Advanced Circulatory Support and Lung Transplantation in Pulmonary Hypertension

The efficacy, safety and clinical feasibility of a percutaneous atrial septal shunt device for pulmonary arterial hypertension: a single-center cohort study

AIM

To evaluate the safety and efficacy of FreeFlow percutaneous atrial septal shunt device (manufactured by AOLIU Medical Technology Co., Ltd, Shanghai, China) in patients with refractory pulmonary arterial hypertension (PAH) for the first time.

METHODS

The study enrolled adult patients diagnosed with refractory pulmonary arterial hypertension (PAH) at the Department of Cardiology, Zhongshan Hospital, Fudan University, between Oct 2021 and Oct 2023. The patients were treated with the FreeFlow percutaneous atrial septal shunt device and underwent follow-up immediately after operation, as well as before and after discharge (at 1, 3, 6, 12 months post-operation). The primary endpoints of the study included the rate of major cardiovascular and cerebrovascular adverse events (MACCEs), serious adverse events (SAEs), and serious device-related adverse events (SADEs) within 12 months of shunt implantation. Data analysis was conducted using SAS 9.3.

RESULTS

A total of 12 patients were enrolled in the study and successfully completed the operation. 10 subjects had completed 12 months' follow-up after operation, while two subjects had died. The incidence of MACCE was 0%, and the incidence of SAEs was 33%, which was unrelated to the treatment with this device. No systemic or instrumental embolizations occurred during the follow-up period. All ten subjects exhibited a stable right-to-left shunt after the operation (100% success rate). Seven patients' New York Heart Association (NYHA) functional classification improved from grade III to grade II. The Short Form-36 (SF-36) score and the 6-minute walking distance (6MWD) at 12 months post-operation were significantly improved compared to baseline, with scores of 47.6 ± 19.5 versus 64.7 ± 24.6 (P = 0.029) and distances of 239.5 ± 137.8 m versus 401.7 ± 129.6 m (P = 0.045), respectively. Similarly, the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and right heart diameter (RAD) also decreased significantly, from 3236 ± 1590.3 pg/mL to 1787.3 ± 703.7 pg/mL (P = 0.039) and from 59.1 ± 10.6 mm to 46.3 ± 7.5 mm (P = 0.046), respectively.

CONCLUSIONS

The results of this clinical study demonstrate that the product can attain the anticipated performance under typical conditions of use. The risks associated with the product are deemed acceptable when weighed against its potential benefits. All preclinical and clinical evaluations have furnished definitive and rational scientific evidence supporting the safety and efficacy of the percutaneous atrial septal shunt.

CLINICAL TRIAL NUMBER

Not applicable.

Lung Transplantation for Pulmonary Arterial Hypertension: Optimized Referral and Listing Based on an Evolving Disease Concept

Pulmonary hypertension (PH) was once a devastating and fatal disease entity, the outlook of which has been significantly improved by the continued progress of medical treatment algorithms. However, some patients still ultimately fail to achieve an adequate clinical response despite receiving maximal medical treatment. Historically, lung transplantation (LTx) has been the only effective therapeutic option that could lead to satisfactory outcomes and save these advanced patients' lives. However, patients with PH tend to have the highest mortality rates on the transplant waiting list; especially after comprehensive medical treatment, they continue to deteriorate very rapidly, eventually missing optimal transplantation windows. Balancing optimized medical treatment with the appropriate timing of referral and listing has been highly controversial in LTx for patients with PH. The 2021 consensus document for the selection of lung transplant candidates from the International Society for Heart and Lung Transplantation (ISHLT) updated the specific recommendations for the LTx referral and listing time for patients with PH based on objective risk stratification. Herein, we review the evolving PH-related concepts and highlight the optimization of LTx referral and listing for patients with PH, as well as their management on the waiting list.

Association of Pulmonary Artery Pressure Change With Post-Lung Transplantation Survival: Retrospective Analysis of China Registry

Background

Extracorporeal membrane oxygenation (ECMO) has been used as intraoperative hemodynamic support in patients with end-stage lung diseases and pulmonary hypertension undergoing lung transplantation (LT).

Objectives

The aim of this study was to identify the association of pulmonary artery pressure change during ECMO and post-LT survival.

Methods

The study investigators collected and analyzed the data from Chinese Lung Transplantation Registry. Patients who have severe pulmonary hypertension with intraoperative ECMO support were enrolled. Post-LT mortality and morbidity were further collected and compared.

Results

A total of 208 recipients were included in the study, during which 53 deaths occurred post-LT. All the patients had severe pulmonary hypertension and were supported by intraoperative ECMO. Using eXtreme Gradient Boosting, or XGboost, model method, 20 variables were selected and ranked. Changes of mean pulmonary artery pressure at the time of ECMO support and ECMO wean-off (ΔmPAP) were related to post-LT survival, after adjusting for potential confounders (recipient age, New York Heart Association functional class status before LT, body mass index, pre-LT hypertension, pre-LT steroids, and pre-LT ECMO bridging). A nonlinear relationship was detected between ΔmPAP and post-LT survival, which had an inflection point of 35 mm Hg. Recipients with ΔmPAP ≦35 mm Hg had higher mortality rate calculated through the Kaplan-Meier estimator (P = 0.041). Interaction analysis showed that recipients admitted in LT center with high case volume (≥50 cases/year) and ΔmPAP >35 mm Hg had better long-term survival. The trend was reversed in recipients who were admitted in LT center with low case volume (<50 cases/year).

Conclusions

The relationship between ΔmPAP and post-LT survival was nonlinear. Optimal perioperative ECMO management strategy with experienced team is further warranted.