The association of home blood pressure with all-cause mortality in hemodialysis patients: A prospective observational study

INTRODUCTION

Prior observational studies conducted in the hemodialysis population have suggested a reverse association between dialysis-unit blood pressure (BP) and mortality. The present study aimed to investigate the prognostic association of home versus dialysis-unit BP with all-cause mortality in hemodialysis patients.

METHODS

At baseline, 146 patients receiving maintenance hemodialysis underwent assessment of their BP with the following methods: (i) 2-week averaged routine predialysis and postdialysis BP measurements; (ii) home BP monitoring for 1 week that included duplicate morning and evening BP measurements with the use of validated devices.

RESULTS

Over a median follow-up period of 38 months (interquartile range [IQR]: 22-54), 44 patients (31.1%) died. In Kaplan-Meier curves, predialysis and postdialysis systolic BP (SBP) was not associated with all-cause mortality, while home SBP appeared to be of prognostic significance (log rank p = 0.029). After stratifying patients into quartiles, all-cause mortality was lowest when home SBP was ranging from 128.1 to 136.8 mmHg (quartile 2). In univariate Cox regression analysis, using quartile 2 as a referent category, the risk of all-cause mortality was 3.32-fold higher in quartile 1, 1.53-fold higher in quartile 3 and 3.25-fold higher in quartile 4. The risk-association remained unchanged after adjustment for several confounding factors (adjusted hazard ratio: 4.79, 1.79, 3.63 for quartiles 1, 3, and 4 of home systolic BP, respectively).

CONCLUSION

Our findings suggest that among hemodialysis patients, 1-week averaged home SBP is independently associated with all-cause mortality. In sharp contrast, SBP recorded either before or after dialysis over 2 weeks is not prognostically informative.

Gender-Related Differences in the Levels of Ambulatory BP and Intensity of Antihypertensive Treatment in Patients Undergoing Peritoneal Dialysis

Prior studies have shown that among patients with chronic kidney disease not yet on dialysis, the faster progression of kidney injury in men than in women is, at least partly, explained by sex differences in ambulatory blood pressure (BP) control. The present study aimed to investigate potential differences in the levels of ambulatory BP and intensity of antihypertensive treatment between men and women with end-stage kidney disease undergoing long-term peritoneal dialysis (PD). In a case-control design, 48 male PD patients were matched for age and heart failure status with 48 female patients in a 1:1 ratio. Ambulatory BP monitoring was performed with an oscillometric device, the Mobil-O-Graph (IEM, Stolberg, Germany). The BP-lowering medications actually taken by the patients were prospectively recorded. No gender-related differences were observed in 24 h systolic BP (129.0 ± 17.9 vs. 128.5 ± 17.6 mmHg, p = 0.890). In contrast, 24 h diastolic BP was higher in men than in women (81.5 ± 12.1 vs. 76.8 ± 10.3 mmHg, p = 0.042). As compared with women, men were being treated with a higher average number of antihypertensive medications daily (2.4 ± 1.1 vs. 1.9 ± 1.1, p = 0.019) and were more commonly receiving calcium-channel-blockers (70.8% vs. 43.8%, p = 0.007) and β-blockers (85.4% vs. 66.7%, p = 0.031). In conclusion, the present study shows that among PD patients, the levels of ambulatory BP and intensity of antihypertensive treatment are higher in men than in women. Longitudinal studies are needed to explore whether these gender-related differences in the severity of hypertension are associated with worse cardiovascular outcomes for male patients undergoing PD.

Effect of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers on cardiovascular outcomes in dialysis patients: a systematic review and meta-analysis

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs) are recommended by guidelines as first-line antihypertensive therapies in the general population or in patients with earlier stages of kidney disease. However, the cardioprotective benefit of these agents among patients on dialysis remains uncertain.

METHODS

We searched the MEDLINE, PubMed and Cochrane databases from inception through February 2022 to identify randomized controlled trials (RCTs) comparing the efficacy of ACEIs/ARBs relative to placebo or no add-on treatment in patients receiving dialysis. RCTs were eligible if they assessed fatal or non-fatal cardiovascular events as a primary efficacy endpoint.

RESULTS

We identified five RCTs involving 1582 dialysis patients. Compared with placebo or no add-on treatment, the use of ACEIs/ARBs was not associated with a significantly lower risk of cardiovascular events {risk ratio [RR] 0.79 [95% confidence interval (CI) 0.57-1.11]}. Furthermore, there was no benefit in cardiovascular mortality [RR 0.82 (95% CI 0.59-1.14)] and all-cause mortality [RR 0.86 (95% CI 0.64-1.15)]. These results were consistent when the included RCTs were stratified by subgroups, including hypertension, ethnicity, sample size, duration of follow-up and quality.

CONCLUSION

The present meta-analysis showed that among patients on dialysis, the use of ACEIs/ARBs is not associated with a significantly lower risk of cardiovascular events and all-cause mortality as compared with placebo or no add-on treatment.

Hypertension in Dialysis Patients: Diagnostic Approaches and Evaluation of Epidemiology

Whereas hypertension is an established cardiovascular risk factor in the general population, the contribution of increased blood pressure (BP) to the huge burden of cardiovascular morbidity and mortality in patients receiving dialysis continues to be debated. In a large part, this controversy is attributable to particular difficulties in the accurate diagnosis of hypertension. The reverse epidemiology of hypertension in dialysis patients is based on evidence from large cohort studies showing that routine predialysis or postdialysis BP measurements exhibit a U-shaped or J-shaped association with cardiovascular or all-cause mortality. However, substantial evidence supports the notion that home or ambulatory BP measurements are superior to dialysis-unit BP recordings in diagnosing hypertension, in detecting evidence of target-organ damage and in prognosticating the all-cause death risk. In the first part of this article, we explore the accuracy of different methods of BP measurement in diagnosing hypertension among patients on dialysis. In the second part, we describe how the epidemiology of hypertension is modified when the assessment of BP is based on dialysis-unit versus home or ambulatory recordings.

Prevalence of Apparent Treatment-Resistant Hypertension in ESKD Patients Receiving Peritoneal Dialysis

BACKGROUND

Apparent treatment-resistant hypertension (aTRH) is defined as failure to achieve adequate blood pressure (BP) control despite taking ≥3 antihypertensive medications from different categories or when taking ≥4 antihypertensives regardless of BP levels.

METHODS

In this cross-sectional study, we estimated the prevalence of aTRH in 140 patients receiving long-term peritoneal dialysis (PD) in four centers of Northern Greece, using the "gold-standard" method of ambulatory BP monitoring for the assessment of BP control status. The presence of subclinical overhydration was evaluated with the method of bioimpedance spectroscopy (BIS).

RESULTS

Incorporating the diagnostic threshold of 130/80 mmHg for 24-hour ambulatory BP, the prevalence of aTRH in the overall study population was 30%. Compared to patients without aTRH, those with aTRH tended to be older in age, had higher PD vintage, had higher dialysate-to-plasma creatinine ratio, had more commonly history of diabetes mellitus, and were more commonly current smokers. With respect to the volume status, the overhydration index in BIS was higher in those with versus without aTRH (2.0 ± 1.9 L vs. 1.1 ± 2.0 L, P < 0.05). The prevalence of volume overload, defined as an overhydration index in BIS > 2.5 L, was also higher in the subgroup of patients with aTRH (38.1% vs. 18.4, P = 0.01).

CONCLUSION

The present study showed that among patients on PD, the prevalence of aTRH was 30%. However, 38% of PD patients with aTRH had subclinical overhydration in BIS, suggesting that the achievement of adequate volume control may be a therapeutic opportunity to improve the management of hypertension in this high-risk patient population.The present study showed that among patients on PD, the prevalence of aTRH was 30%. However, 38% of PD patients with aTRH had subclinical overhydration in BIS, suggesting that the achievement of adequate volume control may be a therapeutic opportunity to improve the management of hypertension in this high-risk patient population.

CLINICAL TRIALS REGISTRATION

Trial Number NCT03607747.

MO879: Prevalence, Recurrence and Seasonal Variation of Hyperkalaemia in Patients Receiving Thrice-Weekly Haemodialysis

BACKGROUND AND AIMS

Prospective cohort studies have shown that among patients on haemodialysis, hyperkalaemia is strongly associated with excess risk for cardiovascular-related hospitalizations and sudden cardiac death [1–4]. However, the actual burden of hyperkalaemia, the rates of its recurrence and seasonality in its variation still remain unclear.

METHOD

Between June 2020 and May 2021, 1786 mid-week predialysis serum potassium (sK) measurements were retrospectively recorded from 149 patients receiving thrice-weekly haemodialysis in a single-centre in Thessaloniki, Greece. The prevalence, recurrence and seasonal variation of hyperkalaemia were assessed using three prespecified sK thresholds (≥5.1, ≥5.5 and ≥ 6.0 mmol/L).

RESULTS

At baseline (June 2020), 60.4%, 42.2% and 13.4% of patients had sK levels ≥ 5.1, ≥5.5 and ≥ 6.0 mmol/L, respectively. At any time-point during the 1-year-long follow-up, 85.2%, 69.8% and 38.9% of patients experienced at least 1 hyperkalaemic episode at the sK threshold of ≥ 5.1, ≥5.5 and ≥ 6.0 mmol/L, respectively. Of the 104 patients experiencing an initial sK elevation ≥ 5.5 mmol/L, hyperkalaemia at the same threshold reoccurred in 60.6% at month-1, in 47.1% at month-2 and in 46.1% at month-3 of follow-up. Seasonal variation was also observed, with the prevalence of hyperkalaemia to be significantly higher in summer. In multivariate logistic regression analysis, shorter delivered haemodialysis &lt; 4 h/session {odds ratio (OR): 2.568; [95% confidence interval (95% CI): 1.045–6.313]} and the use of a high versus a low K concentration in the dialysate (OR: 14.646; 95% CI: 2.727–78.647) were the two factors that were associated with a significantly higher odds of hyperkalaemia at any time-point of the follow-up period.

CONCLUSION

The present study shows that among patients receiving conventional thrice-weekly haemodialysis, the rates of hyperkalaemia prevalence and recurrence are very high, reflecting the large unmet need to identify more effective potassium-lowering therapeutic interventions in this high-risk population.

MO908: The Impact of The COVID-19 Pandemic on Hospitalization Rate of Patients With ESKD in a Tertiary University Hospital of Thessaloniki, Greece

BACKGROUND AND AIMS

During the coronavirus disease-2019 (COVID-19) pandemic, the National Healthcare System of Greece was reorganized in order to cover the expected rise in hospitalizations of critically ill patients with COVID-19 infection. Accordingly, the aim of the present study was to explore whether the onset of the pandemic influenced the hospitalization rate of patients with end-stage kidney disease (ESKD) in a large tertiary university hospital in the metropolitan region of Thessaloniki, Greece.

METHOD

In this observational study, we retrospectively collected data regarding the hospitalizations of ESKD patients in the section of Nephrology of the first Department of Internal Medicine at the AHEPA University Hospital of Thessaloniki. We provide a comparative evaluation of the number of hospitalizations, demographic characteristics of patients and in-hospital outcomes between the 1-year-long period before (1 March 2019–29 February 2020) and the corresponding period after the onset of the COVID-19 pandemic (1 March 2020–28 February 2021).

RESULTS

Over the 1-year period before the onset of the pandemic, 149 ESKD patients with various complications were hospitalized in our department. During the control period, we recorded only 90 non-COVID-19 hospitalizations of ESKD patients (Table 1). There was no significant difference in the age and gender of patients who were hospitalized before and after the onset of the pandemic. Furthermore, the median duration of hospitalizations and the in-hospital mortality rate were comparable between the two periods. Over the 1-year-long period after the onset of the pandemic, our department provided care to 50 ESKD patients (32 males and 18 females) with COVID-19 infection who had a mean age of 66.3 ± 16.1 years. Of these, 33 patients (66%) were given discharge from the hospital, and the remaining 17 patients (34%) died.

CONCLUSION

This single-centre observational study shows a significant reduction in non-COVID-19 hospitalizations of ESKD patients in a tertiary University Hospital of Thessaloniki after the onset of the pandemic. However, the demographic characteristics of patients who were hospitalized, the duration of in-hospital care and clinical outcomes were comparable between the pandemic and control periods.

MO705: Factors Associated with Uncontrolled Ambulatory Hypertension in Peritoneal Dialysis Patients

BACKGROUND AND AIMS

Hypertension among patients on long-term peritoneal dialysis (PD) is common and remains often inadequately control (Cocchi et al. Prevalence of hypertension in patients on peritoneal dialysis: results of an Italian multicentre study. Nephrol Dial Transplant. 1999; 14(6): 1536–40; Vaios et al.. Assessment and management of hypertension among patients on peritoneal dialysis. Clin J Am Soc Nephrol. 2019; 14(2): 297–305). The aim of the present study was to describe the epidemiology of hypertension using the ‘gold-standard’ method of ambulatory blood pressure monitoring (ABPM) and to identify determinants of inadequate ambulatory blood pressure (BP) control in this high-risk population.

METHOD

In 140 stable patients receiving PD in four centers of Northern Greece, we performed 24-h ABPM using the oscillometric Mobil-O-Graph device (IEM, Stolberg Germany) (Franssen and Imholz. Evaluation of the Mobil-O-Graph new generation ABPM device using the ESH criteria. Blood Press Monit. 2010; 15(4): 229–31). Hypertension was defined as 24-h ambulatory BP ≥ 130/80 mmHg or current use of at least 1 BP-lowering medication (Williams et al. 2018 ESC/ESH guidelines for the management of arterial hypertension: the Task Force for the Management of Arterial Hypertension of the European Society of Cardiology and the European Society of Hypertension. J Hypertens. 2018; 36(10): 1953–2041). The volume status of study participants was assessed with the method of bioimpedance spectroscopy (Fresenius Medical Care, Bad Homburg, Germany). Univariate and multivariate binary logistic regression analysis was performed to identify factors that were independently associated with uncontrolled ambulatory hypertension.

RESULTS

Ambulatory hypertension was diagnosed in 95% of the patients enrolled in the study. Despite the fact that 96.9% of hypertensives were being treated with an average of 2.4 BP-lowering medications daily, adequate control of 24-h ambulatory BP was achieved in only 38.3% of them. In univariate regression analysis, there was a significant interaction of uncontrolled ambulatory hypertension with the mode of PD, history of cardiovascular disease and smoking status. In multivariate analysis, among variables inserted in the model, the higher overhydration index in bioimpedance spectroscopy [odds ratio (OR): 1.308; 95% confidence interval (CI): 1.023–1.673/L higher overhydration] and the history of cardiovascular disease (OR: 3.069; 95% CI: 1.157–8.140) were the two factors that were associated with higher odds of uncontrolled ambulatory hypertension. In contrast, the presence of residual diuresis ≥ 0.5 L/24 h (OR: 0.304; 95% CI: 0.105–0.881) was the only parameter associated with lower odds of inadequate ambulatory BP control.

CONCLUSION

Among patients on PD, ambulatory hypertension is highly prevalent and remains often poorly controlled, despite the extensive use of antihypertensive drug therapy. Achievement of adequate volume control and long-term preservation of residual kidney function appear to be two attractive non-pharmacological strategies for optimization of the management of hypertension in this high-risk population.

MO741: Poor Agreement between Physical Examination and Bioimpedance Spectroscopy in the Detection of Hypervolemia in Haemodialysis Patients

BACKGROUND AND AIMS

Assessment of dry-weight among patients on haemodialysis is challenging in the absence of reliable markers to define overhydration (OH) [1, 2]. This study aimed to explore the value of two simple clinical signs, the presence of pedal oedema and crackles at pulmonary auscultation, in diagnosing hypervolemia, using the bioimpendence spectroscopy as a more objective method.

METHOD

In a cohort of 107 asymptomatic dialysis patients, the volume status was assessed with physical examination and bioimpedance spectroscopy shortly before the mid-week dialysis session [3]. Patients were also asked to perform home blood pressure (BP) monitoring with a validated, automatic device (HEM-705, Omron, Healthcare) [4] for 1 week in order to determine their BP control status.

RESULTS

Patients within the high tertile of pre-dialysis OH had longer dialysis vintage, lower serum albumin and higher home systolic BP, despite the more aggressive treatment with a higher average number of antihypertensives daily. In receiver-operating-characteristic (ROC) curve analysis, pedal oedema [area under curve (AUC): 0.534, 95% confidence interval (95% CI) 0.416–0.651] and pulmonary crackles (AUC: 0.551; 95% CI 0.432–0.671) had limited accuracy in the diagnosis of pre-dialysis OH &gt; 2.2 L. The agreement of pedal oedema (Cohen's k-coefficient: 0.065) and pulmonary crackles (Cohen's k-coefficient: 0.122) with bioimpedance spectroscopy in the detection of hypervolemia was poor. In multivariate linear regression analysis, longer dialysis vintage (β: 0.306; P&lt;0.001) and higher home systolic BP (β: 0.287; P&lt;0.01) were the two factors that were independently associated with pre-dialysis OH.

CONCLUSION

This diagnostic-test study showed that among asymptomatic hemodialysis patients, pedal oedema and pulmonary crackles in physical examination had limited discriminatory power in the detection of hypevolemia, as assessed more objectively with the method of bioimpedance spectroscopy.

Vitamin K Supplementation for Prevention of Vascular Calcification in Chronic Kidney Disease Patients: Are We There Yet?

Chronic Kidney Disease (CKD) patients are at high risk of presenting with arterial calcification or stiffness, which confers increased cardiovascular mortality and morbidity. In recent years, it has become evident that VC is an active process regulated by various molecules that may act as inhibitors of vessel mineralization. Matrix Gla Protein (MGP), one the most powerful naturally occurring inhibitors of arterial calcification, requires vitamin K as a co-factor in order to undergo post-translational γ-carboxylation and phosphrorylation and become biologically active. The inactive form of MGP (dephosphorylated, uncarboxylated dp-ucMGP) reflects vitamin K deficiency and has been repeatedly associated with surrogate markers of VC, stiffness, and cardiovascular outcomes in CKD populations. As CKD is a state of progressive vitamin K depletion and VC, research has focused on clinical trials aiming to investigate the possible beneficial effects of vitamin K in CKD and dialysis patients. In this study, we aim to review the current evidence regarding vitamin K supplementation in uremic patients.

Prevalence, recurrence and seasonal variation of hyperkalemia among patients on hemodialysis

PURPOSE

Observational studies have shown that among patients on hemodialysis, hyperkalemia is strongly associated with excess risk for cardiovascular-related hospitalizations and sudden cardiac death. However, the actual burden of hyperkalemia, the rates of its recurrence and seasonality in its variation still remain unclear.

METHODS

Between June 2020 and May 2021, 1786 mid-week pre-dialysis serum potassium (sK) measurements were retrospectively recorded from 149 patients receiving thrice-weekly hemodialysis in a single-center in Thessaloniki, Greece. The prevalence, recurrence and seasonal variation of hyperkalemia were assessed using three pre-specified sK thresholds (≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L).

RESULTS

At baseline, 60.4%, 42.2% and 13.4% of patients had sK levels ≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L, respectively. At any time-point during follow-up, 85.2%, 69.8% and 38.9% of patients experienced at least one hyperkalemic event ≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L, respectively. Of the 104 patients experiencing an initial sK elevation ≥ 5.5 mmol/L, hyperkalemia at the same threshold reoccurred in 60.6% at month 1, in 47.1% at month 2 and in 46.1% at month 3 of follow-up. Seasonal variation was also observed, with the prevalence of hyperkalemia to be significantly higher in summer. Shorter delivered hemodialysis < 4 h/session (OR: 2.568; 95% CI 1.045-6.313) and the use of a high dialysate K concentration (OR: 14.646; 95% CI 2.727-78.647) were the 2 factors that were independently associated with hyperkalemia.

CONCLUSION

The present study shows that among hemodialysis patients, the rates of hyperkalemia prevalence and recurrence are very high, reflecting the large unmet need to identify more effective potassium-lowering therapeutic interventions in this high-risk population.

Epidemiology of Hypertension among Patients on Peritoneal Dialysis Using Standardized Office and Ambulatory Blood Pressure Recordings

INTRODUCTION

Prior studies conducted in peritoneal dialysis (PD) patients in the late 1990s provided considerably variable estimates of the prevalence and control of hypertension. The present study aimed to investigate the current state of hypertension management in this high-risk population.

METHODS

In 140 stable PD patients, we performed standardized automated office blood pressure (BP) measurements and 24-h ambulatory BP monitoring (ABPM) using the Mobil-O-Graph device (IEM, Germany). Office and ambulatory hypertension was diagnosed in patients with office BP ≥140/90 mm Hg and 24-h BP ≥130/80 mm Hg, respectively. Patients treated with ≥1 BP-lowering medications were also classified as hypertensives.

RESULTS

The prevalence of office and ambulatory hypertension was 92.9% and 95%, respectively. In all, 92.1% of patients were being treated with an average of 2.4 BP-lowering medications daily. Adequate BP control was achieved in 52.3% and 38.3% of hypertensives by office BP and ABPM, respectively. The agreement between these 2 techniques in the identification of patients with BP levels above the diagnostic thresholds of hypertension was moderate (k-statistic: 0.524). In all, 5% of patients were normotensives with both techniques, 31.4% had controlled hypertension, 5% had white-coat hypertension, 19.3% had masked hypertension, and 39.3% had sustained hypertension. Isolated nocturnal hypertension was detected in 23.6% of patients, whereas no patient had isolated daytime hypertension.

CONCLUSION

Among PD patients, hypertension is highly prevalent and remains often inadequately controlled. The use of ABPM enables the better classification of severity of hypertension and identification of isolated nocturnal hypertension, which is a common BP phenotype in the PD population.

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.

Mechanisms for Cardiorenal Protection of SGLT-2 Inhibitors

Despite optimal treatment of diabetic kidney disease (DKD) with adequate blood pressure control and agents blocking the renin-angiotensin-system (RAS), the residual cardiorenal risk of these patients remains substantially high. There is, therefore, an unmet need for additional therapies effective to retard the progression of DKD and improve cardiovascular outcomes in this high-risk population. Sodium-glucose co-transporter 2 (SGLT-2) inhibitors represent a novel drug class that received regulatory approval for improving glycemic control in patients with type 2 diabetes and preserved kidney function. Large outcome trials designed to test their cardiovascular safety profile showed an unexpected improvement in cardiovascular outcomes and also suggested a slower progression of DKD with SGLT-2 inhibition. The Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy (CREDENCE), a trial that was designed to specifically investigate the renoprotective properties of SGLT-2 inhibitors in patients with overt DKD already receiving guideline-based therapy with a RAS-blocker, was prematurely terminated due to an impressive benefit of canagliflozin on kidney and cardiovascular outcomes. These impressive results refine the role and the indication of SGLT-2 inhibitors as a cardioand renoprotective strategy in patients with DKD. In this article, we provide an overview of the available clinical- trial evidence and explore the mechanisms mediating the cardiorenal protection afforded by SGLT-2 inhibitors. We conclude with perspectives for a potential beneficial effect of this novel drug class in patients with non-diabetic kidney disease.

The Relation of Clinic and Ambulatory BP with the Risk of Cardiovascular Events and All-Cause Mortality among Patients on Peritoneal Dialysis

Large observational studies showed a U-shaped association of clinic blood pressure (BP) with mortality among patients undergoing peritoneal dialysis (PD). Whether ambulatory BP provides a more direct risk signal in this population remains unknown. In a prospective cohort of 108 PD patients, standardized clinic BP was recorded at baseline with the validated device HEM-705 (Omron, Healthcare, Bannockburn, IL, USA) and 24-h ambulatory BP monitoring was performed using the Mobil-O-Graph monitor (IEM, Stolberg, Germany). Over a median follow-up of 16 months (interquartile range: 19 months), 47.2% of the overall population reached the composite outcome of non-fatal myocardial infarction, non-fatal stroke, or all-cause death. In Cox-regression analysis, systolic but not diastolic BP was prognostically informative. Compared with the reference quartile 1 of 24-h systolic BP (SBP), the multivariate-adjusted hazard ratio for the composite outcome was 1.098 (95% confidence interval (CI): 0.434–2.777) in quartile 2, 1.004 (95% CI: 0.382–2.235) in quartile 3 and 2.449 (95% CI: 1.156–5.190) in quartile 4. In contrast, no such association was observed between increasing quartiles of clinic SBP and composite outcome. The present study shows that among PD patients, increasing ambulatory SBP is independently associated with higher risk of adverse cardiovascular events and mortality, providing superior prognostic information than standardized clinic SBP.

Physical examination for the detection of hypervolemia among patients on chronic dialysis: A diagnostic-test study

INTRODUCTION

Assessment of dry-weight among patients on dialysis is challenging in the absence of reliable markers to define fluid overload (FO). This study aimed to explore the value of two simple clinical signs, pedal edema, and crackles at pulmonary auscultation, in diagnosing hypervolemia, using bioimpendence spectroscopy (BIS) as reference standard.

METHODS

In a cohort of 107 asymptomatic dialysis patients, FO was assessed with physical examination and BIS shortly before the mid-week dialysis session. Patients were also asked to perform home blood pressure (BP) monitoring with a validated, automatic device (HEM-705, Omron, Healthcare) for 1 week in order to determine their BP outside of dialysis.

FINDINGS

Patients within the high tertile of predialysis FO had longer dialysis vintage, lower serum albumin and higher home systolic BP, despite the more aggressive treatment with a higher average number of antihypertensives daily. In receiver-operating-characteristic (ROC) curve analysis, pedal edema (area under curve [AUC]: 0.534; 95% confidence interval [CI]: 0.416-0.651) and pulmonary crackles (AUC: 0.551; 95% CI: 0.432-0.671) had limited accuracy in detecting excess predialysis FO > 2.2 L. The agreement of pedal edema (k-coefficient: 0.065) and pulmonary crackles (k-coefficient: 0.122) with BIS-derived FO was poor. In multivariate linear regression analysis, longer dialysis vintage (β: 0.306, p < 0.001) and higher home systolic BP (β: 0.287, p < 0.01) were the two factors that were associated with predialysis FO.

CONCLUSIONS

This study showed that among asymptomatic dialysis patients, pedal edema and pulmonary crackles in physical examination had limited discriminatory power in detection of FO, as assessed with the method of BIS.

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.

Prevalence and control of hypertension among patients on haemodialysis

BACKGROUND

Earlier studies provided considerably variable estimates on the prevalence and control rates of hypertension in haemodialysis because of their heterogeneity in definitions and blood pressure (BP) measurement techniques applied to detect hypertension.

MATERIALS AND METHODS

In this cross-sectional study, 116 clinically stable haemodialysis patients from 3 dialysis centres of Northern Greece underwent home BP monitoring for 1 week with the validated automatic device HEM-705 (Omron, Healthcare). Routine BP recordings taken before and after dialysis over 6 consecutive sessions were also prospectively collected and averaged. Hypertension was defined as: (a) 1-week averaged home BP ≥ 135/85 mm Hg; (b) 2-week averaged predialysis BP ≥ 140/90 mm Hg; and (c) 2-week averaged postdialysis BP ≥ 130/80 mm Hg. Participants on treatment with ≥1 antihypertensives were also classified as hypertensives.

RESULTS

The prevalence of hypertension was 88.8% by home, 86.2% by predialysis and 91.4% by postdialysis BP recordings. In all, 96 participants (82.7%) were being treated with an average of 2.0 ± 1.1 antihypertensive medications. Among drug-treated participants, 32.6% were controlled by home, 50.5% by predialysis and 45.3% by postdialysis BP recordings. In multivariate logistic regression analysis, greater use of antihypertensive medications and postdialysis overhydration, assessed with bioimpedance spectroscopy, were both independently associated with higher odds of inadequate home BP control.

CONCLUSIONS

This study shows that the prevalence, but mainly the control rates of hypertension in patients on haemodialysis, differs between peridialytic and interdialytic BP recordings. Therefore, the wider use of home BP monitoring may improve the determination of BP control status in this high-risk population.

P1189OFFICE AND AMBULATORY RECORDING OF CENTRAL AORTIC PRESSURES, WAVE REFLECTION AND ARTERIAL STIFFNESS INDICES IN PERITONEAL DIALYSIS PATIENTS

Background and Aims

Among peritoneal dialysis (PD) patients, aortic blood pressure (BP) and arterial stiffness indices are independent predictors of cardiovascular morbidity and mortality. Previous studies in PD patients recorded these parameters only in the office. The present study provides comparisons between office and ambulatory recordings of these parameters and explores the association of demographic, clinical and hemodynamic variables with high arterial stiffness.

Method

In 81 stable PD patients (mean age: 61.3±16.3 years; male gender: 64.2%), brachial and aortic BP, heart rate-adjusted augmentation index (AIx75) and pulse wave velocity (PWV) were recorded after a 5-minute seated rest in the office using the oscillometric device Mobil-O-Graph (IEM, Stolberg, Germany). Subsequently, all patients underwent ambulatory recording of these parameters with the same device for 24 hours. Logistic regression analysis was performed to identify factors independently associated with high ambulatory PWV.

Results

As expected, office brachial systolic BP (SBP) was higher than 24-hour brachial SBP (134.2±22.7 vs. 129.0±18.0 mmHg, P&lt;0.01). Similarly, office aortic SBP was higher than 24-hour aortic SBP (122.5±20.1 vs. 117.1±16.1 mmHg, P=0.001). By contrast, office AIx75 did not differ from 24-hour AIx75 (23.4%±11.7% vs. 23.9%±9.3%, P=0.602), whereas office PWV was only slightly higher than 24-hour PWV (9.2±2.3 vs. 9.0±2.2m/sec, P=0.001). Participants stratified in the high PWV tertile were older, had higher 24-hour mean BP (MBP) and had more commonly history of diabetes, dyslipidemia and coronary heart disease. In multivariate analysis, older age (OR: 4.23; 95% CI: 1.59-11.24) and higher 24-hour MBP (OR: 1.31; 95% CI: 1.03-1.67) were the only independent determinants of high PWV.

Conclusion

Among patients on PD, brachial and central aortic pressures recorded in the office were higher than 24-hour ambulatory pressures, whereas this variation between office and ambulatory recordings was diminished for AIx75 and PWV. Future studies are warranted to explore the prognostic significance of these parameters in the PD population.

P1459PREVALENCE AND CONTROL OF HYPERTENSION AMONG PATIENTS ON HEMODIALYSIS USING PREDIALYSIS, POSTDIALYSIS AND HOME BP RECORDINGS

Background and Aims

Earlier studies provided considerably variable estimates on the prevalence and control rates of hypertension in hemodialysis because of their heterogeneity in definitions and blood pressure (BP) measurement techniques applied to detect hypertension.

Method

In the present study, 116 clinically stable hemodialysis patients from 3 dialysis centers of Northern Greece underwent home BP monitoring for 1 week with the validated automatic device HEM-705 (Omron, Healthcare). Routine BP recordings taken before and after dialysis over 6 consecutive sessions were also prospectively collected and averaged. Hypertension was defined as: (i) 1-week averaged home BP ≥135/85 mmHg; (ii) 2-week averaged predialysis BP ≥140/90 mmHg; (iii) 2-week averaged postdialysis BP ≥130/80 mmHg. Participants on treatment with ≥1 antihypertensives were also classified as hypertensives.

Results

The prevalence of hypertension was 88.8% by home, 86.2% by predialysis and 91.4% by postdialysis BP recordings. In all, 96 participants (82.7%) were being treated with an average of 1.7 antihypertensive medications. Among drug-treated participants, 32.6% were controlled by home, 50.5% by predialysis and 45.3% by postdialysis BP recordings. In multivariate logistic regression analysis, greater use of antihypertensive medications and postdialysis overhydration, assessed with bioimpendence spectroscopy, were both independently associated with higher odds of inadequate home BP control.

Conclusion

This study shows that epidemiology of hypertension in hemodialysis differs considerably between routine dialysis-unit and home BP recordings. Since greater antihypertensive drug use and postdialysis overhydration appeared to be the major determinants of inadequate home BP control, then management of hypertension should be initially relied on strategies targeting to control volume overload.

P1216EPIDEMIOLOGY OF HYPERTENSION IN PERITONEAL DIALYSIS USING CLINIC AND AMBULATORY BLOOD PRESSURE MONITORING

Background and Aims

Earlier studies that were based on routine clinic blood pressure (BP) recordings suggested that the prevalence of hypertension is lower in patients on peritoneal dialysis (PD) than in those receiving maintenance hemodialysis. These studies, however, did not incorporate the “gold-standard” method of ambulatory BP monitoring (ABPM). The aim of the present study was to quantify the prevalence and control of hypertension in a cohort of 81 peritoneal dialysis (PD) patients using clinic and ambulatory BP recordings.

Method

Triplicate BP recordings were obtained after a 5-minute seated rest at clinic with the validated monitor HEM-705 CP (Omron, HealthCare). 24-hour ABPM was subsequently performed with the Mobil-O-Graph device (IEM, Germany). Hypertension was defined as (i) average clinic BP ≥140/90 mmHg or antihypertensive drug use and (ii) 24-hour BP ≥130/80 mmHg or current use of antihypertensive drugs.

Results

The prevalence of hypertension was 92.6% with clinic BP recordings and 93.8 with ABPM. In all, 75 participants (92.6%) were receiving therapy with an average of 2.4 antihypertensive medications. The rates of adequate control of hypertension were 49.3% with the use of clinic BP recordings and 39.5% with ABPM, respectively. In all, 6.2% of participants were classified as normotensives, 33.3% had concordant control of hypertension with both techniques, 40.7% had concordant lack of control confirmed by both techniques, 5% had “white coat” hypertension and 14.8% had masked uncontrolled hypertension.

Conclusion

This study suggests that the burden of hypertension among patients on PD is very high and that the wider use of ABPM is important to confirm the BP control status of these patients.

Clinic and Home Blood Pressure Monitoring for the Detection of Ambulatory Hypertension Among Patients on Peritoneal Dialysis

The International Society of Peritoneal Dialysis recommends that adequate blood pressure (BP) assessment among patients on peritoneal dialysis should at least include measurements performed once-weekly at home and at each visit at clinic. However, the quality of evidence to support this guidance is suboptimal. Using ambulatory daytime BP as reference standard, we explored the diagnostic performance of clinic and home BP recordings in a cohort of 81 stable patients receiving peritoneal dialysis. BP was recorded using 3 different methodologies: (1) triplicate automated clinic BP recordings after a 5-minute seated rest with the validated monitor HEM 705 CP (Omron Healthcare); (2) 1-week averaged home BP recorded with a validated automated monitor on awaking and at bedtime; and (3) ambulatory BP monitoring with the Mobil-O-Graph device (IEM, Germany). The area under the curve of receiver operating characteristic curves in detection of ambulatory daytime systolic BP (SBP) ≥135 mm Hg was similar for clinic [area under the curve, 0.859; 95% CI, 0.776-0.941] and home SBP (area under the curve, 0.895; 95% CI, 0.815-0.976). In Bland-Altman analysis, clinic SBP overestimated daytime ambulatory SBP by 5.02 mm Hg with 95% limits of agreement ranging from -17.92 to 27.96 mm Hg. Similarly, home SBP overestimated daytime ambulatory SBP by 4.23 mm Hg, again with wide 95% limits of agreement (-16.05 to 24.51 mm Hg). These results show that 1-week averaged home SBP is of at least similar accuracy with standardized clinic SBP in diagnosing hypertension confirmed by ambulatory BP monitoring among patients on peritoneal dialysis.

Assessment and Management of Hypertension among Patients on Peritoneal Dialysis

Approximately 7%-10% of patients with ESKD worldwide undergo peritoneal dialysis (PD) as kidney replacement therapy. The continuous nature of this dialytic modality and the absence of acute shifts in pressure and volume parameters is an important differentiation between PD and in-center hemodialysis. However, the burden of hypertension and prognostic association of BP with mortality follow comparable patterns in both modalities. Although management of hypertension uses similar therapeutic principles, long-term preservation of residual diuresis and longevity of peritoneal membrane function require particular attention in the prescription of the appropriate dialysis regimen among those on PD. Dietary sodium restriction, appropriate use of icodextrin, and limited exposure of peritoneal membrane to bioincompatible solutions, as well as adaptation of the PD regimen to the peritoneal transport characteristics, are first-line therapeutic strategies to achieve adequate volume control with a potential long-term benefit on technique survival. Antihypertensive drug therapy is a second-line therapeutic approach, used when BP remains unresponsive to the above volume management strategies. In this article, we review the available evidence on epidemiology, diagnosis, and treatment of hypertension among patients on PD and discuss similarities and differences between PD and in-center hemodialysis. We conclude with a call for randomized trials aiming to elucidate several areas of uncertainty in management of hypertension in the PD population.

Icodextrin-associated generalized exfoliative skin rash in a CAPD patient: a case-report

Background

Case presentation

Conclusions

Accuracy of a Newly-Introduced Oscillometric Device for the Estimation of Arterial Stiffness Indices in Patients on Peritoneal Dialysis: A Preliminary Validation Study

The aim of the present study was to compare the aortic systolic blood pressure (aSBP), heart-rate-adjusted augmentation index (AIx₇₅), and pulse wave velocity (PWV) obtained using the Mobil-O-Graph (IEM, Stolberg, Germany) and SphygmoCor (AtCor, Sydney, Australia) devices in patients receiving peritoneal dialysis (PD).After a 10-minute rest in the supine position, the Mobil-O-Graph and SphygmoCor devices were applied in randomized order in 27 consecutive PD patients. The agreement between the measurements produced by the Mobil-O-Graph and SphygmoCor devices was explored using Bland-Altman analysis.The Mobil-O-Graph-derived aSBP, AIx₇₅, and PWV did not differ from the same measurements obtained with SphygmoCor (aSBP: 120.5 ± 18.2 mmHg vs. 124.4 ± 19.0 mmHg, p = 0.438; AIx₇₅: 27.0% ± 12.4% vs. 24.5% ± 10.6%, p = 0.428; PWV: 9.5 ± 2.1 m/s vs. 10.1 ± 3.1 m/s, p = 0.397). The slight difference in the estimation of aSBP is possibly explained by the difference in brachial SBP used for the calibration of the devices (131.0 ± 20.6 mmHg vs. 134.5 ± 19.7 mmHg, p = 0.525). Mobil-O-Graph-derived measurements correlated strongly with paired measurements obtained with the SphygmoCor device. Bland-Altman plots showed no evidence of asymmetry and a wide range of agreement between the two devices.Our study shows acceptable agreement between Mobil-O-Graph and SphygmoCor in the estimation of arterial stiffness indices in PD patients. Accordingly, the Mobil-O-Graph device accurately performs aortic ambulatory blood pressure monitoring in this population.

Mineralocorticoid Antagonists in ESRD: An Overview of Clinical Trial Evidence

BACKGROUND

Add-on therapy with the Mineralocorticoid-Receptor-Antagonists (MRAs) spironolactone and eplerenone was shown to enhance the cardioprotective action of angiotensinconverting- enzyme-inhibitors (ACEIs), angiotensin-receptor-blockers (ARBs) and/or β-blockers in nondialysis patients with congestive heart failure (CHF) and reduced left ventricular (LV) ejection fraction. The risk/benefit ratio of MRAs in dialysis patients is less well defined, owing to concerns that their cardioprotective actions may be counteracted by excess risk of hyperkalemia.

METHODS

We performed a systematic literature search of MEDLINE/PubMed database (inception to September 15, 2016) to identify randomized controlled studies evaluating the effects of spironolactone and eplerenone on surrogate cardiovascular risk factors and clinical outcomes in patients receiving hemodialysis or peritoneal dialysis.

RESULTS

A growing body of evidence derived from small randomized studies suggests that MRA therapy improves a number of surrogate cardiovascular risk factors (i.e. blood pressure, LV mass index, LV ejection fraction, carotid intima-media-thickness) in long-term dialysis patients. Two larger studies evaluating "hard" cardiovascular endpoints showed that these cardioprotective actions of MRAs are translated into a clinically relevant (up to 60%) reduction in the risk of all-cause and cardiovascular mortality. On the other hand, MRA use was shown to be accompanied by a parallel increase in the risk of hyperkalemia and gynecomastia.

CONCLUSION

Small, hypothesis-generating randomized trials support a cardioprotective role of MRA therapy in patients receiving hemodialysis or peritoneal dialysis. These promising results call for larger, properly-designed studies aiming to fully elucidate the potential harms and benefits of MRAs in this high-risk population. In anticipation of the results of ongoing outcome trials, the wide use of MRAs in dialysis patients should be avoided.

Evaluation of the tolerability and efficacy of sodium polystyrene sulfonate for long-term management of hyperkalemia in patients with chronic kidney disease

PURPOSE

Sodium polystyrene sulfonate (SPS) is a cation-exchanging resin that has been widely used for several decades as first-line therapy of mild chronic hyperkalemia in patients with chronic kidney disease (CKD). However, evidence to prove the long-term tolerability and efficacy of SPS for the treatment of this condition is still missing.

METHODS

In this retrospective, observational study, we enrolled 26 outpatients with stages 3-4 CKD who received oral therapy with low-dose SPS for mild chronic hyperkalemia in the Outpatient Nephrology clinic of our Department during 2010-2016. We obtained medical records on side effects potentially attributable to SPS use, and we analyzed the changes in serum electrolytes before and after the initiation of SPS therapy.

RESULTS

Serum potassium levels fell from 5.9 ± 0.4 to 4.8 ± 0.5 mmol/l (P < 0.001) over a median follow-up of 15.4 months (range 3-27 months). SPS use was associated with a slight, but significant elevation in serum sodium levels (139.5 ± 2.9 vs 141.2 ± 2.4, P = 0.006), whereas serum calcium and phosphate remained unchanged before and after the initiation of SPS. We recorded ten episodes of recurrent serum potassium elevation ≥ 5.5 mmol/l, none of which required hospitalization or acute dialysis. No episode of colonic necrosis or any other serious drug-related adverse event was observed. SPS therapy was well-tolerated, since only 1 out of 26 patients discontinued SPS at 3 months due to gastrointestinal intolerance.

CONCLUSION

This study suggests that low-dose SPS is well-tolerated and can effectively normalize elevated serum potassium over several weeks in CKD outpatients with mild chronic hyperkalemia.

Bone Quality Assessment as Measured by Trabecular Bone Score in Patients With End-Stage Renal Disease on Dialysis

Patients with end-stage renal disease (ESRD) on maintenance hemodialysis (HD) exhibit osteoporosis and increased fracture risk. Dual-energy X-ray absorptiometry scan measurements and calculation of fracture risk assessment toll score underestimate fracture risk in these patients and do not estimate bone quality. Trabecular bone score (TBS) has been recently proposed as an indirect measure of bone microarchitecture. In this study, we investigated alterations of bone quality in patients with ESRD on HD, using TBS. Fifty patients with ESRD on HD, with a mean age 62 years, and 52 healthy individuals matched for age, body mass index, and gender, were enrolled. All participants had a bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry scan at the lumbar spine, femoral neck, total hip, and 1/3 radius. TBS was evaluated using TBS iNsight. Serum fetuin-A and plasma fibroblast growth factor-23 (FGF-23) (C-terminal) were also measured. Patients on dialysis had significantly lower BMD values at all skeletal sites measured. Plasma FGF-23 levels significantly increased and serum fetuin-Α significantly decreased in patients on dialysis compared with controls. TBS was significantly reduced in patients on dialysis compared with controls (1.11 ± 0.16 vs 1.30 ± 0.13, p < 0.001, respectively) independently of age; BMD; duration of dialysis; and serum levels of alkaline phosphatase, 25-OH-vitamin D, parathyroid hormone, fetuin-A, or plasma FGF-23. Patients on HD who were diagnosed with an osteoporotic vertebral fracture had numerically lower TBS values, albeit without reaching statistical significance, compared with patients on dialysis without a fracture (1.044 ± 0.151 vs 1.124 ± 0.173, respectively, p = 0.079). Bone microarchitecture, as assessed by TBS, is significantly altered in ESRD on patients on HD independently of BMD values and metabolic changes that reflect chronic kidney disease-mineral and bone disorder.

Improvements in the Management of Diabetic Nephropathy

The burden of diabetes mellitus is relentlessly increasing. Diabetic nephropathy is the most common cause of end-stage renal disease (ESRD) worldwide and a major cause of morbidity and mortality in patients with diabetes. The current standard therapy of diabetic nephropathy involves intensive treatment of hyperglycemia and strict blood pressure control, mainly via blockade of the renin-angiotensin system (RAS). Attention has been drawn to additional beneficial effects of oral hypoglycemic drugs and fibrates on other aspects of diabetic nephropathy. On the other hand, antiproteinuric effects of RAS combination therapy do not seem to enhance the prevention of renal disease progression, and it has been associated with an increased rate of serious adverse events. Novel agents, such as bardoxolone methyl, pentoxifylline, inhibitors of protein kinase C (PKC), sulodexide, pirfenidone, endothelin receptor antagonists, vitamin D supplements, and phosphate binders have been associated with controversial outcomes or significant side effects. Although new insights into the pathogenetic mechanisms have opened new horizons towards novel interventions, there is still a long way to go in the field of DN research. The aim of this review is to highlight the recent progress made in the field of diabetes management based on the existing evidence. The article also discusses novel targets of therapy, with a special focus on the major pathophysiologic mechanisms implicated in the initiation and progression of diabetic nephropathy.