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

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.

Chronic kidney disease and pulmonary hypertension: Progress in diagnosis and treatment

Pulmonary hypertension (PH) is a medical condition characterized by elevated pulmonary vascular resistance and pressure, resulting from different diseases. Due to their high occurrence of PH, intricate hemodynamic classification, and frequently multifactorial cause and mechanism, individuals suffering from chronic kidney disease (CKD) are categorized as the fifth primary group of PH. Based on both domestic and international research, this article provides information on the epidemiology, risk factors, pathogenesis, and targeted drug treatment of PH associated with CKD.

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.

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.

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.

The echocardiographic course of pretransplant pulmonary hypertension following kidney transplantation and associated outcomes

The post 3 kidney transplant course of pretransplant echocardiographically‐defined pulmonary hypertension (PH) was reviewed in 115 patients. Of these 61 patients (the largest cohort reported to date), underwent 160 “for indication” echocardiograms posttransplant (mean echocardiograms per patient: 2.6 ± 2.3). Patients undergoing posttransplant echocardiograms demonstrated greater risks for worse outcomes than those without posttransplant echocardiograms; however, there was no difference in mortality, death‐censored graft failure or the composite of death or graft failure between these two groups. Of patients tested, 36 (59%) showed resolution of PH at a median of 37.5 months. Six patients (16.7%) in whom PH resolved (at a median of 29 months), experienced recurrence of PH after an interval of 48 months. No pretransplant demographic or echocardiographic characteristics distinguished those in whom PH persisted versus resolved. Though there was no difference in the risk for mortality or death‐censored graft loss between the two groups at 3 and 5 years, there was a higher risk for the composite of mortality or graft loss at three but not at five years in the group with persistent PH. In conclusion, echocardiographically defined PH resolved in 59% of patients following kidney transplantation; but irrespective of resolution there was no clear association with worse outcome.

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.