Pulmonary Hypertension Predicts Adverse Outcomes in Renal Patients: A Systematic Review and Meta‐Analysis

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.

Changes in Cardiac Structure and Function of Recipients after Kidney Transplantation

Background: Chronic kidney disease (CKD) elevates the risk of cardiovascular disease (CVD) and mortality. Uremic cardiomyopathy, frequently observed in CKD and end-stage renal disease (ESRD), involves alterations in cardiac structure and function, which may reverse post-kidney transplantation, although data remain controversial. This study examines the relationship between graft function and changes in cardiac parameters pre- and post-transplantation in kidney transplant recipients. Methods: A total of 145 pediatric and adult recipients of living or deceased donor kidney transplants were enrolled at Gazi Yaşargil Training and Research Hospital. This cohort study utilized transthoracic echocardiographic (TTE) imaging pre-transplant and at least two years post-transplant. Echocardiographic parameters were analyzed using standard techniques. Results: The mean age of the participants was 35 years, with 60% male. The average dialysis duration prior to transplantation was 27 months. Most recipients (83.4%) received kidneys from living donors. Left ventricular diastolic dysfunction increased significantly post-transplant (p < 0.05), while other cardiac dimensions and functions, such as ejection fraction and pulmonary artery pressure, showed no significant change (p > 0.05). Notably, diastolic dysfunction worsened in patients with dysfunctional grafts (GFR < 45), correlating with increased pulmonary artery pressure post-transplant. The rate of antihypertensive drug use and the prevalence of diabetes mellitus increased significantly post-transplant (p < 0.05). Conclusions: This study demonstrates that left ventricular diastolic dysfunction present before kidney transplantation continues to persist post-transplantation in patients with end-stage renal disease undergoing chronic kidney disease treatment. Furthermore, it shows an increased rate of pulmonary artery pressure and pericardial effusion in patients with dysfunctional grafts after transplantation. Further research is required to explore strategies to reverse uremic cardiomyopathy and reduce cardiovascular risk in these patients.

Pulmonary hypertension and chronic kidney disease: prevalence, pathophysiology and outcomes

Pulmonary hypertension (PH) is common in patients with chronic kidney disease (CKD) or kidney failure, with an estimated prevalence of up to 78% in those referred for right-heart catheterization. PH is independently associated with adverse outcomes in CKD, raising the possibility that early detection and appropriate management of PH might improve outcomes in at-risk patients. Among patients with PH, the prevalence of CKD stages 3 and 4 is estimated to be as high as 36%, and CKD is also independently associated with adverse outcomes. However, the complex, heterogenous pathophysiology and clinical profile of CKD-PH requires further characterization. CKD is often associated with elevated left ventricular filling pressure and volume overload, which presumably leads to pulmonary vascular stiffening and post-capillary PH. By contrast, a distinct subgroup of patients at high risk is characterized by elevated pulmonary vascular resistance and right ventricular dysfunction in the absence of pulmonary venous hypertension, which may represent a right-sided cardiorenal syndrome defined in principle by hypervolaemia, salt avidity, low cardiac output and normal left ventricular function. Current understanding of CKD-PH is limited, despite its potentially important ramifications for clinical decision making. In particular, whether PH should be considered when determining the suitability and timing of kidney replacement therapy or kidney transplantation is unclear. More research is urgently needed to address these knowledge gaps and improve the outcomes of patients with or at risk of CKD-PH.

Management and Outcomes of Kidney Transplant Candidates With Severe Pulmonary Hypertension: A Single-center Strategy and Experience

Background

Severe pulmonary hypertension (PH) is associated with high mortality posttransplant and thus is considered a contraindication to kidney transplantation. In this study, we describe the pretransplant management and posttransplant outcomes in patients with severe PH using a multidisciplinary approach.

Methods

Between 11 of 2013 and 8 of 2022, we identified all patients with severe PH on initial pretransplant workup who underwent ultrafiltration (UF) or medical therapy for PH before transplant. Posttransplant we evaluated the perioperative course, renal function, graft, and patient survival. We compared survival to those who remained waitlisted or were delisted.

Results

Three-two patients (mean age = 55.03 ± 10.22 y) diagnosed with severe PH on pretransplant screening echocardiogram. Thirty patients (94%) were subjected to a median of 4 (range, 3-8) UF sessions with an average weight loss of 4.33 ± 2.6 kg. Repeat assessment of PH revealed a decline in mean pulmonary artery systolic pressure from 67 ± 12 mm Hg to 43 ± 13 mm Hg (P < 0.0001). Seventeen patients (53%) received a kidney transplant. The mean estimated Glomerular Filtration Rate at 3, 6, 9, and 12 mo was 72 ± 27, 72 ± 28, 75 ± 29, and 75 ± 29 mL/min/1.73 m2. Among, those who underwent transplantation both graft and patient survival was 100% at 1-y posttransplant. Overall, since the UF intervention, at a median follow-up of 88 ± 12 mo those transplanted had a patient survival of 88% while those who remained on dialysis had a survival of 53% (P = 0.0003).

Conclusion

In this single-center study, we report postcapillary PH can be a significant contributor to elevations in pulmonary artery systolic pressure. Using a multidisciplinary approach, PH can improve with volume removal and phosphodiesterase 5 inhibitors therapy leading to a successful posttransplant outcome.

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.

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.

Pulmonary Arterial Hypertension and Adverse Outcomes after Kidney Transplantation: A Systematic Review and Meta-Analysis

Pulmonary arterial hypertension (PH) has a high prevalence in chronic kidney disease (CKD) patients, especially those undergoing kidney transplantation (KT). We aimed to systematically review and calculate the pooled effect size of the literature evaluating the association between pre-existing PH documented by transthoracic echocardiography (TTE) or invasively and adverse outcomes following KT. The primary composite outcome extracted from the included studies was represented by the mortality from any cause following KT and delayed graft function (DGF), graft dysfunction, or graft failure. The secondary outcomes were represented by individual components of the primary composite outcome. Twelve studies meeting the inclusion criteria were selected. The main finding is that pre-existing PH was associated with increased mortality and a higher rate of DGF, kidney graft dysfunction, or failure in KT recipients. The effect remained significant for all outcomes irrespective of PH evaluation, invasively or using TTE. Consequently, patients with PH defined only by TTE were at higher risk of death, DGF, or graft failure. Our findings support the routine assessment of PH in patients on the KT waitlist. PH might represent an extensively available and valuable tool for risk stratification in KT patients. These data should be confirmed in large prospective clinical trials.

Incidence, Clinical Correlates, and Outcomes of Pulmonary Hypertension After Kidney Transplantation: Analysis of Linked US Registry and Medicare Billing Claims

BACKGROUND

The incidence, risks, and outcomes associated with pulmonary hypertension (P-HTN) in the kidney transplant (KTx) population are not well described.

METHODS

We linked US transplant registry data with Medicare claims (2006-2016) to investigate P-HTN diagnoses among Medicare-insured KTx recipients (N = 35 512) using billing claims. Cox regression was applied to identify independent correlates and outcomes of P-HTN (adjusted hazard ratio [aHR] 95%LCLaHR95%UCL) and to examine P-HTN diagnoses as time-dependent mortality predictors.

RESULTS

Overall, 8.2% of recipients had a diagnostic code for P-HTN within 2 y preceding transplant. By 3 y posttransplant, P-HTN was diagnosed in 10.310.6%11.0 of the study cohort. After adjustment, posttransplant P-HTN was more likely in KTx recipients who were older (age ≥60 versus 18-30 y a HR, 1.912.403.01) or female (aHR, 1.151.241.34), who had pretransplant P-HTN (aHR, 4.384.795.24), coronary artery disease (aHR, 1.051.151.27), valvular heart disease (aHR, 1.221.321.43), peripheral vascular disease (aHR, 1.051.181.33), chronic pulmonary disease (aHR, 1.201.311.43), obstructive sleep apnea (aHR, 1.151.281.43), longer dialysis duration, pretransplant hemodialysis (aHR, 1.171.371.59), or who underwent transplant in the more recent era (2012-2016 versus 2006-2011: aHR, 1.291.391.51). Posttransplant P-HTN was associated with >2.5-fold increased risk of mortality (aHR, 2.572.843.14) and all-cause graft failure (aHR, 2.422.642.88) within 3 y posttransplant. Outcome associations of newly diagnosed posttransplant P-HTN were similar.

CONCLUSIONS

Posttransplant P-HTN is diagnosed in 1 in 10 KTx recipients and is associated with an increased risk of death and graft failure. Future research is needed to refine diagnostic, classification, and management strategies to improve outcomes in KTx recipients who develop P-HTN.

Right Ventricular Dysfunction and Adverse Outcomes after Renal Transplantation

INTRODUCTION

Pulmonary hypertension is common among patients with end-stage renal disease, although data regarding the impact of right ventricular (RV) failure on postoperative outcomes remain limited. We hypothesized that echocardiographic findings of RV dilation and dysfunction are associated with adverse clinical outcomes after renal transplant.

METHODS

A retrospective review of adult renal transplant recipients at a single institution from January 2008 to June 2010 was conducted. Patients with transthoracic echocardiograms (TTEs) within 1 year leading up to transplant were included. The primary end point was a composite of delayed graft function, graft failure, and all-cause mortality.

RESULTS

Eighty patients were included. Mean follow-up time was 9.4 ± 0.8 years. Eight patients (100%) with qualitative RV dysfunction met the primary end point, while 39/65 patients (60.0%) without RV dysfunction met the end point (p = 0.026). Qualitative RV dilation was associated with a significantly shorter time to all-cause graft failure (p = 0.03) and death (p = 0.048). RV systolic pressure was not measurable in 45/80 patients (56%) and was not associated with outcomes in the remaining patients.

CONCLUSION

RV dilation and dysfunction are associated with adverse outcomes after renal transplant. TTE assessment of RV size and function should be a standard part of the pre-kidney transplant cardiovascular risk assessment.

Clinical impact of pre-kidney transplant pulmonary hypertension on post-transplant outcomes

Outcomes of kidney transplant (KT) patients with pre-transplant pulmonary hypertension (PH) are poorly understood. PH patients are often considered high risk and excluded from KT. We investigated the association of pre-transplant PH with KT recipient's outcomes. A single-center, retrospective study that reviewed all patients transplanted from 2010 to 2016, who had a transthoracic echocardiogram (TTE) before KT and at least one TTE post-KT. The TTE closest to the KT was used for analyses. PH is defined as pulmonary artery systolic pressure (PASP) ≥ 40 mm Hg. Of 204 patients, 61 had PASP ≥ 40 mm Hg (with PH) and 143 had PASP < 40 mm Hg (without PH) prior to KT. No statistically significant differences existed between the two groups in baseline demographics, renal failure etiologies, dialysis access type, and cardiovascular risk factors. The mean difference in pre-KT PASP was 18.1 ± 7 mm Hg (P < 0.001). Patients with PH had a statistically significant decrease in PASP post-KT compared to the patients without PH with a mean change of -7.03 ± 12.28 mm Hg vs. + 3.96 ± 11.98 mm Hg (p < 0.001), respectively. Moderate mitral and moderate-severe tricuspid regurgitation were the only factors found to be independently associated with PH (p = 0.001) on multivariable analysis. No statistically significant difference was notable in patient survival, graft function, and creatinine post-KT in both groups. PH pre-KT particularly mild-moderate PH did not adversely affect intermediate (90-day) and long-term allograft and patient survival. Patients with mild-moderate PH should not be excluded from KT.

The Association of Pretransplant Pulmonary Hypertension With Patient and Graft Survival After Kidney Transplantation: A Retrospective Cohort Study

BACKGROUND

Pulmonary hypertension (PH) has been well characterized in end-stage kidney disease and carries a grave prognosis. Its relationship to kidney transplantation outcomes is uncertain. The purpose of the present study was to characterize PH in kidney transplant candidates and to evaluate the relationship of PH to post-transplantation outcomes.

METHODS

A retrospective review of medical records and echocardiographic findings in all patients listed and transplanted at a large urban academic medical center from 2010 to 2015 was undertaken. PH (defined as echocardiographic evidence of pulmonary artery systolic pressure ≥ 35 mm Hg) was assessed along with demographics, and comorbidities for its relationship to patient, and graft survival by univariable and multivariable analysis.

RESULTS

Of 733 patients, 15.6% (115) had PH. PH in this population was primarily due to left ventricular (LV) diastolic dysfunction. Patient survival (78.3% vs 89.6%, P = .02) and the composite of patient and graft survival (70.7% vs 85.0%, P = .04) was reduced at 5 years in patients with PH as compared to patients with No PH, respectively. However, multivariable analysis suggested that age at presentation, race, and left ventricular systolic function but not PH were significantly associated with patient mortality or graft loss.

CONCLUSION

Reduced patient and graft survival seen in patients with pulmonary hypertension appears to be related to risk factors other than the pulmonary hypertension itself; therefore, pretransplant PH should not be considered as a barrier to kidney transplantation.

Comprehensive network analysis to identify the molecular pathogenesis of pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PAH) is a chronic progressive disease that may lead to right heart failure and eventually death. At present, great progress had been achieved in the treatment of pulmonary hypertension. However, pulmonary hypertension cannot be fundamentally cured, and its pathogenesis is still unclear.

METHODS

A multifactor-driven dysfunction module of pulmonary hypertension has been constructed in order to explore its potential pathogenesis. We performed differential expression analysis, coexpression analysis, enrichment analysis and hypergeometric test to calculate the potential regulatory effects of multiple factors on the module.

RESULTS

Four modules and corresponding hub genes were identified. In addition, we also obtained a series of ncRNA (MALAT1 and miR-17-5p) and transcription factor (HIF1A). Network analysis revealed that MALAT1, NFKB1 and RELA targeting IL1B of module 4 and IL6 of module 1 to participate in the occurrence and development of pulmonary hypertension through Toll-like receptor signaling pathway.

CONCLUSIONS

It is necessary to identify disease-related disorders by integrating multiple regulatory factors. The regulatory network may play an important role in PAH. The results not only provided new methods and ideas for follow-up research, but also helps researchers to have a deeper understanding of potential pathogenesis for PAH.