The Intersection of Pulmonary Hypertension and Solid Organ Transplantation

Clinical Characteristics and Outcomes Associated With Distinct Hemodynamic Patterns in End-stage Liver Disease: A Retrospective Cohort Analysis

Introduction

Despite advances in the diagnosis and therapeutics strategies for pulmonary hypertension (PH) in patients with end-stage liver disease (ESLD), the impact of hemodynamic patterns among ESLD patients identified through right heart catheterization (RHC) on clinical outcomes remains poorly understood.

Methods

This single-center retrospective cohort study identified patients diagnosed with ESLD who underwent RHC from August 2018 to June 2023. Demographic and clinical data, including comorbidities, transthoracic echocardiography, and RHC findings, were obtained. Our outcomes of interest were all-cause mortality and the chance of receiving orthotopic liver transplantation (OLT) within a year after RHC. Kaplan-Meier with log-rank test was employed to generate survival curves.

Results

We identified 415 ESLD patients with the RHC results. The median (IQR) age was 59 years (52-66), and 62% were male. Caucasians accounted for 43%, followed by African Americans (30%). Up to 89% had a diagnosis of portal hypertension. Median MELD-Na score was 30 (19-36). The etiology of ESLD was mainly from alcohol use (55%). Patients were classified based on RHC results as pre-capillary PH (19%), post-capillary PH (28%), and non-PH (53%) groups. Overall, one-year mortality post-RHC was 22%, with no significant difference in mortality regardless of hemodynamic group. However, the pre-capillary PH group was less likely to receive OLT compared to other groups (P < 0.001).

Conclusion

We observed no difference in all-cause mortality among hemodynamic groups. However, pre-capillary PH group were less likely to undergo OLT compared to others. Further investigations are necessary to determine how this should be addressed in clinical practice.

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.

Outcome of lung transplantation in non-idiopathic pulmonary fibrosis interstitial lung disease

Lung transplantation remains the only curative treatment option for selected patients with end-stage interstitial lung disease (ILD). Candidate selection is impeded by patient heterogeneity, particularly in the subgroup of non-idiopathic pulmonary fibrosis (non-IPF) interstitial lung diseases. We performed a descriptive analysis of all non-IPF ILD patients who underwent lung transplantation in our center between July 1991 and November 2016 (n = 129) and searched for pre-transplant variables correlating with graft loss and chronic lung allograft dysfunction (CLAD). Our study cohort was characterized by a significantly affected medical condition, an extensive pre-transplant corticosteroid use (73.8%), and a high prevalence of pulmonary hypertension (55.7%). Earlier year of transplantation (P = .004), higher bilirubin level (P < .0001), older recipient age (P = .04), and smaller recipient height (P = .02) were found to be associated with earlier graft loss in multivariate analysis. Moreover, pre-transplant corticosteroid treatment tended to be related to earlier graft loss (P = .06), while pulmonary hypertension did not significantly correlate. None of the pre-transplant variables were shown to be associated with CLAD development. Ongoing research is required to further explore this diverse patient population and the pre-transplant variables determining their post-transplant outcome.

Adding value to myocardial perfusion SPECT/CT studies that include coronary calcium CT: Detection of incidental pulmonary arterial dilatation

The aim of the present study was to evaluate the incidence of undiagnosed pulmonary arterial dilatation using the gated computed tomography (CT) images acquired in patients with an otherwise normal Tc-sestamibi single-photon-emission CT (SPECT)/CT myocardial perfusion study.This was a retrospective review of 200 consecutive patients (100 men, mean age 58.7 years) who underwent a myocardial perfusion Tc-sestamibi SPECT/CT study with normal perfusion and with gated CT images acquired for coronary calcium scoring. The CT images were reviewed using a previously validated mean main pulmonary artery diameter (mPAD) measurement method which has been correlated with pulmonary arterial hypertension (PAH). Clinical information on multiple comorbidities was also retrieved. Previously reported mPAD cutoffs (>29.5 and >31.5 mm) were used to stratify patients.Indications for the study included dyspnea on exertion (58.9%), preoperative workup (22.3%), and chest pain (13.9%). The mean mPAD measurement was 26.3 mm (±0.5). There was a significant correlation between body mass index and mPAD (correlation coefficient [ρ]: 0.28; P < .001). About 23% (46/200) of patients had mPAD > 29.5 mm and 15.0% (30/200) of patients had mPAD > 31.5 mm. From previous work, these cutoffs have a sensitivity and specificity for PAH of 70.8%, 79.4% and 52.0%, 90.2%, respectively. Among patients undergoing a preoperative myocardial perfusion study, 35.6% (16/45) patients had mPAD > 29.5 mm and 26.7% (12/45) patients had mPAD > 31.5 mm. There was a higher prevalence of congestive heart failure (62.5% vs 19.6%; P < .001) and hypertension (78.3% vs 21.7%; P < .02) in patients with mPAD > 29.5 mm. Similarly, there was a high prevalence of congestive heart failure (P < .001), hyperlipidemia (P < .04), and hypertension (P < .04) in patients with mPAD > 31.5 mm.Incidental pulmonary arterial dilatation (mPAD ≥ 29.5 mm) can be detected in a large number of patients with normal myocardial perfusion scintigraphy and correlates with multiple different comorbidities. The mPAD can be measured in all patients undergoing gated imaging as part of a myocardial perfusion study, and PAH may be considered as an alternative explanation for symptoms in some patients without perfusion deficits. The data to make this potential diagnosis is already being acquired and represents an opportunity to add value to the interpretations of otherwise negative myocardial perfusion studies.