm Hg, and oPWV 7.6 (1.3) m/s and cfPWV of 7.7 (1.7) m/s. The relationship of oPWV to age and SBP is given below: [Formula: see text] Age uniquely accounted for an estimated 75% of the total variation of oPWV, whereas SBP uniquely accounted for 20%; these findings were confirmed in an external validation dataset. Together, age and SBP accounted for 99.1% of the total variance of oPWV but (only) 40.2% of the variance of cfPWV. The correlation between oPWV and cfPWV was 0.58 but was only 0.11 after controlling for age and SBP. We conclude that the Mobil-O-Graph's oPWV is nearly completely explained by age and SBP and its relationship to cfPWV is because of their shared associations with age and SBP. Other hemodynamic variables derived from oscillometric pulse wave analysis may be useful and deserve additional scrutiny.

Arterial Stiffness in Patients With Renal Transplantation; Associations With Co-morbid Conditions, Evolution, and Prognostic Importance for Cardiovascular and Renal Outcomes

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), are at increased risk of cardiovascular events and mortality. The spectrum of arterial remodeling in CKD and ESRD includes atheromatosis of middle-sized conduit arteries and, most importantly, the process of arteriosclerosis, characterized by increased arterial stiffness of aorta and the large arteries. Longitudinal studies showed that arterial stiffness and abnormal wave reflections are independent cardiovascular risk factors in several populations, including patients with CKD and ESRD. Kidney transplantation is the treatment of choice for patients with ESRD, associated with improved survival and better quality of life in relation to hemodialysis or peritoneal dialysis. However, cardiovascular mortality in transplanted patients remains much higher than that in general population, a finding that is at least partly attributed to adverse lesions in the vascular tree of these patients, generated during the progression of CKD, which do not fully reverse after renal transplantation. This article attempts to provide an overview of the field of arterial stiffness in renal transplantation, discussing in detail available studies on the degree and the associations of arterial stiffness with other co-morbidities in renal transplant recipients, the prognostic significance of arterial stiffness for cardiovascular events, renal events and mortality in these individuals, as well as studies examining the changes in arterial stiffness following renal transplantation.

Pulse wave analysis using the Mobil-O-Graph, Arteriograph and Complior device: a comparative study

PURPOSE

Pulse wave velocity (PWV) is a marker of arterial stiffness with major prognostic value. We compared Arteriograph and Complior devices with the Mobil-O-Graph for assessment of PWV and central systolic blood pressure (cSBP).

MATERIALS AND METHODS

We studied 316 consecutive subjects (age: 55 ± 14 years). For each individual, we measured PWV and cSBP with Arteriograph, Complior and Mobil-O-Graph and compared the readings. Differences in values among three devices were calculated for each measurement. We used Bland-Altman analysis, intraclass correlation coefficient (ICC) and coefficient of variation (CV).

RESULTS

Bland-Altman analysis indicated a mean difference for PWV: i.0.5 m/s (limits of agreement -1.4-2.4) between Complior and Mobil-O-Graph, ii.0.6 m/s (limits of agreement -1.4-2.6) between Arteriograph and Mobil-O-Graph. cSBP mean difference was 3.8 mmHg between Complior and Mobil-O-Graph (limits of agreement -12.5-20.1) and 9.2 mmHg between Arteriograph and Mobil-O-Graph (limits of agreement -7.6-26). ICC for PWV was 0.86 between Arteriograph and Mobil-O-Graph, 0.87 between Complior and Mobil-O-Graph and for cSBP 0.92 and 0.91 respectively. CV for PWV was 9.5% between Arteriograph and Mobil-O-Graph, 8.8% between Complior and Mobil-O-Graph. Respective values for cSBP were 6.8% and 5.1%.

CONCLUSION

Our study shows acceptable agreement among the three devices regarding pulse wave analysis markers though Mobil-O-Graph appears to underestimate the values of these markers. Further studies are needed to explore the agreement between the 3 devices in various clinical settings and patient populations.

Arterial stiffness in black African ancestry patients with chronic kidney disease living in Cameroon

Background

Increased aortic pulse wave velocity (PWV), a direct measure of arterial stiffness (AS) is an independent predictor of cardiovascular events (CVEs) in chronic kidney disease (CKD) patients. This study assessed the patterns of PWV among Cameroonian patients with CKD in whom that marker of early vascular aging has not been explored so far.

Methods

We enrolled 150 Black African patients (mean age: 52±15 years, 56.7% males) with CKD in a cross-sectional study conducted at Douala General Hospital, Douala, Cameroon. Sociodemographic, anthropometric and biologic variables, blood pressure (BP) and PWV were recorded in all participants. Estimated aortic PWV was measured using a Mobil-O-Graph automatic brachial oscillometric device.

Results

PWV increased with aging (P<0.0001), and PWV adjusted for age, sex, body mass index and mean arterial BP (MAP) was higher in non-dialysed (n=90) than in hemodialysed (n=60) patients, even in pre-dialysis: 8.5±2.0 vs. 7.9±1.4 m/s (P=0.026); and in post-dialysis: 8.5±2.0 vs. 7.8±1.5 m/s (P=0.008). The mean PWV of all study participants was 8.2±1.8 m/s, with 61.3% of patients having a PWV ≥8.2 m/s, indicative of subclinical damage to the aorta, which was more pronounced in non-dialysis (67.8%) than in hemodialysis (53.3%) patients (P=0.033). Multivariable analysis performed in all participants revealed that advanced age, MAP and tobacco use were independently associated with PWV (all P<0.05).

Conclusions

Our findings suggest increased AS in Cameroonian CKD non-dialyzed as compared to dialyzed patients. Slower PWV in patients on maintenance hemodialysis suggests improvement of aortic distensibility following dialysis. However, further large-scale studies are needed to confirm our findings and to improve understanding of the underlying mechanisms of arterial stiffening in black African ancestry patients with CKD.

Association of Ambulatory Blood Pressure with All-Cause and Cardiovascular Mortality in Hemodialysis Patients: Effects of Heart Failure and Atrial Fibrillation

BACKGROUND

Evidence on the utility of ambulatory BP monitoring for risk prediction has been scarce and inconclusive in patients on hemodialysis. In addition, in cardiac diseases such as heart failure and atrial fibrillation (common among patients on hemodialysis), studies have found that parameters such as systolic BP (SBP) and pulse pressure (PP) have inverse or nonlinear (U-shaped) associations with mortality.

METHODS

In total, 344 patients on hemodialysis (105 with atrial fibrillation, heart failure, or both) underwent ambulatory BP monitoring for 24 hours, starting before a dialysis session. The primary end point was all-cause mortality; the prespecified secondary end point was cardiovascular mortality. We performed linear and nonlinear Cox regression analyses for risk prediction to determine the associations between BP and study end points.

RESULTS

During the mean 37.6-month follow-up, 115 patients died (47 from a cardiovascular cause). SBP and PP showed a U-shaped association with all-cause and cardiovascular mortality in the cohort. In linear subgroup analysis, SBP and PP were independent risk predictors and showed a significant inverse relationship to all-cause and cardiovascular mortality in patients with atrial fibrillation or heart failure. In patients without these conditions, these associations were in the opposite direction. SBP and PP were significant independent risk predictors for cardiovascular mortality; PP was a significant independent risk predictor for all-cause mortality.

CONCLUSIONS

This study provides evidence for the U-shaped association between peripheral ambulatory SBP or PP and mortality in patients on hemodialysis. Furthermore, it suggests that underlying cardiac disease can explain the opposite direction of associations.

Arterial stiffness in end-stage renal disease-pathogenesis, clinical epidemiology, and therapeutic potentials

Arterial stiffness is an important risk factor for cardiovascular morbidity and mortality in patients with end-stage renal disease (ESRD). Arterial stiffness aggravates cardiovascular risk via multiple pathways, such as augmentation of aortic systolic pressure, subendocardial hypoperfusion, and excess pulsatile energy transmission from macro- to microcirculation. Pathogenesis of the arteriosclerotic process in ESRD is complex and not yet fully understood. Several factors unique to ESRD, such as mineral metabolism disturbances, vascular calcifications, formation of advanced glycation end-products, and acute and chronic volume overload, are proposed to play a particular role in the progression of arteriosclerosis in ESRD. As these and other mechanistic pathways of arterial stiffening in ESRD are elucidated, there is hope that this knowledge will be translated into novel therapeutic interventions targeting arterial stiffness. In the meantime, blood pressure (BP) lowering via strict volume control and appropriate use of antihypertensive drugs is a fundamental step in reversing accelerated arterial stiffening and modifying the cardiovascular risk profile of ESRD patients. In this article, we review the pathogenesis, clinical epidemiology, and therapies targeting arterial stiffness in ESRD, discussing recent advances and high-priority goals of future research in these important areas.

The evaluation of arterial stiffness of essential hypertension and white coat hypertension in children: a case-control study

BACKGROUND

The aim of this study was to determine and compare cardiovascular risks by assessing arterial stiffness in children with essential hypertension and white coat hypertension.

METHODS

Paediatric patients followed up with essential hypertension and white coat hypertension diagnoses and with no established end organ damage were involved in the study. Arterial stiffness in children included in the study was evaluated and compared by using the oscillometric device (Mobil-O-Graph) method.

RESULTS

A total of 62 essential hypertension (34 male, 28 female), 38 white coat hypertension (21 male, 17 female), and 60 healthy controls (33 male, 27 female) were assessed in the present study. Pulse wave velocity of the essential hypertension, white coat hypertension, and control group was, respectively, as follows: 5.3±0.6 (m/s), 5.1±0.4 (m/s), 4.3±0.4 (m/s) (p<0.001); augmentation index outcomes were, respectively, determined as follows: 21.3±6.5, 19.3±6.4, 16.0±0.3 (p<0.001). Pulse wave velocity and augmentation index values of children with essential hypertension and white coat hypertension were found to be higher compared with the control group. This level was identified as correlated with the duration of hypertension in both patient groups (p<0.01).

CONCLUSION

Arterial stiffness in children with essential hypertension and white coat hypertension was impaired compared with healthy children. This finding has made us think that white coat hypertension is not an innocent clinical situation. This information should be taken into consideration in the follow-up and treatment approaches of the patients.

Twenty-Four-Hour Ambulatory Pulse Wave Analysis in Hypertension Management: Current Evidence and Perspectives

The predictive value of vascular biomarkers such as pulse wave velocity (PWV), central arterial pressure (CAP), and augmentation index (AIx), obtained through pulse wave analysis (PWA) in resting conditions, has been documented in a variety of patient groups and populations. This allowed to make appropriate recommendations in clinical practice guidelines of several scientific societies. Due to advances in technologies, largely operator-independent methods are currently available for estimating vascular biomarkers also in ambulatory conditions, over the 24 h. According to the acceptable accuracy and reproducibility of 24-h ambulatory PWA, it appears to be a promising tool for evaluating vascular biomarkers in daily life conditions. This approach may provide an opportunity to further improve the early cardiovascular screening in subjects at risk. However, concerning the clinical use of PWA over the 24 h in ambulatory conditions at the moment, there is no sufficient evidence to support its routine clinical use. In particular, long-term outcome studies are needed to show the predictive value of 24-h PWV, CAP, and AIx values, provided by these devices, over and beyond peripheral blood pressure, and to answer the many technical and clinical questions still open. To this regard, the VASOTENS Registry, an international observational prospective study recently started, will help providing answers on a large sample of hypertensive patients recruited worldwide.

Ambulatory Pulse Wave Velocity Is a Stronger Predictor of Cardiovascular Events and All-Cause Mortality Than Office and Ambulatory Blood Pressure in Hemodialysis Patients

Arterial stiffness and augmentation of aortic blood pressure (BP) measured in office are known cardiovascular risk factors in hemodialysis patients. This study examines the prognostic significance of ambulatory brachial BP, central BP, pulse wave velocity (PWV), and heart rate-adjusted augmentation index [AIx(75)] in this population. A total of 170 hemodialysis patients underwent 48-hour ambulatory monitoring with Mobil-O-Graph-NG during a standard interdialytic interval and followed-up for 28.1±11.2 months. The primary end point was a combination of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. Secondary end points included: (1) all-cause mortality; (2) cardiovascular mortality; and (3) a combination of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, coronary revascularization, or hospitalization for heart failure. During follow-up, 37(21.8%) patients died and 46(27.1%) had cardiovascular events. Cumulative freedom from primary end point was similar for quartiles of predialysis-systolic BP (SBP), 48-hour peripheral-SBP, and central-SBP, but was progressively longer for increasing quartiles for 48-hour peripheral-diastolic BP and central-diastolic BP and shorter for increasing quartiles of 48-hour central pulse pressure (83.7%, 71.4%, 69.0%, 62.8% [log-rank P=0.024]), PWV (93.0%, 81.0%, 57.1%, 55.8% [log-rank P<0.001]), and AIx(75) (88.4%, 66.7%, 69.0%, 62.8% [log-rank P=0.014]). The hazard ratios for all-cause mortality, cardiovascular mortality, and the combined outcome were similar for quartiles of predialysis-SBP, 48-hour peripheral-SBP, and central-SBP, but were increasing with higher ambulatory PWV and AIx(75). In multivariate analysis, 48-hour PWV was the only vascular parameter independently associated with the primary end point (hazard ratios, 1.579; 95% confidence intervals, 1.187-2.102). Ambulatory PWV, AIx(75), and central pulse pressure are associated with increased risk of cardiovascular events and mortality, whereas office and ambulatory SBP are not. These findings further support that arterial stiffness is the prominent cardiovascular risk factor in hemodialysis.

Estimated Pulse Wave Velocity Calculated from Age and Mean Arterial Blood Pressure

In a recently published paper, Greve et al [J Hypertens 2016;34:1279-1289] investigate whether the estimated carotid-femoral pulse wave velocity (ePWV), calculated using an equation derived from the relationship between carotid-femoral pulse wave velocity (cfPWV), age, and blood pressure, predicts cardiovascular disease (CVD) as good as the measured cfPWV. Because ePWV predicts CVD as good as cfPWV, some might wonder whether ePWV could be replaced by cfPWV, which is a time-consuming measurement requiring an expensive apparatus. This question is addressed in this mini-review.

Rationale and study design of the prospective, longitudinal, observational cohort study "rISk strAtification in end-stage renal disease" (ISAR) study

Background

The ISAR study is a prospective, longitudinal, observational cohort study to improve the cardiovascular risk stratification in endstage renal disease (ESRD). The major goal is to characterize the cardiovascular phenotype of the study subjects, namely alterations in micro- and macrocirculation and to determine autonomic function.

Methods/design

We intend to recruit 500 prevalent dialysis patients in 17 centers in Munich and the surrounding area. Baseline examinations include: (1) biochemistry, (2) 24-h Holter Electrocardiography (ECG) recordings, (3) 24-h ambulatory blood pressure measurement (ABPM), (4) 24 h pulse wave analysis (PWA) and pulse wave velocity (PWV), (5) retinal vessel analysis (RVA) and (6) neurocognitive testing. After 24 months biochemistry and determination of single PWA, single PWV and neurocognitive testing are repeated. Patients will be followed up to 6 years for (1) hospitalizations, (2) cardiovascular and (3) non-cardiovascular events and (4) cardiovascular and (5) all-cause mortality.

Discussion/conclusion

We aim to create a complex dataset to answer questions about the insufficiently understood pathophysiology leading to excessively high cardiovascular and non-cardiovascular mortality in dialysis patients. Finally we hope to improve cardiovascular risk stratification in comparison to the use of classical and non-classical (dialysis-associated) risk factors and other models of risk stratification in ESRD patients by building a multivariable Cox-Regression model using a combination of the parameters measured in the study.

Clinical trials identifier

ClinicalTrials.gov NCT01152892 (June 28, 2010)

Haemodialysis and haemodiafiltration lead to similar changes in vascular stiffness during treatment

BACKGROUND

Haemodiafiltration (HDF) has been reported to cause less hypotension than haemodialysis (HD). We hypothesized that HDF causes less change in vascular tone, thereby reducing hypotension.

METHODS

Aortic pulse wave velocity (PWVao) was measured in 284 patients, during a single dialysis session using cooled dialysate (117 HD, 177 HDF). Patient groups were matched for age, sex and cardiovascular comorbidity.

RESULTS

Systolic blood pressure (SBP) declined from 144 ± 26 to 133 ± 26 after 20 minutes, and to 131 ± 26 mmHg post HD, and for HDF from 152 ± 26 to 143 ± 27 after 20 minutes, then to 138 ± 27 mmHg post HDF. Net Ultrafiltration rates to achieve weight loss were similar; HD 0.13 ± 0.06 vs HDF 0.12 ± 0.05 mL/kg/min. PWVao did not change after 20 minutes HD 0.42(-0.7 to 1.3), HDF 0.5 (-0.6 to 1.8) or at the end of the session: HD -0.39 (1.5 to 1.2), HDF -0.41(-2.0 to 1.3) m/s. Aortic augmentation index (AiAxo), assessment of vascular tone fell significantly with both HD; 20 minutes by 6.2 (-2.5 to 14), end 5.6 (-6.7 to 13.9), and HDF 20 min by 4.2 (-2.5 to 10), end 7.8 (-0.8 to 19.3), with no difference between HD and HDF. The ultrafiltration rate correlated with % change in aortic SBP (r = 0.28 p = 0.004), but not with changes in PWVao or augmentation indices.

CONCLUSIONS

Blood pressure declined during both HD and HDF treatments, as did augmentation indices, unrelated to weight loss, suggesting a reduction in vascular stiffness occurs independently of treatment modality. We did not observe an advantage for HDF.