Association of Pulmonary Hypertension with Mortality in Incident Peritoneal Dialysis Patients

Predictors, prevalence and prognostic role of pulmonary hypertension in patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

To estimate the predictors, prevalence and prognostic role of pulmonary hypertension (PH) in patients with chronic kidney disease (CKD) using meta-analysis.

METHODS

The PubMed, EmBase, and the Cochrane library were systematically searched for eligible studies from inception till May 2024. All of pooled analyses were performed using the random-effects model.

RESULTS

Fifty observational studies involving 17,558 CKD patients were selected. The prevalence of PH in CKD patients was 38% (95% confidence interval [CI]: 33%-43%), and the prevalence according to CKD status were 31% (95% CI: 20%-42%) for CKD (I-V), 39% (95% CI: 25%-54%) for end stage kidney disease (ESKD) (predialysis), 42% (95% CI: 35%-50%) for ESKD (hemodialysis), and 26% (95% CI: 19%-34%) for renal transplant. We noted the risk factors for PH in CKD included Black individuals (relative risk [RR]: 1.39; 95% CI: 1.18-1.63; p < 0.001), chronic obstructive pulmonary disease (RR: 1.48; 95% CI: 1.21-1.82; p < 0.001), cardiovascular disease history (RR: 1.62; 95% CI: 1.05-2.51; p = 0.030), longer dialysis (RR: 1.70; 95% CI: 1.18-2.46; p = 0.005), diastolic dysfunction (RR: 1.88; 95% CI: 1.38-2.55; p < 0.001), systolic dysfunction (RR: 3.75; 95% CI: 2.88-4.87; p < 0.001), and grade 5 CKD (RR: 5.64; 95% CI: 3.18-9.98; p < 0.001). Moreover, PH in CKD patients is also associated with poor prognosis, including all-cause mortality, major cardiovascular events, and cardiac death.

CONCLUSION

This study systematically identified risk factors for PH in CKD patients, and PH were associated with poor prognosis. Therefore, patients with high prevalence of PH should be identified for treatment.

Prevalence, Predictors, and Outcomes of Pulmonary Hypertension in Patients with Lupus Nephritis

Background and Objectives: This study aimed to assess the prevalence, predictors, and outcomes of pulmonary hypertension (PH) in patients with lupus nephritis (LN). Materials and Methods: Baseline characteristics and clinical outcomes of 387 patients with LN were retrospectively collected from 2007 to 2017. PH was defined as pulmonary artery systolic pressure ≥40 mmHg assessed by resting transthoracic echocardiography. The primary endpoint was all-cause mortality. The secondary endpoint was renal events, defined as the doubling of baseline serum creatinine or end-stage renal disease. Associations between PH and outcomes were analyzed by Cox regression models. Results: A total of 15.3% (59/387) of patients with LN were diagnosed with PH, and the prevalence of PH was higher for patients with an estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 compared to those with an eGFR ≥ 30 mL/min/1.73 m2 (31.5% vs. 12.6%). Higher mean arterial pressure, lower hemoglobin, and lower triglyceride levels were associated with greater odds of having PH. After adjusting for relevant confounding variables, PH was independently associated with a higher risk for death (HR: 2.01; 95% CI: 1.01-4.00; p = 0.047) and renal events (HR: 2.07; 95% CI: 1.04-4.12; p = 0.039). Conclusions: PH is an independent risk factor for all-cause mortality and adverse renal outcomes in patients with LN.

Impact of pulmonary hypertension on arteriovenous fistula failure of hemodialysis patients: A 10 years follow-up cohort study

BACKGROUND

Pulmonary hypertension (PH) is common in patients with end-stage renal disease (ESRD). Arteriovenous fistulas (AVF) creation may involve in the pathogenesis of PH. The aim of this study was to explore the impact of PH after AVF creation on the AVF failure rate in maintenance hemodialysis (MHD) patients.

METHODS

From January 1, 2009, to January 1, 2019, we retrospectively collected data of 578 MHD patients in Guangdong Provincial People's Hospital Blood Purification Center, China. Patients were followed-up until AVF failure or death or May 25, 2020. According to the systolic pulmonary artery pressure (SPAP) within 1 year after the establishment of AVF, the MHD patients were divided into three groups: SPAP ⩽ 35 mmHg, 35 < SPAP < 45 mmHg, SPAP ⩾ 45 mmHg. The primary outcome was AVF failure defined as AVF cannot complete hemodialysis. The secondary outcomes were all-cause mortality.

RESULTS

A total of 578 patients were analyzed. The average age was 60.66 ± 15.34 years (58.1% men). Of these, 26.1% of patients were reported PH. The SPAP exhibited a left-skewed nonparametric distribution and the overall SPAP after the creation of AVF was 39.00 (29.00-52.00) mmHg. The median follow-up was 5.8 (5.5-6.3) years. Overall, 12.8% (74/578) patients were reported AVF failure events. There was no significant difference in AVF failure rate among three groups (p = 0.070). A total of 111 (19.2%) died during the follow-up period. Compared with the SPAP ⩽35 mmHg group, only the all-cause death rate significantly increased in MHD patients with PH (p < 0.001).

CONCLUSIONS

The secondary pulmonary hypertension after AVF creation did not increase the risk of AVF failure in MHD patients, but significantly increased the risk of mortality for this portion of the patients. Future larger sample sizes, multi-center, and prospective trials are needed to make sure which type of access will benefit on their survival for MHD patients with SPAP ⩾35 mmHg.

The significance of volume overload in the development of pulmonary arterial hypertension in continuous ambulatory peritoneal dialysis patients

INTRODUCTION

The underlying pathophysiology of pulmonary arterial hypertension (PAH) is multifactorial; however, the significance of chronic volume overload and its subsequent effects on cardiac function must be studied thoroughly. The main objective of this study was to determine the predictive parameters of PAH in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) using transthoracic echocardiography (TTE) and bioimpedance analysis (BIA).

METHODS

In this cross-sectional study, 43 eligible CAPD patients were chosen. The patients were examined by TTE and BIA before the morning dialysis session, and baseline patient characteristics, echocardiography, and BIA parameters were recorded.

RESULTS

Sixteen (37.2%) patients were diagnosed with PAH. Patients with PAH had significantly greater left atrial diameter (LAD), left ventricular mass index (LVMI), and higher grades of diastolic dysfunction (DDF). Systolic pulmonary artery pressure (sPAP) correlated with LAD (p < 0.001, r = 0.566), interventricular septal diameter (IVSD) (p = 0.004, r = 0.425), LVMI (p = 0.030, r = 0.323), and extracellular water/total body water (ECW/TBW) ratio (p = 0.002, r = 0.458).

CONCLUSION

Two volume status-related parameters including ECW/TBW ratio and inferior vena cava (IVC) expiratory diameter, and cardiac-related TTE findings such as LAD and DDF were predictors of sPAP in CAPD patients.

The problem of pulmonary arterial hypertension in end-stage renal disease: can peritoneal dialysis be the solution

BACKGROUND

Pulmonary arterial hypertension (PAH) in the setting of end-stage renal disease (ESRD) has important prognostic and therapeutic consequences. We estimated the prevalence of PAH among patients with ESRD treated with automated peritoneal dialysis (APD), investigated the effect of different variables and compared pulmonary artery pressure and cardiac function at the beginning and end of the study.

METHODS

This is a 5-year study in which 31 ESRD patients on APD were recruited after fulfilling inclusion criteria. Blood samples were collected from all patients for the biochemical and hematological data at the beginning of the study and every month and at the study termination. Total body water (TBW) and extracellular water (ECW) were calculated using Watson's and Bird's calculation methods. All patients were followed-up at 3-month interval for cardiac evaluation. Logistic regression analysis was used to assess the relation between different variables and PAH.

RESULTS

The mean age of the study population (n = 31) was 51.23 ± 15.24 years. PAH was found in 24.2% of the patients. Mean systolic pulmonary artery pressure (sPAP) and mean pulmonary artery pressure (mPAP) were significantly higher in the APD patients at study initiation than at the end of the study (40.75 + 10.61 vs 23.55 + 9.20 and 29.66 + 11.35 vs 18.24 + 6.75 mmHg respectively, p = 0.001). The median ejection fraction was significantly lower in patients with PAH at zero point than at study termination [31% (27-34) vs 50% (46-52), p = 0.002]. Hypervolemia decreased significantly at the end of study (p <  0.001) and correlated positively with the PAP (r = 0.371 and r = 0.369), p = 0.002). sPAP correlated with left ventricular mass index, hemoglobin level, and duration on APD.

CONCLUSIONS

Long term APD (> 1 years) seemed to decrease pulmonary arterial pressure, right atrial pressure and improve left ventricular ejection fraction (LVEF). Risk factors for PAH in ESRD were hypervolemia, abnormal ECHO findings and low hemoglobin levels. Clinical and echocardiographic abnormalities and complications are not uncommon among ESRD patients with PAH. Identification of those patients on transthoracic echocardiography may warrant further attention to treatment with APD.

Effect of Mean Platelet Volume to Platelet Count Ratio on Mortality in Peritoneal Dialysis

Background and Aims

Mean platelet volume to platelet count ratio (MPV/PC) has been found to be an independent risk factor for mortality in various diseases, including cardiovascular disease, cancer, and hemodialysis. We aimed to evaluate the association between MPV/PC and all-cause and cardiovascular (CV) mortality in peritoneal dialysis (PD) patients.

Methods and Results

We conducted a retrospective cohort study at a single center and enrolled 1473 PD patients who were catheterized at our PD center from January 1, 2006, to December 31, 2013. All patients were divided into four groups according to the quartiles of baseline MPV/PC levels and followed up until December 31, 2018. A total of 453 patients died, and 221 deaths were caused by cardiovascular disease during a median follow-up time of 48.0 (21.9-82.2) months. There was a significant interaction by age of association between MPV/PC level and all-cause mortality (P = 0.009), and multivariate Cox regression analysis showed that higher MPV/PC level was related to a decreased risk of all-cause and CV mortality in PD patients aged < 60 years (HR = 0.62, 95%CI = 0.40 − 0.96, P = 0.032; HR = 0.49, 95%CI = 0.26 − 0.93, P = 0.029, respectively), rather than in patients aged ≥ 60 years (HR = 1.37, 95%CI = 0.84 − 2.22, P = 0.208; HR = 1.50, 95%CI = 0.77 − 2.92, P = 0.237, respectively).

Conclusion

Our results indicated that low MPV/PC level was an independent risk factor for all-cause and CV mortality in PD patients aged less than 60 years.

The potential effect of cardiac function on pulmonary hypertension, other risk factors, and its impact on survival in dialysis patients

INTRODUCTION

Pulmonary hypertension (PH) is a recently recognized as a complication of chronic kidney disease and end-stage renal disease. The pathogenesis of pulmonary hypertension in this group of patients is not fully understood, probably due to the interaction of multiple aspects of the altered cardiovascular physiology and also hormonal and metabolic disorders. The present study aimed to determine the prevalence of PH, correlation with cardiac function and other risk factors and its impact of survival in chronic hemodialysis and peritoneal dialysis patients.

METHODS

We studied 125 stable hemodialysis and peritoneal patients (females 40%, mean age 52.42 ± 11.88 years) on renal replacement therapy (RRT) for more than 3 months with a follow up 2 years. Demographic information, clinical characteristics, blood test, and thoroughly echocardiographic evaluation at the optimal dry weight were collected. After conventional echocardiographic examination, tissue Doppler echocardiographic (TDE) examination was performed to evaluate global and regional myocardial systolic as well as diastolic function, and pulmonary hypertension. PH was defined as systolic pulmonary artery pressure (sPAP) ≥ 35 mmHg. To rule out secondary PH, patients with pulmonary disease, collagen vascular disease, and volume overload at the time of echocardiography were excluded. Variables were compared between two groups-subjects with PH and non-PH. Logistic regression analysis was used to evaluate the risk factor for PH and its impact on survival.

RESULTS

According to the echocardiographic findings, PH was found in 28% (35 patients) of all patients. Mean PH was 33.46 ± 5.38 mmHg. The higher level of higher parathormone (PTH), C-reactive protein (CRP) and E/E' average, lower left ventricular ejection fraction (EF), peak systolic velocity at the lateral mitral annulus (MASa) and the peak systolic velocity at the lateral tricuspid annulus (TASa) were found predictor of PH. The cardiovascular mortality rate was 15.5%. Patients evaluated with PH have a significantly lower cardiovascular survival rate [Long Rank (Mantel-Cox) p = 0.0001]. In ROC analysis for CV mortality, the area under the curve (AUC) for PH and CRP was found 0.8; for LVM-I, E/E' and PP, AUC = 0.76; 0.75; 0.72 respectively while the inverse relationship was found with MASa and TASa with AUC = 0.66 and 0.95 respectively.

CONCLUSION

Our study shows that PH is frequent in dialysis patients. It is influenced by inflammation, CKD-MBD biomarkers associated with diastolic and also systolic left and right ventricle dysfunction. Pulmonary hypertension, inflammation, vascular stiffness, and left ventricular hypertrophy are interrelated and all contribute to cardiovascular morbidity and mortality among dialysis patients. Easy to implement, cardiac imaging at the bedside and in outpatient clinics offers a positive perspective in early diagnosis of cardiac abnormalities and immediate approach to this condition, so is highly recommended in the dialysis population.

Serum Sodium Modifies the Association of Systolic Blood Pressure with Mortality in Peritoneal Dialysis Patients

INTRODUCTION

High serum sodium is associated with increased blood pressure (BP) in dialysis patients, which is a risk factor for cardiovascular (CV) disease. However, the interaction between serum sodium and BP and their association with clinical outcomes in peritoneal dialysis (PD) patients is uncertain.

METHODS

We analyzed a retrospective cohort of 1,656 incident PD patients from January 2006 to December 2013, who were followed up until December 2018. Cox proportional hazards regression models were used to evaluate the association of serum sodium and BP with all-cause and CV mortality. A priori interaction between serum sodium and systolic BP (SBP) was explored, and a subgroup analysis was performed by stratifying SBP into the following 3 groups: <110, 110-130, and >130 mm Hg.

RESULTS

Mean baseline serum sodium was 140.2 ± 3.6 mmol/L, mean SBP was 137 ± 20 mm Hg, and diastolic BP was 85 ± 14 mm Hg. During a median (range) follow-up time of 46.5 (2.6-154.3) months, 507 patients died, 252 of whom died due to CV disease. SBP did not predict all-cause and CV mortality when BP was assessed as a continuous variable. However, SBP >130 or <110 mm Hg was associated with higher risk of all-cause and CV mortality compared with SBP of 110-130 mm Hg. There was a significant interaction between baseline serum sodium and SBP for all-cause mortality (p for interaction = 0.016). In subgroup analysis, among those with SBP >130 mm Hg, the risk of all-cause mortality was elevated in those with serum sodium ≥140 mmol/L (adjusted hazard ratio [aHR] 1.45 [95% confidence interval (CI): 1.07-1.98]), but not for those with serum sodium <140 mmol/L (aHR 1.27 [95% CI: 0.89-1.82]). Conversely, among those with SBP <110 mm Hg, those with serum sodium <140 mmol/L had an elevated risk of mortality (aHR 1.99 [95% CI: 1.31-3.02]), but not those with serum sodium ≥140 mmol/L (aHR 1.15 [95% CI: 0.74-1.79]) (p for interaction = 0.028).

CONCLUSION

The association of BP with mortality was modified by serum sodium levels in PD patients. Further studies are needed to evaluate whether individualized BP control based on serum sodium levels contributes to improve patient outcomes.

Prognostic value of pulmonary hypertension in pre-dialysis chronic kidney disease patients

BACKGROUND

Pulmonary hypertension is common in chronic kidney disease (CKD) patients. However, the prognostic value of pulmonary hypertension in Chinese predialytic CKD patients is rarely reported. We evaluated the relevant factors and prognostic value of pulmonary hypertension in CKD patients.

METHODS

This retrospective cohort study enrolled 1092 predialytic patients from The Third Affiliated Hospital of Sun Yat-Sen University from May 1st, 2011, to December 31st, 2016. Data of interest were retrieved from electronic medical records. Pulmonary hypertension was defined as pulmonary arterial systolic pressure (PASP) ≥ 35 mmHg by echocardiology. All participants were followed from the date of the first echocardiography examination. The primary endpoints were all-cause mortality and cardiovascular mortality. The secondary endpoint was end-stage renal disease (ESRD) defined as starting renal replacement therapy.

RESULTS

The prevalence of pulmonary hypertension was 15.9% in the study population. For CKD stage 1, 2, 3a, 3b, 4 and 5, the prevalence was 6.0%, 9.6%, 17.2%, 13.3%, 20.7% and 26.6%, respectively. Older age, lower left ventricular ejection fraction, anemia and higher pulse pressure were independently associated with pulmonary hypertension in CKD patients. In multivariate Cox regression analysis, pulmonary hypertension was the independent risk factor for cardiovascular mortality, but not of all-cause mortality and ESRD.

CONCLUSIONS

Pulmonary hypertension is not rare in early CKD patients. Patients with older age, anemia, higher pulse pressure and compromised heart function were more likely to comorbid pulmonary hypertension. Pulmonary hypertension maybe a sign of worse cardiovascular outcome in CKD patients.

Diagnosis and Management of Pulmonary Hypertension in Patients With CKD

Pulmonary hypertension (PH) is a highly prevalent and important condition in adults with chronic kidney disease (CKD). In this review, we summarize the definition of PH, discuss its pathophysiology and classifications, and describe diagnostic and management strategies in patients with CKD, including those with kidney failure treated by kidney replacement therapy. In the general population, PH is classified into 5 groups based on clinical presentation, pathology, hemodynamics, and management strategies. In this classification system, PH in CKD is placed in a diverse group with unclear or multifactorial mechanisms, although underlying cardiovascular disease may account for most cases. CKD may itself directly incite pulmonary circulatory dysfunction and remodeling through uremic toxins, inflammation, endothelial dysfunction, and altered vasoregulation. Despite several studies describing the higher prevalence of PH in CKD and kidney failure, along with an association with poor outcomes, high-quality evidence is not available for its diagnostic and management strategies in those with CKD. In CKD not requiring kidney replacement therapy, volume management along with treatment of underlying risk factors for PH are critical. In those receiving hemodialysis, options are limited and transition to peritoneal dialysis may be considered if recurrent hypotension precludes optimal volume control.

Relationship between volume status and possibility of pulmonary hypertension in dialysis naive CKD5 patients

Background

Chronic fluid overload is common in patients with chronic kidney disease (CKD) and can with time lead to poor prognosis regarding to the cardiovascular events. Serum NT-proBNP and OH/ECW might reflect fluid status of the patients, and the maximal tricuspid regurgitation velocity (TRVmax) could reflect systolic pulmonary artery pressure (SPAP). We investigated the relationship between markers of volume status and marker of pulmonary hypertension (PH) in non-dialysis CKD5 (CKD5-ND) patients.

Methods

Bioimpedance spectroscopy (BIS), echocardiography, and measurement of serum NT-proBNP were performed in 137 consecutive patients on the same day. TRVmax greater than or equal to 2.9 m/s, corresponding to SPAP of approximately 36 mmHg, was used as a definition of the possibility of PH in the absence of left heart disease and chronic respiratory disease (PH group).

Results

Patients with possibility of PH (TRVmax ≥ 2.9 m/s) was found in 27 (19.70%) patients. Among the values obtained from BIS, those reflecting the fluid balance (OH, OH/ECW, and E/I ratio) were significantly higher in the PH group. The OH/ECW in patients with PH were significantly higher than those patients without (26.76 ± 15.07 vs. 13.09 ± 15.05, P < 0.001). NT-proBNP was also significantly higher in PH group compared to the non-PH group (median = 10,112 pg/ml, IQR = 30,847 pg/ml vs. median = 1,973 pg/ml, IQR = 7,093 pg/ml, P < 0.001). OH/ECW was positively associated with TRVmax (r = 0.235, P = 0.006). Multivariate logistic regression revealed that increased OH/ECW and serum NT-proBNP were significantly associated with an increased risk of PH.

Conclusions

A significant number of patients showed increased TRVmax, which was closely related to volume status in CKD5-ND patients. Echocardiography and BIS could be important players in a high possibility of PH detection and treatment in asymptomatic CKD patients. Therefore, these measures could be helpful to improve the cardiac outcomes after initiating renal replacement therapy. Further research may be needed to validate the consistency of this association across other stages of CKD.

Associations of vitamin K status with mortality and cardiovascular events in peritoneal dialysis patients

PURPOSE

Vitamin K deficiency, expressed by a high level of desphospho-uncarboxylated matrix GLA protein (dp-ucMGP), is highly prevalent in dialysis patients. However, the predictive ability of the vitamin K status remains unclear in continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

158 prevalent CAPD patients with a median level of dp-ucMGP of 1093 (752, 1485) pmol/L were enrolled. Patient outcomes including all-cause mortality and cardiovascular events (CVEs) were recorded during follow-up. Survival curves were performed using Kaplan-Meier method, and the influences of dp-ucMGP on outcomes were analyzed by Cox regression models.

RESULTS

A total of 59 deaths and 82 new episodes of CVEs occurred during median follow-up of 31.4 ± 13.1 months (range: 3.8-48.0 months). Kaplan-Meier analysis revealed patients with higher dp-ucMGP levels (≥ 1093 pmol/L) had an increased risk for both mortality (P = 0.005) and CVEs (P < 0.001). Multivariable Cox regression confirmed that higher dp-ucMGP levels increase the mortality risk [hazard ratio (HR), 1.763; 95% CI 1.045-3.291] and CVEs (HR, 1.846; 95% CI 1.074-3.172). For every 100 pmol/L increase in serum dp-ucMGP, the adjusted HRs for mortality and CVEs were 1.054 (95% CI 1.008-1.106) and 1.034 (95% CI 1.012-1.089), respectively.

CONCLUSIONS

Vitamin K deficiency, as expressed by high dp-ucMGP levels, showed independently associations with mortality and CVEs in CAPD patients.

Prevalence of pulmonary hypertension in peritoneal dialysis patients: a meta-analysis

PURPOSE

Recent epidemiological evidence indicates an association between peritoneal dialysis (PD) patients and pulmonary hypertension (PH). However, the true prevalence of PH associated with PD has not been well described. So we conducted a meta-analysis to summarize the point prevalence of PH in adults with PD.

METHODS

PubMed, EMBASE, the Cochrane Collaboration, and the reference lists of relevant articles were searched to identify eligible studies. We used a random-effect meta-analysis model to estimate the prevalence of PH. We also performed sensitivity analyses and assessments of publishing bias.

RESULTS

Fourteen observational studies (n = 1483 participants) were included in this meta-analysis. The result of analysis in random-effect model showed that the pooled prevalence was 21% (95% CI 16-28), with significant heterogeneity between these studies (I² = 84%, p < 0.01). Sensitivity analysis further demonstrated the results to be robust. Besides, the Egger's test (p = 0.287) showed no significant publication bias.

CONCLUSIONS

PH is highly prevalent in patients with PD. Further studies are encouraged to definitively clarify the relationship between PH and PD.

Pulmonary Hypertension, Mortality, and Cardiovascular Disease in CKD and ESRD Patients: A Systematic Review and Meta-analysis

BACKGROUND

Pulmonary hypertension is common in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) and may be associated with poor outcomes. The magnitude of the association between pulmonary hypertension and mortality is uncertain due to the small size and variable findings of observational studies.

STUDY DESIGN

Systematic review and meta-analysis of observational studies using subgroup analyses and metaregression.

SETTING & POPULATION

Patients with ESRD or earlier stages of CKD.

SELECTION CRITERIA FOR STUDIES

Observational studies reporting clinical outcomes in patients with co-existing pulmonary hypertension and CKD or ESRD identified using a systematic search of PubMed and Embase.

PREDICTOR

Pulmonary hypertension diagnosed by Doppler echocardiography.

OUTCOMES

All-cause mortality, cardiovascular mortality, and cardiovascular events.

RESULTS

16 studies, with 7,112 patients with an overall pulmonary hypertension prevalence of 23%, were included. Pulmonary hypertension was associated with increased risk for all-cause mortality among patients with CKD (relative risk [RR], 1.44; 95% CI, 1.17-1.76), with ESRD receiving maintenance dialysis (RR, 2.32; 95% CI, 1.91-2.83), and with a functioning kidney transplant (RR, 2.08; 95% CI, 1.35-3.20). Pulmonary hypertension was associated with increased risk for cardiovascular events in patients with CKD (RR, 1.67; 95% CI, 1.07-2.60) and ESRD receiving dialysis (RR, 2.33; 95% CI, 1.76-3.08). There was an association between pulmonary hypertension and increased risk for cardiovascular mortality in patients with CKD or ESRD (RR, 2.20; 95% CI, 1.53-3.15).

LIMITATIONS

Heterogeneity of included studies, possibility of residual confounding, unavailability of individual patient-level data, and possibility of outcome reporting bias.

CONCLUSIONS

Pulmonary hypertension is associated with a substantially increased risk for death and cardiovascular events in patients with CKD and ESRD. Risk is higher in patients with ESRD receiving dialysis compared with patients with CKD stages 1 to 5. Understanding the effect of interventions to lower pulmonary artery pressure on the survival of these patents awaits their evaluation in randomized controlled trials.

Elevated levels of serum sclerostin are linked to adverse cardiovascular outcomes in peritoneal dialysis patients

PURPOSE

To investigate the correlation between elevated serum sclerostin levels and chronic kidney disease outcomes for patients receiving peritoneal dialysis (PD).

METHODS

We performed a prospective observational study in stable PD patients. Serum sclerostin levels were determined via enzyme immunoassay, and median levels of sclerostin were used to divide patients into high and low sclerostin groups. New-onset cardiovascular events (CVEs) and cardiovascular mortality were evaluated during a 6-year follow-up period.

RESULTS

Ninety-eight patients [mean age 52.5 ± 10.9 years, 49% males, 21.4% diabetic, median dialysis vintage 40.7 (range 17.9-72.2) months] were recruited. Compared with those in the low sclerostin group, patients in the high sclerostin group demonstrated higher levels of total-cholesterol, NT-proBNP, and osteoprotegerin (all P < 0.05). During the 6-year study period, 25 CVEs and 17 cardiovascular deaths occurred in the high sclerostin group, whereas 11 CVEs and four cardiovascular deaths occurred in the low sclerostin group. A Cox regression analysis determined that high sclerostin levels significantly increased the risk for CVEs (HR 2.475, 95% CI 1.116-5.489, P = 0.026) and cardiovascular death (HR 3.484, 95% CI1.134-10.706, P = 0.029), after multiple adjustments were made.

CONCLUSIONS

Our data suggest that high sclerostin levels may predict the onset of CVEs and cardiovascular mortality among PD patients.

Six-minute walk test predicts all-cause mortality and technique failure in ambulatory peritoneal dialysis patients

AIM

This study investigated the associated factors of 6-min walk test (6MWT) and its predictive value of outcome in patients undergoing peritoneal dialysis (PD).

METHODS

This is a single centre prospective observational cohort study. Stable ambulatory PD patients in our centre between 1 May 2010 and 30 April 2011 were enrolled in this study. All included subjects performed 6MWT, and 6-min walk distances (6MWDs) were recorded. Patients were divided into two groups according to 6MWD and prospectively followed up until death, cessation of PD or to the end of the study (30 September 2012).

RESULTS

A total of 145 patients were enrolled, including 63 (43%) males. Multiple stepwise regression showed that age (β = -0.295, P = 0.001), diastolic blood pressure (DBP) (β = 0.292, P = 0.001), left ventricular ejection fraction (LVEF) (β = 0.198, P = 0.019) were independently associated with lower 6MWD. By the end of the study, six (8%) patients died in long 6MWD group while 15 (20%) died in the short 6MWD group, a significantly lower patient survival was observed in short 6MWD group (Log-rank = 4.983, P = 0.026). Patients with short 6MWD also showed inferior technique survival (Log-rank = 4.838, P = 0.028). There was no significant difference in peritonitis-free survival between the two groups (Log-rank = 0.801, P = 0.371). However, more patients in short 6MWD group had been transferred to hemodialysis due to peritonitis (25% vs 4.2%, P = 0.013).

CONCLUSION

Age, diastolic blood pressure, LVEF are independent associated factors of 6MWD in patients undergoing PD. Having the advantages of easy applicability and safety, 6MWT may be proposed as an important predictor of outcome in ambulatory PD patients.

Association of Body Mass Index and Body Mass Index Change with Mortality in Incident Peritoneal Dialysis Patients

Although high body mass index (BMI) appears to confer a survival advantage in hemodialysis patients, the association of BMI with mortality in continuous ambulatory peritoneal dialysis (CAPD) patients is uncertain. We enrolled incident CAPD patients and BMI was categorized according to World Health Organization classification for Asian population. BMI at baseline and one year after the initiation of peritoneal dialysis (PD) treatment was assessed to calculate the BMI change (∆BMI). Patients were split into four categories according quartiles of ∆BMI. Kaplan-Meier method and Cox regression proportional hazard analysis were performed to assess the association of BMI on outcomes. A total of 1263 CAPD patients were included, with a mean age of 47.8 ± 15.0 years, a mean BMI of 21.58 ± 3.13 kg/m². During a median follow-up of 25.3 months, obesity was associated with increased risk for cardiovascular diseases (CVD) death (adjusted hazard ratio (AHR) 2.01; 95% CI 1.14, 3.54), but not all-cause mortality. Additionally, patients with more BMI decline (>0.80%) during the first year after CAPD initiation had an elevated risk for both all-cause (AHR: 2.21, 95% CI 1.23-3.95) and CVD mortality (AHR 2.31, 95% CI 1.11, 4.84), which was independent of baseline BMI values.