Prevalence, Predictors, and Outcomes of Pulmonary Hypertension in CKD

Higher sclerostin is associated with pulmonary hypertension in pre-dialysis end-stage kidney disease patients: a cross-sectional prospective observational cohort study

BACKGROUND

Pulmonary hypertension (PH) is a complication of chronic kidney disease (CKD) that contributes to mortality. Sclerostin, a SOST gene product that reduces osteoblastic bone formation by inhibiting Wnt/β-catenin signaling, is involved in arterial stiffness and CKD-bone mineral disease, but scanty evidence to PH. This study explored the relationship between sclerostin and PH in CKD 5, pre-dialysis end-stage kidney disease (ESKD) patients.

METHODS

This cross-sectional prospective observational cohort study included 44 pre-dialysis ESKD patients between May 2011 and May 2015. Circulating sclerostin levels were measured using an enzyme-linked immunosorbent assay. PH was defined as an estimated pulmonary artery systolic pressure > 35 mmHg on echocardiography.

RESULTS

Patients with higher sclerostin levels ≥ 218.18pmol/L had echocardiographic structural cardiac abnormalities, especially PH (P < 0.01). On multivariate logistic analysis, sclerostin over 218.19pmol/L was significantly associated with PH (odds ratio [OR], 41.14; 95% confidence interval [CI], 4.53-373.89, P < 0.01), but multivariate Cox regression analysis showed the systemic vascular calcification score over 1 point (Hazard ratio [HR] 11.49 95% CI 2.48-53.14, P = 0.002) and PH ([HR] 5.47, 95% CI 1.30-23.06, P = 0.02) were risk factors for all-cause mortality in pre-dialysis ESKD patients.

CONCLUSIONS

Serum sclerostin and PH have a positive correlation in predialysis ESKD patients. The higher systemic vascular calcification score and PH have an association to increase all-cause mortality in pre-dialysis ESKD patients.

Frequency of Pulmonary Hypertension and Its Associated Risk Factors in End-Stage Renal Disease (ESRD) Patients on Maintenance Hemodialysis

Introduction Pulmonary hypertension (PH) is a recognized complication in patients with end-stage renal disease (ESRD undergoing maintenance hemodialysis (MHD). PH is commonly found in patients with chronic kidney disease (CKD) and ESRD. PH is associated with increased morbidity and mortality in patients with CKD. Methodology This cross-sectional study aimed to assess the prevalence of PH and its associated risk factors in MHD patients. A total of 220 ESRD patients on MHD patients at The Kidney Center, Karachi, Pakistan, aged 18-70 were included. Patients with chronic obstructive lung disease, valvular heart disease, and obstructive sleep apnea were excluded, as these conditions can be responsible for PH. PH was evaluated by echocardiography (ECHO), which was performed by a cardiologist. Results The mean age was 50.65 ± 14.4 years, with 131 (59.5%) males and 89 (40.5%) females. The average duration on hemodialysis was 5.3 ± 2.8 years. Hypertension (89.5%) and ischemic heart disease (24.1%) were prominent comorbidities. Hypertensive nephropathy (42.7%) was the leading cause of ESRD. Left ventricular hypertrophy was mild in most cases (85.5%), whereas regional wall motion abnormality (RWMA) was common (67.3%). The average pulmonary artery pressure was 35.2 ± 15.3 mmHg. Out of 220 patients, 109 patients (49.8%) of them had mild PH, nine patients (4.1%) had severe PH, and 72 patients (32.7%) had moderate PH. Associations between PH and various factors were examined. RWMA, left ventricular hypertrophy, and left ventricular ejection fraction were significantly associated with PH (p < 0.001). Serum calcium and albumin levels were also associated with PH severity (p < 0.05). Other demographic and laboratory parameters did not show a significant association. Conclusion This study highlights the prevalence of PH in MHD patients and identifies associated risk factors. Understanding these associations can aid in better managing PH in ESRD patients.

The impact of vascular access location on pulmonary arterial pressure in chronic kidney disease patients undergoing hemodialysis

BACKGROUND AND AIM

It is feared that among chronic kidney disease patients undergoing hemodialysis, arteriovenous fistula (AVF) itself could contribute to pulmonary hypertension (PH). The impact of AVF location on PH is yet to be assessed. We hypothesize that patients with proximal AVF have higher access blood flow and hence higher pulmonary arterial systolic pressure (PASP) than those with distal AVF. We aimed to compare the PASP between patients with proximal and distal AVF.

METHODS

In this cross-sectional study, PASP was estimated using Doppler echocardiography and blood flow in the AVF was assessed by Doppler ultrasound. PASP was modeled by multivariate linear regression. AVF location was the primary exposure of interest.

RESULTS

Out of 89 patients undergoing hemodialysis, 72 (81%) had PH defined as PASP >35 mmHg. The mean blood flow in proximal and distal AVF was, respectively, 1240 and 783 mL/min (mean difference 457 mL/min, p < 0.001). Mean PASP in patients with proximal AVF was 16.6 mmHg higher than those with distal AVF (p < 0.001, 95% CI 8.3-24.9). There was a positive correlation between access blood flow and PASP (r = 0.28, p = 0.007). If access blood flow was included as a covariate in the multivariate model, the association between AVF location and PASP ceased to exist.

CONCLUSION

Patients with proximal AVF have a significantly higher PASP than those with distal AVF, and this could be attributed to the higher blood flow in proximal AVF compared to distal AVF.

FGF23 and klotho at the intersection of kidney and cardiovascular disease

Cardiovascular disease is the leading cause of death in patients with chronic kidney disease (CKD). As CKD progresses, CKD-specific risk factors, such as disordered mineral homeostasis, amplify traditional cardiovascular risk factors. Fibroblast growth factor 23 (FGF23) regulates mineral homeostasis by activating complexes of FGF receptors and transmembrane klotho co-receptors. A soluble form of klotho also acts as a 'portable' FGF23 co-receptor in tissues that do not express klotho. In progressive CKD, rising circulating FGF23 levels in combination with decreasing kidney expression of klotho results in klotho-independent effects of FGF23 on the heart that promote left ventricular hypertrophy, heart failure, atrial fibrillation and death. Emerging data suggest that soluble klotho might mitigate some of these effects via several candidate mechanisms. More research is needed to investigate FGF23 excess and klotho deficiency in specific cardiovascular complications of CKD, but the pathophysiological primacy of FGF23 excess versus klotho deficiency might never be precisely resolved, given the entangled feedback loops that they share. Therefore, randomized trials should prioritize clinical practicality over scientific certainty by targeting disordered mineral homeostasis holistically in an effort to improve cardiovascular outcomes in patients with CKD.

Associations between eGFR and albuminuria with right ventricular measures: the MESA-Right Ventricle study

Background

Chronic kidney disease (CKD) is associated with an increased risk of pulmonary hypertension, which may lead to right ventricular (RV) pressure overload and RV dysfunction. However, the presence of subclinical changes in RV structure or function in early CKD and the influence of these changes on mortality are not well studied. We hypothesized that early CKD, as indicated by elevated albuminuria or mild reductions in estimated glomerular filtration rate (eGFR), is associated with greater RV dilation and RV mass.

Methods

We included 4063 participants (age 45-84 years) without baseline clinical cardiovascular disease from the Multi-Ethnic Study of Atherosclerosis. The associations of baseline creatinine-cystatin C-based eGFR and albuminuria with cardiac magnetic resonance-derived RV measures (2000-02) were examined cross-sectionally with linear regression models. Cox regression models were used to examine whether RV parameters modified the associations of eGFR and albuminuria with all-cause mortality.

Results

Participants with reductions in eGFR primarily within the 60-89 mL/min/1.73 m2 category had smaller RV end-diastolic and end-systolic volumes and stroke volume (all adjusted P-trends <.001) than those with eGFR ≥90 mL/min/1.73 m2, an association that was predominantly seen in participants with albuminuria below 30 mg/g creatinine. Albuminuria was more strongly associated with death among those with lower RV volumes (P-values for interaction <.03).

Conclusions

Among community-dwelling adults, reductions in eGFR primarily within the normal range were associated with smaller RV volumes and the association of albuminuria with worse survival was stronger among those with smaller RV volumes. Further studies are needed to elucidate the underlying mechanistic pathways that link kidney measures and RV morphology.

Development and Validation of a Nomogram for Predicting All-Cause Mortality in Patients with Hemodialysis Having Pulmonary Hypertension

INTRODUCTION

Patients with end-stage renal disease receiving hemodialysis (HD) have a high morbidity and mortality rate associated with pulmonary hypertension (PH). A nomogram was developed to predict all-cause mortality in HD patients with PH. In this study, we aimed to validate the usefulness of this nomogram.

METHODS

A total of 274 HD patients with PH were hospitalized at the Affiliated Hospital of Xuzhou Medical University between January 2014 and June 2019 and followed up for 3 years. Echocardiography detected PH when the peak tricuspid regurgitation velocity (TRV) was more than 2.8 m/s. To evaluate the all-cause mortality for long-term HD patients with PH, Cox regression analysis was performed to determine the factors of mortality that were included in the prediction model. Next, the area under the receiver-operating characteristic curve (AUC-ROC) was used to assess the predictive power of the model. Calibration plots and decision curve analysis (DCA) were used to assess the accuracy of the prediction results and the clinical utility of the model.

RESULTS

The all-cause mortality rate was 29.20% throughout the follow-up period. The nomogram comprised six commonly available predictors: age, diabetes mellitus, cardiovascular disease, hemoglobin, left ventricular ejection fraction, and TRV. The 1-year, 2-year, and 3-year AUC-ROC values were 0.842, 0.800, and 0.781, respectively. The calibration curves revealed excellent agreement with the nomogram, while the DCA demonstrated favorable clinical practicability.

CONCLUSION

The first developed nomogram for predicting all-cause mortality in HD patients with PH could guide clinical decision-making and intervention planning.

Cardiac Structure and Function and Subsequent Kidney Disease Progression in Adults With CKD: The Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVE

Heart-kidney crosstalk is recognized as the cardiorenal syndrome. We examined the association of cardiac function and structure with the risk of kidney failure with replacement therapy (KFRT) in a chronic kidney disease (CKD) population.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

3,027 participants from the Chronic Renal Insufficiency Cohort Study.

EXPOSURE

Five preselected variables that assess different aspects of cardiac structure and function: left ventricular mass index (LVMI), LV volume, left atrial (LA) area, peak tricuspid regurgitation (TR) velocity, and left ventricular ejection fraction (EF) as assessed by echocardiography.

OUTCOME

Incident KFRT (primary outcome), and annual estimated glomerular filtration rate (eGFR) slope (secondary outcome).

ANALYTICAL APPROACH

Multivariable Cox models and mixed-effects models.

RESULTS

The mean age of the participants was 59±11 SD years, 54% were men, and mean eGFR was 43±17mL/min/1.73m2. Between 2003 and 2018 (median follow-up, 9.9 years), 883 participants developed KFRT. Higher LVMI, LV volume, LA area, peak TR velocity, and lower EF were each statistically significantly associated with an increased risk of KFRT, with corresponding HRs for the highest versus lowest quartiles (lowest vs highest for EF) of 1.70 (95% CI, 1.27-2.26), 1.50 (95% CI, 1.19-1.90), 1.43 (95% CI, 1.11-1.84), 1.45 (95% CI, 1.06-1.96), and 1.26 (95% CI, 1.03-1.56), respectively. For the secondary outcome, participants in the highest versus lowest quartiles (lowest vs highest for EF) had a statistically significantly faster eGFR decline, except for LA area (ΔeGFR slope per year, -0.57 [95% CI, -0.68 to-0.46] mL/min/1.73m2 for LVMI, -0.25 [95% CI, -0.35 to-0.15] mL/min/1.73m2 for LV volume, -0.01 [95% CI, -0.12 to-0.01] mL/min/1.73m2 for LA area, -0.42 [95% CI, -0.56 to-0.28] mL/min/1.73m2 for peak TR velocity, and -0.11 [95% CI, -0.20 to-0.01] mL/min/1.73m2 for EF, respectively).

LIMITATIONS

The possibility of residual confounding.

CONCLUSIONS

Multiple aspects of cardiac structure and function were statistically significantly associated with the risk of KFRT. These findings suggest that cardiac abnormalities and incidence of KFRT are potentially on the same causal pathway related to the interaction between hypertension, heart failure, and coronary artery diseases.

PLAIN-LANGUAGE SUMMARY

Heart disease and kidney disease are known to interact with each other. In this study, we examined whether cardiac abnormalities, as assessed by echocardiography, were linked to the subsequent progression of kidney disease among people living with chronic kidney disease (CKD). We found that people with abnormalities in heart structure and function had a greater risk of progression to advanced CKD that required kidney replacement therapy and had a faster rate of decline in kidney function. Our study indicates the potential role of abnormal heart structure and function in the progression of kidney disease among people living with CKD.

Impact of Lung Disease on COVID-19 Health Outcomes in People Living With HIV

Introduction COVID-19 most commonly causes pulmonary/lung infection, and these pulmonary diseases can complicate HIV infection. Underlying pulmonary diseases in people living with HIV (PLWH) could affect health outcomes if infected with COVID-19. Therefore, this study was designed to determine the impact of pulmonary diseases on the health outcomes of PLWH that were infected with COVID-19. Materials and methods We conducted a retrospective study to assess the impact of superimposed COVID-19 infection on pre-existing lung pathologies in patients living with human immunodeficiency virus (HIV) infection using data from the Minnesota Fairview network from January 1, 2020 to December 31, 2022. Ordinal logistic regressions were used to determine the effect of lung comorbidities on COVID-19 severity, COVID-19-specific mortality, and all-cause mortality, adjusting for patient age and gender.  Results Two hundred sixteen PLWH tested positive for COVID-19. 24.54% of these patients had one or more pulmonary diseases, including asthma, chronic obstructive pulmonary disease (COPD), and other lung diseases (interstitial lung diseases and pulmonary hypertension). The severity of COVID-19 outcomes was evaluated by the ranking of patients' medical records of testing positive, admitted to the hospital, being admitted to the ICU, and death. COVID-19-specific and all-cause mortality were evaluated separately. PLWH with underlying asthma or COPD was not associated with increased all-cause or COVID-19-specific mortality. Interstitial lung disease or pulmonary hypertension was significantly associated with poor health outcomes for COVID-19-specific mortality and all-cause mortality (Fisher's Exact p-value <0.001), with ICU admissions accounting for the most impact. Using the multivariate models, interstitial lung disease and pulmonary hypertension was significantly associated with an increased risk of more severe COVID-19 outcomes and COVID-19-specific mortality (OR=6.6153, CI=2.5944, 17.0795, p-value < 0.001). Interstitial lung disease and pulmonary hypertension were also significantly associated with an increased risk of more severe COVID-19 outcomes and all-cause mortality (OR=​​5.0885, CI=2.0590, 12.5542, p-value < 0.001). Conclusions To mitigate the poor outcomes associated with interstitial lung diseases and pulmonary hypertension in PLWH due to COVID-19, healthcare providers must educate their patients about safety measures against the COVID-19 vaccine. They can also encourage the COVID-19 vaccine uptake among their eligible patients.

Excess risk of cardiovascular events in patients in the United States vs. Japan with chronic kidney disease is mediated mainly by left ventricular structure and function

While patients receiving dialysis therapy in the United States are more likely to develop cardiovascular disease (CVD) than those in Japan, direct comparisons of patients with predialysis chronic kidney disease (CKD) are rare. To study this, we compared various outcomes in patients with predialysis CKD using data from the Chronic Renal Insufficiency Cohort (CRIC) and CKD Japan Cohort (CKD-JAC) studies and determined mediators of any differences. Candidate mediators included left ventricular (LV) indices assessed by echocardiography. Among 3125 CRIC and 1097 CKD-JAC participants, the mean LV mass index (LVMI) and ejection fraction (EF) were 55.7 and 46.6 g/m2 and 54% and 65%, respectively (both significant). The difference in body mass index (32 and 24 kg/m2, respectively) largely accounted for the differences in LVMI and C-reactive protein levels across cohorts. Low EF and high LVMI were significantly associated with subsequent CVD in both cohorts. During a median follow-up of five years, CRIC participants were at higher risk for CVD (adjusted hazard ratio [95% confidence interval]: 3.66 [2.74-4.89]) and death (4.69 [3.05-7.19]). A three-fold higher C-reactive protein concentration and higher phosphate levels in the United States cohort were moderately strong mediators of the differences in CVD. However, echocardiographic parameters were stronger mediators than these laboratory measures. LVMI, EF and their combination mediated the observed difference in CVD (27%, 50%, and 57%, respectively) and congestive heart failure (33%, 62%, and 70%, respectively). Thus, higher LV mass and lower EF, even in the normal range, were found to be predictive of CVD in CKD.

Lung Dysfunction and Chronic Kidney Disease: A Complex Network of Multiple Interactions

Chronic kidney disease (CKD) is a progressive disease that affects > 10% of the total population worldwide or >800 million people. CKD poses a particularly heavy burden in low- and middle-income countries, which are least able to cope with its consequences. It has become one of the leading causes of death worldwide and is one of the few non-communicable diseases where the number of related deaths has increased over the last two decades. The high number of people affected, and the significant negative impact of CKD should be a reason to increase efforts to improve prevention and treatment. The interaction of lung and kidney leads to highly complex and difficult clinical scenarios. CKD significantly affects the physiology of the lung by altering fluid homeostasis, acid-base balance and vascular tone. In the lung, haemodynamic disturbances lead to the development of alterations in ventilatory control, pulmonary congestion, capillary stress failure and pulmonary vascular disease. In the kidney, haemodynamic disturbances lead to sodium and water retention and the deterioration of renal function. In this article, we would like to draw attention to the importance of harmonising the definitions of clinical events in pneumology and renal medicine. We would also like to highlight the need for pulmonary function tests in routine clinical practise for the management of patients with CKD, in order to find new concepts for pathophysiological based disease-specific management strategies.

Assessment of Pulmonary Hypertension in Chronic Kidney Disease Patients using Doppler Echocardiography

Background

The incidence of chronic kidney disease (CKD) is increasing globally and is associated with significant morbidity and mortality related to the cardiovascular system. There is limited data on pulmonary hypertension (PH) in CKD patients, especially from developing and underdeveloped countries. PH leads to hypoxia which is a significant cause of dyspnea in CKD patients with or without pulmonary edema. Hence, we planned this study to assess the PH in CKD patients using two-dimensional (2D) color Doppler echocardiography.

Materials and Methods

This is an observational cross-sectional study. A total of 100 CKD patients on hemodialysis or conservative management were enrolled in the study. Following the collection of demographic data, and routine/specific investigations, these patients were assessed for PH using 2D color Doppler echocardiography.

Results

PH was found in 47% of patients with CKD. Left ventricular (LV) hypertrophy, systolic and diastolic dysfunction, dilated right atrium/right ventricular and left atrial/LV chambers, and valvular hypertrophy were other echocardiography findings recorded in these patients. Low hemoglobin levels, high urea/creatinine levels, and duration of hemodialysis in CKD patients were found to be significantly associated with the presence of PH.

Conclusion

The majority of CKD patients have PH at various stages of disease-causing unexplained dyspnea in these patients. PH is common in end-stage CKD as compared to patients with a less severe stage of CKD. Hence, CKD patients should be evaluated for PH, especially in the presence of intractable dyspnea.

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.

Development and validation of a risk nomogram model for predicting pulmonary hypertension in patients with stage 3-5 chronic kidney disease

OBJECTIVES

The occurrence of pulmonary arterial hypertension (PAH) can greatly affect the prognosis of patients with chronic kidney disease (CKD). We aimed to construct a nomogram to predict the probability of PAH development in patients with stage 3-5 CKD to guide early intervention and to improve prognosis.

METHODS

From August 2018 to December 2021, we collected the data of 1258 patients with stage 3-5 CKD hospitalized at the Affiliated Hospital of Xuzhou Medical University as a training set and 389 patients hospitalized at Zhongda Hospital as a validation set. These patients were divided into PAH and N-PAH groups with pulmonary arterial systolic pressure ≥ 35 mmHg as the cutoff. The results of univariate and multivariate logistic regression analyses were used to establish the nomogram. Then, areas under the receiver operating characteristic curve (AUC-ROCs), a calibration plot, and decision curve analysis (DCA) were used to validate the nomogram.

RESULTS

The nomogram included nine variables: age, diabetes mellitus, hemoglobin, platelet count, serum creatinine, left ventricular end-diastolic diameter, left atrial diameter, main pulmonary artery diameter and left ventricular ejection fraction. The AUC-ROCs of the training set and validation set were 0.801 (95% confidence interval (CI) 0.771-0.830) and 0.760 (95% CI 0.699-0.818), respectively, which showed good discriminative ability of the nomogram. The calibration diagram showed good agreement between the predicted and observed results. DCA also demonstrated that the nomogram could be clinically useful.

CONCLUSION

The evaluation of the nomogram model for predicting PAH in patients with CKD based on risk factors showed its ideal efficacy. Thus, the nomogram can be used to screen for patients at high risk for PAH and has guiding value for the subsequent formulation of prevention strategies and clinical treatment.

Echocardiographic changes after arteriovenous fistula creation in hemodialysis patients

BACKGROUND

Pulmonary hypertension (PH) is common in end-stage renal disease (ESRD) patients and is associated with increased all-cause and cardiovascular mortality in this group. There is scarce data on the long-term effect of arteriovenous fistula (AVF) creation on pulmonary hypertension (PH) and the reflected changes in echocardiographic measurements.

MATERIALS AND METHODS

This is a retrospective study of 54 patients who underwent AVF creation between 2009 and 2014 and with echocardiographic evaluations before and after surgery. We analyzed pairwise changes in right ventricular systolic pressure (RVSP), right atrial pressure (RAP) during systole, left ventricular mass (LVM), tricuspid regurgitation (TR), mitral E/E' ratio, and ejection fraction (EF), as well as the factors that predicted change in RVSP after surgery.

RESULTS

The median time for the preoperative echocardiogram was 0.3 years (interquartile range (IQR) 0.2 - 0.7 years) prior to AVF creation, while the follow-up echo was done 1.3 (0.6 - 2.1) years after surgery. 67% of the patients had RVSP &gt; 37 mmHg at baseline. There was a significant reduction in RVSP after AVF creation compared to baseline (median 33 (IQR 26 - 43) vs. 46 mmHg, p = 0.0015), with 59% of the patients experiencing a decrease and 19% remaining stable. There were also significant decreases in LVM (201 (143 - 256) vs. 215 (163 - 276), p = 0.045) and RAP systole (10 (10 - 15) vs. 3 (3 - 8); p &lt; 0.001) after surgery. Higher preoperative weight (p = 0.038) and RVSP (p = 0.006), and use of loop diuretics (p = 0.015) were significantly associated with improvement in RVSP after AVF creation.

CONCLUSION

Our results suggest that AVF creation is associated with a significant reduction or stable measurements of RVSP in the ESRD population, likely due to an improvement in volume status.

Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases

Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.

Cardiopulmonary exercise testing to observe subclinical abnormalities in cardiopulmonary function in patients undergoing peritoneal dialysis

BACKGROUND

Decreased cardiorespiratory fitness (CRF) related to cardiopulmonary function increases the risk of cardiovascular disease in patients with end-stage kidney disease. Thus, early detection of the cause of impaired cardiopulmonary function in patients undergoing peritoneal dialysis (PD) is of important clinical significance.

METHODS

In this cross-sectional study, Symptom-restricted cardiopulmonary exercise testing (CPET) was performed in 30 patients undergoing PD and in 23 age- and sex-matched healthy control subjects.A fixed workload was added every minute until fatigue, and breath-by-breath respiratory gas was analyzed with an automated gas analyzer at 10-second intervals.

RESULTS

The peak oxygen uptake ( 16.39±0.83 vs 25.77±1.33 ml/kg/min p<0.001) and the oxygen uptake at the anerobic threshold of patients undergoing PD (9.61±0.34 vs 14.55± 0.64 ml/kg/min; p<0.001) were lower than in healthy control subjects, and both of these parameters correlated with body mass index and left atrial dimension. A steeper minute ventilation / carbon dioxide production slope (27.20±0.68 vs 24.29±0.69；p<0.01) and a lower end-tidal carbon dioxide partial pressure (37.93±0.54 vs 41.27±0.83mmHg；p<0.05) were observed in patients undergoing PD. The oxygen pulse and oxygen uptake efficiency slope was smaller in patients undergoing PD. The Maximum heart rate (126.07±4.01 vs 149.96±5.29 bpm；p<0.01) and 1-minute heart rate recovery (13.93±1.52 vs 24.39±1.61bpm；p<0.01) were also lower in patients undergoing PD.

CONCLUSION

Subclinical cardiopulmonary dysfunction may exist in patients with PD, and a reduction in CRF in patients undergoing PD is affected by both central and peripheral functions. CPET has potential value in revealing the mechanism of impaired CRF and in discovering subclinical abnormalities in cardiopulmonary function. This article is protected by copyright. All rights reserved.

Pulmonary hypertension among maintenance hemodialysis patients in Somalia: a hospital-based observational study

BACKGROUND

This study aims to examine the prevalence and related factors of pulmonary hypertension (PHT) in patients on hemodialysis (HD) at the only referral institution in Somalia. A total of one hundred and forty-three patients  who had received regular HD therapy for at least three months and underwent transthoracic echocardiography (TTE) were included in the study. Patients with a systolic pulmonary artery pressure (sPAP) value > 35 mmHg at rest on TTE were considered having PHT. The relationship of TTE parameters, demographic, and clinic characteristics of participants with PHT were evaluated.

RESULTS

The number of patients with PHT was 73 (51%). The mean age was 54.2 ± 18.4 years. The majority of patients were 65 years of age or older. (n: 46, 32.2%) and 65 (45.5%) were male. Median sPAP was found to be 35 mmHg. Systolic pulmonary artery pressure was positively correlated with right atrium (RA) diameter (r: 0.6, p < 0.001) and negatively correlated with left ventricular ejection fraction (LVEF) (r: - 0.4, p < 0.001). In addition, LVEF, RA diameter, presence of pericardial effusion (PE) were found to be independent predictors of PHT.

CONCLUSIONS

Pulmonary hypertension has a relatively high prevalence in end-stage renal disease (ESRD) patients on regular HD. Besides, the presence of PE and certain right and left heart parameters were independently associated with PHT.

Progression of Chronic Kidney Disease and All-Cause Mortality in Patients with Tricuspid Regurgitation

Aim: The impact of chronic kidney disease (CKD) on patient-related outcomes in patients with tricuspid regurgitation (TR) is well known. However, the impact of the progression of CKD in patients with TR and potentially modifiable risk factors of progressing CKD is unknown. Methods: 444 consecutive adult patients with TR and CKD stage 1−4 admitted in an inpatient setting between January 2010 and December 2017 were included. During a median follow-up of two years, eGFR and survival status were collected. Independent risk factors for CKD progression and all-cause mortality were determined. Patient survival statuses were grouped according to different combinations of the presence or absence of CKD progression and the TR grade. Results: Progression of CKD (OR 2.38 (95% confidence interval 1.30−4.35), p = 0.005), the grade of TR (OR 2.38 (1.41−4.00), p = 0.001) and mitral regurgitation (OR 1.72 (1.20−2.46), p = 0.003) were independent risk factors for all-cause mortality. Haemoglobin at admission (OR 0.80 (0.65−0.99), p = 0.043) and the presence of type 2 diabetes (OR 1.67 (1.02−2.73), p = 0.042) were independent risk factors for CKD progression. The combination of the status of CKD progression and the TR grade showed a stepwise pattern for all-cause mortality (p < 0.001). Patients with CKD progression and TR grade 1 had comparable all-cause mortality with patients without CKD progression but with TR grade 2 or 3. Even in patients with TR grade 1, the risk for all-cause mortality doubled if CKD progression occurred (OR 2.49 (95% CI 1.38−4.47), p = 0.002). Conclusion: CKD progression appears to be a risk factor for all-cause mortality in patients with TR. Anaemia and diabetes are potential modifiers of CKD progression.

A Novel Factor in Determining the Risk of Ischemic Cerebrovascular Events in Patients with Atrial Fibrillation: Pulmonary Hypertension

OBJECTIVES

Pulmonary hypertension (PH) is closely related to clinical decompensation and poor clinical outcomes in atrial fibrillation (AF) patients. However, the association between PH and ischemic cerebrovascular events (ICE) in AF patients has not been investigated. The authors purposed to examine this relationship.

MATERIALS AND METHODS

The researchers conducted an observational study on 371 AF patients between January and November 2021. In line with the European Society of Cardiology guideline recommendations, echocardiographic parameters suggestive of PH were performed. The study population was stratified into two groups based on the presence (n = 98, 31%) or non-presence (n = 219, 69%) of PH. Also, we did logistic regression analyses for the independent predictors of the ICEs in AF patients.

RESULTS

Ischemic cerebrovascular events were significantly more frequent in the PH group than the non-PH group (n = 30, 13% vs. n = 18, 18%, p = 0.03). At univariable analysis, hypertension, diabetes mellitus, PH (OR = 0.23 [95% CI, 0.13-0.41], p = 0.005) and diastolic dysfunction were significantly related to ICE in AF patients. Moreover, at multivariable analysis, age, diabetes mellitus, PH (OR = 0.19 [95% CI, 0.10-0.36], p = 0.01), and diastolic dysfunction were predictive of ICE.

CONCLUSIONS

Pulmonary hypertension is likely associated with ischemic cerebrovascular events in patients with AF, requiring further investigation to determine its association.

The value of ventricular gradient for predicting pulmonary hypertension and mortality in hemodialysis patients

Pulmonary hypertension (PHT) is associated with increased mortality in hemodialysis (HD) patients. The ventricular gradient optimized for right ventricular pressure overload (VG-RVPO) is sensitive to early changes in right ventricular overload. The study aimed to assess the ability of the VG-RVPO to detect PHT and predict all-cause and cardiac mortality in HD patients. 265 selected HD patients were enrolled. Clinical, biochemical, electrocardiographic, and echocardiographic parameters were evaluated. Patients were divided into normal and abnormal VG-RVPO groups, and were followed-up for 3 years. Abnormal VG-RVPO patients were more likely to be at high or intermediate risk for PHT, were older, had longer HD vintage, higher prevalence of myocardial infarction, higher parathormone levels, shorter pulmonary flow acceleration time, lower left ventricular ejection fraction, higher values of left atrial volume index, left ventricular mass index, and peak tricuspid regurgitant velocity. Both all-cause and CV mortality were higher in abnormal VG-RVPO group. In multivariate Cox analysis, VG-RVPO remained an independent and strong predictor of all-cause and CV mortality. In HD patients, abnormal VG-RVPO not only predicts PHT, but also all-cause and CV mortality.

Mortality, Kidney Failure, and Hospitalization Among Medicare Beneficiaries With CKD and Pulmonary Hypertension

RATIONALE & OBJECTIVE

Pulmonary hypertension (PH) is highly prevalent among patients with chronic kidney disease (CKD) not requiring kidney replacement therapy. We studied the associations of PH with mortality, kidney failure, as well as cardiovascular (CV) and non-CV hospitalization among Medicare beneficiaries with a CKD diagnosis.

STUDY DESIGN

Retrospective, observational study using a matched cohort design.

SETTING & PARTICIPANTS

Patients with PH (based on 2 claims within 2 years) and patients without PH matched on CKD stage from the Medicare 5% CKD sample (1996-2016).

PREDICTOR

Presence of pulmonary hypertension.

OUTCOME

Mortality, kidney failure, and all-cause, CV, and non-CV hospitalization.

ANALYTICAL APPROACH

Cox proportional hazards models to assess the association between PH and mortality, adjusting for age, sex, race, and comorbidities. Death was considered as a competing event in Fine-Gray models to assess the association between PH and kidney failure. Negative binomial model was used to evaluate the relationship between PH and all-cause, CV, and non-CV hospitalizations.

RESULTS

30,052 patients with PH and CKD and 150,260 CKD stage-matched patients without diagnosed PH were studied. The median age of the study population was 80.7 years, 57.8% were women, and 10.3% were African Americans. The presence of PH was associated with an increased risk of mortality after 1 (HR, 2.87 [95% CI, 2.79-2.95]), 2-3 (HR, 1.56 [95% CI, 1.51-1.61]), and 4-5 (HR, 1.47 [95% CI, 1.40-1.53]) years of follow-up, and a higher risk of all-cause, CV, and non-CV hospitalization during the same period. PH was also associated with kidney failure in after 1 and 2-3 years but not after 4-5 years of follow-up evaluation. Patients with PH also experienced higher rates of acute kidney injury (AKI), and AKI requiring dialysis support within 30 and 90 days of AKI.

LIMITATIONS

Reliance on billing codes and lack of echocardiogram or right heart catheterization data CONCLUSIONS: Among older Medicare beneficiaries with a CKD diagnosis not requiring kidney replacement therapy, the presence of PH was associated with an increased risk of mortality, kidney failure, and hospitalization. Understanding of the mechanism of these associations, especially the increased risk of kidney failure, requires further study.

An evaluation of roxadustat for the treatment of anemia associated with chronic kidney disease

INTRODUCTION

Anemia is one of the major complications of chronic kidney disease (CKD). Erythropoiesis-stimulating agents (ESAs) have been the mainstay of renal anemia treatment. However, there are several safety drawbacks, and a safer and more effective alternative treatment has been sought.

AREAS COVERED

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) have been developed as a novel orally active therapeutic agent for renal anemia. HIF-PHIs stimulate endogenous EPO and optimize iron utilization. Roxadustat is a first-in-class HIF-PHI for the treatment of anemia in CKD patients approved in China, Japan, South Korea, and Chile. The authors herein evaluate the pharmacology of roxadustat and give their expert perspectives on its use.

EXPERT OPINION

Phase 3 clinical trials have demonstrated that roxadustat effectively increases and maintains hemoglobin (Hb) levels in both nondialysis-dependent and dialysis-dependent CKD patients. Roxadustat also improved iron metabolism and reduced intravenous (IV) iron requirements. However, pooled analyses of phase 3 studies have revealed frequent thromboembolic events in the roxadustat group, which might be attributed to rapid changes in Hb and inadequate iron supplementation. Roxadustat is an attractive alternative treatment especially for patients with ESA hyporesponsive due to impaired iron utilization, and so appropriate selection of target patients and its proper use are crucially important.

Early combination of pulmonary vasodilators prevents chronic kidney disease progression in connective tissue disease-associated pulmonary hypertension

AIM

Pulmonary hypertension (PH) and chronic kidney disease (CKD) are interdependent for their development and exacerbation. We evaluated the effect of PH on CKD progression in patients with connective tissue disease (CTD)-associated PH.

METHODS

We reviewed consecutive patients with CTD who were diagnosed with PH with right heart catheter (RHC) examinations in our hospital. Patients were divided into 2 groups according to the use of vasodilators: monotherapy or combination therapy. We further divided the patients with combination therapy into early and non-early combination groups. Early combination was defined as the addition of the second vasodilator within 1 month after starting the first drug. The clinical course of hemodynamics and CKD progression were compared.

RESULTS

Thirty-eight patients were included in the analysis: 10 were treated with monotherapy and 28 with combination therapy (14 with early and 14 with non-early). At baseline, patients who received combination therapy had a significantly higher mean pulmonary arterial pressure with RHC and a higher right ventricular systolic pressure (RVSP) with echocardiography (P = .04) and showed a greater improvement in RVSP after treatment than those who underwent monotherapy. The incidence of CKD progression was significantly lower in patients who received combination therapy than in those who received monotherapy (P = .05). Among patients who received combination therapy, the early combination group had a lower incidence of CKD progression than the non-early combination group (P = .03).

CONCLUSIONS

Early combination therapy is associated with a lower incidence of CKD progression in patients with CTD-associated PH.

Pulmonary Hypertension in Chronic Kidney Disease

There is a high prevalence of pulmonary hypertension in chronic kidney disease (CKD), with rates increasing as glomerular filtration rate declines. Pulmonary hypertension is associated with a higher risk of cardiovascular events and mortality in non-dialysis-dependent CKD stages 3 to 5, dialysis-dependent CKD, as well as kidney transplant recipients. The pathophysiology of pulmonary hypertension in CKD is multifactorial and includes higher pulmonary capillary wedge pressure caused by ischemic heart disease and cardiomyopathy, higher cardiac output caused by anemia and arteriovenous access used for hemodialysis, as well as potentially higher pulmonary vascular resistance. Treatment should focus on the underlying cause.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Epidemiology, Pathogenesis, and Clinical Approach in Group 5 Pulmonary Hypertension

Pulmonary hypertension (PH) is recognized to be associated with a number of comorbid conditions. Based on these associations, PH is classified into 5 groups, considering common pathophysiologic drivers of disease, histopathologic features, clinical manifestations and course, and response to PH therapy. However, in some of these associated conditions, these characteristics are less well-understood. These include, among others, conditions commonly encountered in clinical practice such as sarcoidosis, sickle cell disease, myeloproliferative disorders, and chronic kidney disease/end stage renal disease. PH in these contexts presents a significant challenge to clinicians with respect to disease management. The most recent updated clinical classification schemata from the 6th World Symposium on PH classifies such entities in Group 5, highlighting the often unclear and/or multifactorial nature of PH. An in-depth review of the state of the science of Group 5 PH with respect to epidemiology, pathogenesis, and management is provided. Where applicable, future directions with respect to research needed to enhance understanding of the clinical course of these entities is also discussed.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Does kidney function matter in pulmonary thromboembolism management?

Cardiovascular circulation and kidney function are closely interrelated. The impairment of renal function is a well-known hazard of increased mortality and morbidity of patients with heart failure or coronary artery disease. Acute pulmonary embolism (APE) impacts pulmonary and systemic circulation, and can severely impair functions of other organs, including kidneys, as a result of hypoxemia and increased venous pressure. Previous studies indicate that renal dysfunction predicts short- and long-term outcomes and can improve the risk assessment in APE. However, renal function should also be cautiously considered during the diagnostic workup because the contrast-induced nephropathy after computed tomography pulmonary angiography is noticed more frequently in APE. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but imminent complication of APE. This condition promotes renal impairment by increasing venous pressure and decreasing glomerular filtration. The renal function improvement and serum creatinine concentration reduction were noted in CTEPH subgroup with glomerular filtration rate ≤ 60 mL/min/1.73 m2 after successful treatment. In this review, we present the essential research results on the kidney function in thromboembolism disease.

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.

Recommendations by the Asian Pacific society of nephrology (APSN) on the appropriate use of HIF-PH inhibitors

Renal anaemia is a common and important complication in patients with chronic kidney disease (CKD). The current standard‐of‐care treatment for renal anaemia in CKD patients involves ensuring adequate iron stores and administration of erythropoietin stimulating agents (ESA). Hypoxia inducible factor (HIF) is a key transcription factor primarily involved in the cellular regulation and efficiency of oxygen delivery. Manipulation of the HIF pathway by the use of HIF‐prolyl hydroxylase inhibitors (HIF‐PHI) has emerged as a novel approach for renal anaemia management. Despite it being approved for clinical use in various Asia‐Pacific countries, its novelty mandates the need for nephrologists and clinicians generally in the region to well understand potential benefits and harms when prescribing this class of drug. The Asian Pacific society of nephrology HIF‐PHI Recommendation Committee, formed by a panel of 11 nephrologists from the Asia‐Pacific region who have clinical experience or have been investigators in HIF‐PHI studies, reviewed and deliberated on the clinical and preclinical data concerning HIF‐PHI. This recommendation summarizes the consensus views of the committee regarding the use of HIF‐PHI, taking into account both available data and expert opinion in areas where evidence remains scarce.

The Asian Pacific society of nephrology HIF‐PHI Recommendation Committee summarizes the consensus views of the committee regarding the use of HIF‐PHI, taking into account both available data and expert opinion in areas where evidence remains scarce.

Congestive nephropathy: a neglected entity? Proposal for diagnostic criteria and future perspectives

Venous congestion has emerged as an important cause of renal dysfunction in patients with cardiorenal syndrome. However, only limited progress has been made in differentiating this haemodynamic phenotype of renal dysfunction, because of a significant overlap with pre-existing renal impairment due to long-term hypertension, diabetes, and renovascular disease. We propose congestive nephropathy (CN) as this neglected clinical entity. CN is a potentially reversible subtype of renal dysfunction associated with declining renal venous outflow and progressively increasing renal interstitial pressure. Venous congestion may lead to a vicious cycle of hormonal activation, increased intra-abdominal pressure, excessive renal tubular sodium reabsorption, and volume overload, leading to further right ventricular (RV) stress. Ultimately, renal replacement therapy may be required to relieve diuretic-resistant congestion. Effective decongestion could preserve or improve renal function. Congestive acute kidney injury may not be associated with cellular damage, and complete renal function restoration may be a confirmatory diagnostic criterion. In contrast, a persistently low renal perfusion pressure might induce renal dysfunction and histopathological lesions with time. Thus, urinary markers may differ. CN is mostly seen in biventricular heart failure but may also occur secondary to pulmonary arterial hypertension and elevated intra-abdominal pressure. An increase in central venous pressure to >6 mmHg is associated with a steep decrease in glomerular filtration rate. However, the central venous pressure range that can provide an optimal balance of RV and renal function remains to be determined. We propose criteria to identify cardiorenal syndrome subgroups likely to benefit from decongestive or pulmonary hypertension-specific therapies and suggest areas for future research.

Association of Pulmonary Hypertension With End-Stage Renal Disease Among the Obese Population

Introduction

Pulmonary hypertension (PH) is a known complication that occurs in patients of end-stage renal disease (ESRD) that have an arteriovenous fistula (AVF) for hemodialysis (HD). It is defined as pulmonary artery pressure (PAP) of greater than 30 mmHg on echocardiography. The presence of PH in ESRD is an independent risk factor and decreases the survival likelihood among HD patients. Unexplained PH is frequently seen in ESRD following AVF.

Obesity can lead to various complications, such as sleep apnea, cardiac complications, pulmonary hypertension, and mortality. Data on the prevalence of coexisting PH and obesity are scarce.

Obese patients often have increased albumin excretion rates (AER) that can lead to early renal impairment and an increase in intraglomerular pressure, which may increase the risk of cardiovascular (CV) morbidity and mortality.

Therefore, the study aimed to evaluate and compare the associated PH and obesity separately and collectively among ESRD patients.

Methods

This comparative cross-sectional study was conducted in a tertiary care public sector hospital with the approval of the medical ethics review board committee.

The study enrolled all consecutive patients with ESRD as defined by having an estimated glomerular filtration rate (GFR) of <15 mL/min/1.7 3 m² from April 2017 till March 2019, who presented to our facility. These patients underwent dialysis twice or thrice a week, each session lasting three to four hours approximately. On initial encounter, trans-thoracic echocardiography (TTE) was done by the cardiologist to diagnose pulmonary hypertension.

In addition, body mass index (BMI) was calculated for all patients, and the patients were categorized into underweight, normal, overweight, or obese. All patients underwent post-dialysis TTE at one hour or when patients were at the optimal dry weight. Systolic PAP and ejection fraction were measured, and pulmonary hypertension was defined as a PAP of 30 mmHg or greater on TTE.

ESRD patients that were diagnosed with PH prior to hemodialysis or had primary PH were excluded from the study. Only ESRD patients developing secondary PH after hemodialysis were included in the study.

The chi-square test was used to see the correlation of gender, ambulation status, smoking status, obesity, pulmonary hypertension, body mass index (BMI), and pulmonary hypertension and obesity combined on the final outcome. A p-value of 0.05 was considered significant. Odds ratio (OR) and relative risk (RR) were calculated for pulmonary hypertension and obesity combined, obesity, and pulmonary hypertension in the final outcome.

Results

The study enrolled 204 patients with a mean age of 46.23 (±20.45 SD) having higher female participation of 108 (52.9%), whereas 96 (47.1%) were males. The average weight of the cohort was 66.78 kg (±22.98 SD) with a mean BMI of 29.91 kg/m² (±13.29SD), 52 (25.5%) patients were underweight, 40 (19.6%) had a normal BMI, 29 (14.2%) were overweight, and 83 (40.7%) patients were obese.

Pulmonary hypertension and obesity combined were observed in 48 (23.5%) of the cases and there was a 4.60 relative risk of death among these individuals, with an odds ratio of 13.35 and a p-value of 0.00.

Conclusion

The study shows a strong synergistic effect of pulmonary hypertension and obesity towards the final survival outcome in ESRD patients who are on hemodialysis.

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.

Pulmonary Hypertension in Patients Starting Peritoneal Dialysis

BACKGROUND

Cardiovascular complications are the major cause of morbidity and mortality in patients with chronic kidney disease (CKD). One such complication is pulmonary hypertension (PH). Its prevalence in patients in peritoneal dialysis (PD) varies from 12.6-41.7% and its related factors are not well known. The main objective of this multicenter study was to determine the prevalence of PH and its risk factors in patients starting in PD.

METHODS

Patients incident in PD were studied. Clinical, biochemical, and PD parameters were evaluated. A transthoracic echocardiography was performed and the evaluated according to the American Society of Echocardiography. Systolic pulmonary artery pressure (sPAP) was calculated with tricuspid regurgitation gradient and PH considered if pulmonary artery pressure was ≥35 mmHg.

RESULTS

There were 105 men and 72 women included in the study (aged 53.7 ± 12.8 vs. 52.9 ± 15.5 years). PH was found in 69 patients (38.98%), they had sPAP of 49.05 ± 13.80 vs. 18.81 ± 11.15 mmg, in patients without PH (p <0.001). Patients with PH tend to be more frequently men than women (42 vs. 35%, p = 0.33), and were younger (51.0 ± 14.9 vs. 55,1 ± 12.8 years; p = 0.05). Risk factor for PH were diastolic dysfunction of the left ventricle (LV) (OR = 1.46, 95% CI 1.094-1.973), left ventricular hypertrophy (LVF) (OR = 2.56, 95% CI 1.29-5.09); and residual renal function (RRF) was a protector factor (OR = 0.78, 95% CI 0.068-0.915).

CONCLUSIONS

Prevalence of PH in patient's incident in PD was 38%. The factors associated with PH were diastolic dysfunction of the LV and LV hypertrophy. RRF was a protector factor.

Associations between echocardiographic findings and prospective changes in residual renal function in patients new to peritoneal dialysis

Although echocardiograms are often performed when peritoneal dialysis is started, associations between commonly reported findings and prospective changes in renal function remain understudied. Ninety-nine of 101 patients in the Trio Trial had transthoracic echocardiograms within 6 months of dialysis initiation, and measurements of residual renal function every six weeks for up to two years. Generalized mixed modelling linear regression in STATA was used to examine associations between left atrial size, left ventricular hypertrophy, left ventricular ejection fraction, right ventricular systolic pressure, and left valvular calcification with subsequent slopes in renal function. After echocardiography (performed a median of 16 days following peritoneal dialysis initiation) right ventricular systolic pressure was associated with faster, while declining left ventricular ejection fraction and valvular calcification were associated with slower declines in residual renal function. Future studies could be conducted to confirm these findings, and identify pathophysiological mechanisms.

Pulmonary Hypertension Subtypes and Mortality in CKD

RATIONALE & OBJECTIVE

Pulmonary hypertension (PH) contributes to cardiovascular disease and mortality in patients with chronic kidney disease (CKD), but the pathophysiology is mostly unknown. This study sought to estimate the prevalence and consequences of PH subtypes in the setting of CKD.

STUDY DESIGN

Observational retrospective cohort study.

SETTING & PARTICIPANTS

We examined 12,618 patients with a right heart catheterization in the Duke Databank for Cardiovascular Disease from January 1, 2000, to December 31, 2014.

EXPOSURES

Baseline kidney function stratified by CKD glomerular filtration rate category and PH subtype.

OUTCOMES

All-cause mortality.

ANALYTICAL APPROACH

Multivariable Cox proportional hazards analysis.

RESULTS

In this cohort, 73.4% of patients with CKD had PH, compared with 56.9% of patients without CKD. Isolated postcapillary PH (39.0%) and combined pre- and postcapillary PH (38.3%) were the most common PH subtypes in CKD. Conversely, precapillary PH was the most common subtype in the non-CKD cohort (35.9%). The relationships between mean pulmonary artery pressure, pulmonary capillary wedge pressure, and right atrial pressure with mortality were similar in both the CKD and non-CKD cohorts. Compared with those without PH, precapillary PH conferred the highest mortality risk among patients without CKD (HR, 2.27; 95% CI, 2.00-2.57). By contrast, in those with CKD, combined pre- and postcapillary PH was associated with the highest risk for mortality in CKD in adjusted analyses (compared with no PH, HRs of 1.89 [95% CI, 1.57-2.28], 1.87 [95% CI, 1.52-2.31], 2.13 [95% CI, 1.52-2.97], and 1.63 [95% CI, 1.12-2.36] for glomerular filtration rate categories G3a, G3b, G4, and G5/G5D).

LIMITATIONS

The cohort referred for right heart catheterization may not be generalizable to the general population. Serum creatinine data in the 6 months preceding catheterization may not reflect true baseline CKD. Observational design precludes assumptions of causality.

CONCLUSIONS

In patients with CKD referred for right heart catheterization, PH is common and associated with poor survival. Combined pre- and postcapillary PH was common and portended the worst survival for patients with CKD.

Characteristics and Outcomes of Patients With Aortic Stenosis and Chronic Kidney Disease

Background We sought to study longer term survival in patients with aortic stenosis ( AS ) and nondialysis chronic kidney disease ( CKD ). Methods and Results We studied 839 patients (aged 78±9 years and 51% male) with CKD and AS on echocardiogram from 2005 to 2012. Longer term all-cause and cardiovascular mortality was compared with a CKD group without AS , propensity matched for age, sex, race, left ventricular ejection fraction and CKD stage. Cox models were used to evaluate all-cause mortality and competing-risks regression models censored at time of aortic valve replacement to evaluate cardiac mortality in patients with AS and CKD . Overall, 511 (61%), 252 (30%), and 76 (9%) patients had CKD stages 3a, 3b, and 4, respectively; 93% had hypertension, 28% had diabetes mellitus, and 37% had coronary artery disease. In total, 185 (22%) had mild AS, 355 (42%) had moderate AS, and 299 (36%) had severe AS (66 symptomatic). Patients with CKD and AS had higher cardiac and all-cause mortality compared with controls with CKD and no AS ( P<0.001). Among patients with AS and CKD , there were 156 (19%) aortic valve replacements and 454 (54%) deaths (203 cardiac deaths) at 4.0±2.3 years of follow-up. Lower estimated glomerular filtration rate (hazard ratio per 10 mL/min per 1.73 m2: 1.18; 95% CI, 1.08-1.29) was associated with increased risk of all-cause mortality but not cardiac mortality (hazard ratio: 1.12; 95% CI, 0.97-1.30; P=0.13). Of patients undergoing aortic valve replacement, 61% had improvement in estimated glomerular filtration rate within 1 year (median percentage change=+2.8% per month). Conclusions Among patients with nondialysis CKD , AS is associated with significantly higher cardiac and all-cause mortality; lower estimated glomerular filtration rate is associated with increased mortality, and aortic valve replacement was associated with improved survival.

Effects of Pulmonary Hypertension and Right Ventricular Function in Short and Long-Term Kidney Function

BACKGROUND

Pulmonary hypertension is not uncommon in patients with renal disease and vice versa; therefore, it influences treatments and outcomes. There is a large body of literature on pulmonary hypertension in patients with kidney disease, its prognostic implications, economic burden, and management strategies. However, the converse, namely the hemodynamic effects of pulmonary hypertension on kidney function (acute and chronic kidney injury) is less studied and described. There is also increasing interest in the effects of pulmonary hypertension on kidney transplant outcomes. The relationship is a complex phenomenon and multiple body systems and mechanisms are involved in its pathophysiology. Although the definition of pulmonary hypertension has evolved over time with the understanding of multiple interplays between the heart, lungs, kidneys, etc; there is limited evidence to provide a specific treatment strategy when kidneys and lungs are affected at the same time. Nevertheless, available evidence appears to support new therapeutics and highlights the importance of individualized approach. There is sufficient research showing that the morbidity and mortality from PH are driven by the influence of the pulmonary hemodynamic dysfunction on the kidneys.

CONCLUSION

This concise review focuses on the effects of pulmonary hypertension on the kidneys, including, the patho-physiological effects of pulmonary hypertension on acute kidney injury, progression of CKD, effects on kidney transplant outcomes, progression of kidney disease in situations such as post LVAD implantation and novel diagnostic indices. We believe a review of this nature will fill in an important gap in understanding the prognostic implication of pulmonary hypertension on renal disease, and help highlight this important component of the cardio-reno-pulmonary axis.

Lung-Kidney Cross-Talk

Awareness of the multifaceted lung and kidney interactions in the critically ill has increased considerably. Cardiogenic and noncardiogenic pulmonary edema represent two entities of pulmonary edema and differ significantly in terms of alveolar fluid clearance. Acute lung injury describes the breakdown of normal lung architecture with development of a high-permeability noncardiogenic pulmonary edema resulting from an inflammation/oxidant-mediated injury to the alveolar-capillary barrier and downregulation of the epithelial active ion transport system. Acute kidney injury is the most common organ dysfunction in patients with acute respiratory distress syndrome. It may develop as a result of blood gas disturbances that compromise renal blood flow and renal compensatory mechanisms; pulmonary hypertension, which may aggravate renal impairment by causing renal congestion and tissue edema; and mechanical ventilation–induced alterations, including systemic release of mediators, all which promote end-organ cell injury. Acute kidney injury, on the other hand, may initiate and perpetuate lung injury resulting from fluid overload and the systemic release of mediators that promote increased pulmonary vascular permeability, lung inflammation, and apoptosis, and breakdown of the transepithelial electrolyte and water transport, ultimately leading to respiratory failure. It is hoped that an in-depth understanding of the factors influencing lung-kidney interactions will encourage physicians to explore and develop new strategies for the benefit of the patient.

This chapter will:1

Review the pathophysiology of acute lung injury.

2

Summarize the emerging understanding of lung-kidney cross-talk in the critically ill patient.

3

Identify the mechanisms by which acute kidney injury may potentiate acute lung injury.

Pulmonary Artery Systolic Pressure Measured Intraoperatively by Right Heart Catheterization Is a Predictor of Kidney Transplant Recipient Survival

BACKGROUND The effect of pulmonary artery systolic pressure (PASP) measured by Swan-Ganz right heart catheter (SG-RHC) on kidney transplant recipient survival has not been previously studied. The objective of this study was to assess the relationships between PASP measured via SG-RHC, done intraoperatively at the time of initiating anesthesia at the beginning of kidney transplant surgery, and patient survival. Multiple comorbidities, time on dialysis before the transplantation, and graft function were also analyzed in our study. MATERIAL AND METHODS This was a retrospective cohort study using data from all consecutive patients undergoing kidney transplant between January 1, 2005 and December 31, 2009 at Tampa General Hospital. Kidney transplant recipients were divided into 2 groups: Group 1 with PASP <35 mmHg and group 2 with PASP ≥35 mmHg. Patients and graft survival data, time on dialysis before transplant, and comorbidities were compared between the 2 groups. RESULTS Only 363 patients were found to have a documented PASP measurement at the time of anesthesia induction for the transplant surgery, and were included in the specific analysis of our study. Patients with PASP ≥35 mmHg showed a significant decrease in survival in comparison to patients having PASP values <35 mmHg (HR 1.88; 95% CI 1.012 to 3.47, P=0.04). There was a significant positive correlation between time on dialysis and PASP (rho 0.20; 95% CI 0.09 to 0.30, p<0.001), as well as a significant difference in median time on dialysis between PASP <35 vs. PASP ≥35 (22 vs. 29 months, p=0.004). There were no significant differences in graft failure between the 2 PASP groups (HR 0.34; 95% CI 0.12 to 1.01, P=0.05). CONCLUSIONS Patients with PASP ≥35 mmHg, measured intraoperatively by SG-RHC, showed significantly shorter survival in comparison to patients having PASP values <35 mmHg. This result suggests the need for a randomized controlled trial to address the importance of post-transplant pulmonary hypertension management in patient survival.

Cardiopulmonary exercise testing reveals subclinical abnormalities in chronic kidney disease

Background

Reductions in exercise capacity associated with exercise intolerance augment cardiovascular disease risk and predict mortality in chronic kidney disease. This study utilized cardiopulmonary exercise testing to (a) investigate mechanisms of exercise intolerance; (b) unmask subclinical abnormalities that may precede cardiovascular disease in chronic kidney disease.

Design

The design of this study was cross-sectional.

Methods

Cardiopulmonary exercise testing was carried out in 31 Stage 3–4 chronic kidney disease patients (60 ± 11 years; estimated glomerular filtration rate 43 ± 13 ml/min/1.73 m2) and 21 matched healthy individuals (healthy controls; 56 ± 5 years; estimated glomerular filtration rate>90 ml/min/1.73 m2) on a cycle ergometer with workload increased by 15 W every minute until volitional fatigue. Breath-by-breath respiratory gas analysis was performed with an automated gas analyzer and averaged over 10 s intervals.

Results

Peak oxygen uptake was reduced in chronic kidney disease compared to healthy controls (17.43 ± 1.03 vs 28 ± 2.05 ml/kg/min; p < 0.01), as was oxygen uptake at the ventilatory threshold (9.44 ± 0.53 vs15.55 ± 1.34 ml/kg/min; p < 0.01). A steeper minute ventilation rate/carbon dioxide production slope (32 ± 0.8 vs 28 ± 1; p < 0.01) and a lower expired carbon dioxide pressure in chronic kidney disease (27 ± 0.6 vs 31 ± 0.9 vs 0.9; p < 0.01) indicated ventilation perfusion mismatching in these patients. The ventilatory cost of oxygen uptake was higher in chronic kidney disease (37 ± 0.8 vs 33 ± 1; p < 0.01). Maximum heart rate (134 ± 5 vs 159 ± 3 bpm) and one-minute heart rate recovery (15 ± 1 vs 20 ± 2 bpm) were reduced in chronic kidney disease ( p < 0.01).

Conclusion

This study suggests that both central and peripheral limitations likely contribute to reduced exercise capacity in non-dialysis chronic kidney disease. Additionally, cardiopulmonary exercise testing revealed subclinical cardiopulmonary abnormalities in these patients in the absence of overt cardiovascular disease. Cardiopulmonary exercise testing could potentially be a tool for unmasking cardiopulmonary abnormalities preceding cardiovascular disease in chronic kidney disease.

Application of echocardiographic data in patients with chronic kidney disease

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) are at a high risk for cardiovascular events and mortality, particularly heart failure. Echocardiography is the most commonly used diagnostic imaging modality for heart failure. The purpose of this review is to summarize recent literature that demonstrates how echocardiography may be used to define cardiac structure and function in the CKD population and to identify echocardiographic abnormalities that have utility in predicting clinical outcomes in this population.

RECENT FINDINGS

Recent studies have highlighted the high prevalence of echocardiographic abnormalities in this population, and the challenge of identifying specific echocardiographic criteria for heart failure. There have been advances in application of strain echocardiography for evaluating systolic function in patients with normal ejection fraction, understanding pulmonary hypertension and identifying echocardiographic correlates of albuminuria. Additional studies have focused on diastolic dysfunction, left ventricular hypertrophy and echocardiographic findings in children with CKD.

SUMMARY

Recent studies demonstrate the utility of echocardiography in characterizing heart structure and function and in providing potential tools for risk stratification in the high-risk CKD population.

Evolution of Echocardiographic Measures of Cardiac Disease From CKD to ESRD and Risk of All-Cause Mortality: Findings From the CRIC Study

RATIONALE & OBJECTIVE

Abnormal cardiac structure and function are common in chronic kidney disease (CKD) and end-stage renal disease (ESRD) and linked with mortality and heart failure. We examined changes in echocardiographic measures during the transition from CKD to ESRD and their associations with post-ESRD mortality.

STUDY DESIGN

Prospective study.

SETTING & PARTICIPANTS

We studied 417 participants with CKD in the Chronic Renal Insufficiency Cohort (CRIC) who had research echocardiograms during CKD and ESRD.

PREDICTOR

We measured change in left ventricular mass index, left ventricular ejection fraction (LVEF), diastolic relaxation (normal, mildly abnormal, and moderately/severely abnormal), left ventricular end-systolic (LVESV), end-diastolic (LVEDV) volume, and left atrial volume from CKD to ESRD.

OUTCOMES

All-cause mortality after dialysis therapy initiation.

ANALYTICAL APPROACH

Cox proportional hazard models were used to test the association of change in each echocardiographic measure with postdialysis mortality.

RESULTS

Over a mean of 2.9 years between pre- and postdialysis echocardiograms, there was worsening of mean LVEF (52.5% to 48.6%; P<0.001) and LVESV (18.6 to 20.2mL/m^2.7; P<0.001). During this time, there was improvement in left ventricular mass index (60.4 to 58.4g/m^2.7; P=0.005) and diastolic relaxation (11.11% to 4.94% with moderately/severely abnormal; P=0.02). Changes in left atrial volume (4.09 to 4.15mL/m²; P=0.08) or LVEDV (38.6 to 38.4mL/m^2.7; P=0.8) were not significant. Worsening from CKD to ESRD of LVEF (adjusted HR for every 1% decline in LVEF, 1.03; 95% CI, 1.00-1.06) and LVESV (adjusted HR for every 1mL/m^2.7 increase, 1.04; 95% CI, 1.02-1.07) were independently associated with greater risk for postdialysis mortality.

LIMITATIONS

Some missing or technically inadequate echocardiograms.

CONCLUSIONS

In a longitudinal study of patients with CKD who subsequently initiated dialysis therapy, LVEF and LVESV worsened and were significantly associated with greater risk for postdialysis mortality. There may be opportunities for intervention during this transition period to improve outcomes.

Prevalence of pulmonary hypertension in patients with chronic kidney disease without dialysis: a meta-analysis

PURPOSE

Recent epidemiological evidence attempts to demonstrate the risk of pulmonary hypertension (PH) among patients with chronic kidney disease (CKD) without dialysis, but prevalence estimates of PH in CKD without dialysis vary widely in the existing studies. This meta-analysis was to summarize the point prevalence of PH in adults with CKD without dialysis.

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. Associations were tested in subgroups and meta-regression analyses. We also performed sensitivity analyses and assessments of publishing bias.

RESULTS

Twenty-one observational studies (n = 8012 participants) were included in this meta-analysis. The result of analysis in random-effect model showed that the pooled prevalence was 32% (95% CI 23-42%), with significant heterogeneity between these studies (I² = 98%, P < 0.01). Stratified analyses found that the study design, region, sample size, year of publication, and definition of PH based on PASP ≥ 35 mmHg may explain the variation between studies. Sensitivity analysis further demonstrated the results to be robust. There was no evidence of publication bias.

CONCLUSIONS

PH is highly prevalent in patients with CKD without dialysis. Owing to the high heterogeneity, future well-designed and large prospective studies are encouraged to confirm the findings and definitively clarify the potential biological mechanisms.

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.