Risk stratification in patients with pulmonary arterial hypertension at the time of listing for lung transplantation

Prognostic Value of Serial Risk Stratification in Adult and Pediatric Pulmonary Arterial Hypertension: A Systematic Review

BACKGROUND

In pulmonary arterial hypertension, it is recommended to base therapeutic decisions on risk stratification. This systematic review aims to report the prognostic value of serial risk stratification in adult and pediatric pulmonary arterial hypertension and to explore the usability of serial risk stratification as treatment target.

METHODS AND RESULTS

Electronic databases PubMed, Embase, and Web of Science were searched up to January 30, 2023, using terms associated with pulmonary arterial hypertension, pediatric pulmonary hypertension, and risk stratification. Observational studies and clinical trials describing risk stratification at both baseline and follow-up were included. Sixty five studies were eligible for inclusion, including only 2 studies in a pediatric population. C-statistic range at baseline was 0.31 to 0.77 and improved to 0.30 to 0.91 at follow-up. In 53% of patients, risk status changed (42% improved, 12% worsened) over 168 days (interquartile range, 137-327 days; n=22 studies). The average proportion of low-risk patients increased from 18% at baseline to 36% at a median follow-up of 244 days (interquartile range, 140-365 days; n=40 studies). In placebo-controlled drug studies, risk statuses of the intervention groups improved more and worsened less compared with the placebo groups. Furthermore, a low-risk status, but also an improved risk status, at follow-up was associated with a better outcome. Similar results were found in the 2 pediatric studies.

CONCLUSIONS

Follow-up risk stratification has improved prognostic value compared with baseline risk stratification, and change in risk status between baseline and follow-up corresponded to a change in survival. These data support the use of serial risk stratification as treatment target in pulmonary arterial hypertension.

Frequency, characteristics and risk assessment of pulmonary arterial hypertension with a left heart disease phenotype

AIM

To obtain real-world evidence about the features and risk stratification of pulmonary arterial hypertension (PAH) with a left heart disease (LHD) phenotype (PAH-LHD).

METHODS AND RESULTS

By reviewing the records of consecutive incident PAH patients at 7 tertiary centers from 2001 to 2021, we selected 286 subjects with all parameters needed to determine risk of death at baseline and at first follow-up with COMPERA and COMPERA 2.0 scores. Fifty seven (20%) had PAH-LHD according to the AMBITION definition. Compared with no-LHD ones, they were older, had higher BMI, more cardiovascular comorbidities, higher E/e' ratio and left atrial area, but lower BNP concentrations and better right ventricular function and pulmonary hemodynamics. Survival was comparable between PAH-LHD and no-LHD patients, although the former were less commonly treated with dual PAH therapy. Both COMPERA and COMPERA 2.0 discriminated all-cause mortality risk of PAH-LHD at follow-up, but not at baseline. Risk profile significantly improved during follow-up only when assessed by COMPERA 2.0. At multivariable analysis with low-risk status as reference, intermediate-high and high-risk, but not LHD phenotype, were associated with higher hazard of all-cause mortality. Results were comparable in secondary analyses including patients in the last 10 years and atrial fibrillation and echocardiographic abnormalities as additional criteria for PAH-LHD.

CONCLUSIONS

In real life, PAH-LHD patients are frequent, have less severe disease and are less likely treated with PAH drug combinations than no-LHD. The COMPERA 2.0 model may be more appropriate to evaluate their mortality risk during follow-up and how it is modulated by therapy.

Predictors of early mortality after lung transplantation for idiopathic pulmonary arterial hypertension

Lung transplantation remains an important therapeutic option for idiopathic pulmonary arterial hypertension (IPAH), yet short-term survival is the poorest among the major diagnostic categories. We sought to develop a prediction model for 90-day mortality using the United Network for Organ Sharing database for adults with IPAH transplanted between 2005 and 2021. Variables with a p value ≤ 0.1 on univariate testing were included in multivariable analysis to derive the best subset model. The cohort comprised 693 subjects, of whom 71 died (10.2%) within 90 days of transplant. Significant independent predictors of early mortality were: extracorporeal circulatory support and/or mechanical ventilation at transplant (OR: 3; CI: 1.4-5), pulmonary artery diastolic pressure (OR: 1.3 per 10 mmHg; CI: 1.07-1.56), forced expiratory volume in the first second percent predicted (OR: 0.8 per 10%; CI: 0.7-0.94), recipient total bilirubin >2 mg/dL (OR: 3; CI: 1.4-7.2) and ischemic time >6 h (OR: 1.7, CI: 1.01-2.86). The predictive model was able to distinguish 25% of the cohort with a mortality of ≥20% from 49% with a mortality of ≤5%. We conclude that recipient variables associated with increasing severity of pulmonary vascular disease, including pretransplant advanced life support, and prolonged ischemic time are important risk factors for 90-day mortality after lung transplant for IPAH.

Comprehensive Risk Assessment in Patients With Pulmonary Arterial Hypertension Referred for Lung Transplantation

BACKGROUND

Whether comprehensive risk assessment predicts post-referral outcome in patients with pulmonary arterial hypertension (PAH) referred for lung transplantation (LT) in Japan is unknown.Methods and Results: We retrospectively analyzed 52 PAH patients referred for LT. Risk status at referral was assessed using 3- and 4-strata models from the 2022 European Society of Cardiology and European Respiratory Society guidelines. The 3-strata model intermediate-risk group was further divided into 2 groups based on the median proportion of low-risk variables (modified risk assessment [MRA]). The primary outcome was post-referral mortality. During follow-up, 9 patients died and 13 patients underwent LT. There was no survival difference among 3-strata model groups. The 4-strata model classified 33, 16, and 3 patients as low intermediate, high intermediate, and high risk, respectively. The 4-strata model identified high-risk patients with a 1-year survival rate of 33%, but did not discriminate survival between the intermediate-risk groups. The MRA classified 15, 28, 8, and 1 patients as low, low intermediate, high intermediate, and high risk, respectively. High intermediate- or high-risk patients had worse survival (P<0.001), with 1- and 3-year survival rates of 64% and 34%, respectively. MRA high intermediate- or high-risk classification was associated with mortality (hazard ratio 12.780; 95% confidence interval 2.583-63.221; P=0.002).

CONCLUSIONS

Patients classified as high intermediate or high risk by the MRA after treatment should be referred for LT.

Outcomes of listing for lung and heart-lung transplantation in pulmonary hypertension: comparative experience in France and the UK

Background

Lung or heart-lung transplantation (LT/HLT) for severe pulmonary hypertension (PH) as the primary disease indication carries a high risk of waiting list mortality and post-transplant complications. France and the UK both have coordinated PH patient services but with different referral pathways for accessing LT services.

Methods

We conducted a comparative analysis of adult PH patients listed for LT/HLT in the UK and France.

Results

We included 211 PH patients in France (2006-2018) and 170 in the UK (2010-2019). Cumulative incidence of transplant, delisting and waiting list death within 3 years were 81%, 4% and 11% in France versus 58%, 10% and 15% in the UK (p<0.001 for transplant and delisting; p=0.1 for death). Median non-priority waiting time was 45 days in France versus 165 days in the UK (p<0.001). High-priority listing occurred in 54% and 51% of transplanted patients respectively in France and the UK (p=0.8). Factors associated with achieving transplantation related to recipients' height, male sex, clinical severity and priority listing status. 1-year post-transplant survival was 78% in France and 72% in the UK (p= 0.04).

Conclusion

Access to transplantation for PH patients is better in France than in the UK where more patients were delisted due to clinical deterioration because of longer waiting time. High rates of priority listing occurred in both countries. Survival for those achieving transplantation was slightly better in France. Ensuring optimal outcomes after transplant listing for PH patients is challenging and may involve early listing of higher risk patients, increasing donor lung utilisation and improving allocation rules for these specific patients.

Risk Stratification in Pulmonary Arterial Hypertension, Update and Perspectives

Risk stratification in pulmonary arterial hypertension (PAH) is crucial in assessing patient prognosis. It serves a prominent role in everyday patient care and can be determined using several validated risk assessment scores worldwide. The recently published 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines underline the importance of risk stratification not only at baseline but also during follow-up. Achieving a low-risk status has now become the therapeutic goal, emphasising the importance of personalised therapy. The application of these guidelines is also important in determining the timing for lung transplantation referral. In this review, we summarise the most relevant prognostic factors of PAH as well as the parameters used in PAH risk scores and their evolution in the guidelines over the last decade. Finally, we describe the central role that risk stratification plays in the current guidelines not only in European countries but also in Asian countries.

2022 Update of indications and contraindications for lung transplantation in France

Lung transplantation (LTx) is a steadily expanding field. The considerable developments have been driven over the years by indefatigable work conducted at LTx centers to improve donor and recipient selection, combined with multifaceted efforts to overcome challenges raised by the surgical procedure, perioperative care, and long-term medical complications. One consequence has been a pruning away of contraindications over time, which has, in some ways, complicated the patient selection process. The Francophone Pulmonology Society (Société de Pneumology de Langue Française, SPLF) set up a task force to produce up-to-date working guidelines designed to assist pulmonologists in managing end-stage respiratory insufficiency, determining which patients may be eligible for LTx, and appropriately timing LTx-center referral. The task force examined the most recent literature and evaluated the risk factors that limit patient survival after LTx. Ideally, the objectives of LTx are to prolong life while also improving quality of life. The guidelines developed by the task force apply to a limited resource and are consistent with the ethical principles described below.