The Evolution of Pulmonary Artery Denervation for Treatment of Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a progressive, life-limiting disease. Despite significant medical progress over the last three decades, the prognosis of PAH remains poor. PAH is associated with sympathetic nervous system over-stimulation and baroreceptor-mediated vasoconstriction, leading to pathologic pulmonary artery (PA) and right ventricular remodeling. PA denervation is a minimally-invasive intervention that ablates local sympathetic nerve fibers and baroreceptors to modulate pathologic vasoconstriction. Preliminary animal and clinical studies have shown improvements in short-term pulmonary hemodynamics and PA remodeling. However, future studies are needed to elucidate appropriate patient selection, timing of intervention, and long-term efficacy before integration into standard of care.

The ratio of TAPSE to PASP predicts prognosis in lung transplant candidates with pulmonary arterial hypertension.

Lung transplantation (LT) is the only option for patients with pulmonary arterial hypertension (PAH) refractory to maximal medical therapy. However, some patients referred for LT could survive without LT, and its determinants remain unclear. This study aimed to elucidate prognostic factors of severe PAH at the referral time. We retrospectively analyzed 34 patients referred for LT evaluation. The primary outcome was a composite of death or LT. Over a median follow-up period of 2.56 years, eight patients received LT and eight died. Compared with LT-free survival group, pulmonary arterial systolic pressure (PASP) was higher (p = 0.042), and the ratio of tricuspid annular plane systolic excursion (TAPSE) to PASP (TAPSE/PASP) was lower (p = 0.01) in LT or death group. In receiver operating characteristic analysis, the area under the curve was 0.759 (95% confidence interval 0.589-0.929) for TAPSE/PASP to predict primary outcome, and the optimal cut-off value was 0.30 mm/mmHg (sensitivity 0.875 and specificity 0.667). In a multivariate analysis, TAPSE/PASP was independently associated with death or LT. Kaplan-Meier analysis showed a better LT-free survival in patients with TAPSE/PASP ≧0.30 mm/mmHg than in those with < 0.30 mm/mmHg (p = 0.001). Low-level TAPSE/PASP could be a poor prognostic factor in PAH patients referred for LT evaluation.

Treatment effects of pulmonary artery denervation for pulmonary arterial hypertension stratified by REVEAL risk score: Results from PADN-CFDA trial.

BACKGROUND: The differential treatment effect of pulmonary artery denervation (PADN) in pulmonary arterial hypertension (PAH) patients with different risk burdens remains unclear. This study aimed to determine the effectiveness of PADN in low vs intermediate-high-risk PAH patients. METHODS: In total, 128 patients with treatment naive PAH included in the PADN-CFDA trial were categorized into low-risk and intermediate-high-risk patients. The primary endpoint was the between-group difference in the change in 6-min walk distance (6 MWD) from baseline to 6 months. RESULTS: In the intermediate-high-risk group, those treated with PADN and PDE-5i had a greater improvement in 6 MWD from baseline to 6 months as compared to those treated with sham plus PDE-5i. From baseline to 6 months, pulmonary vascular resistance (PVR) was reduced by -6.1 ± 0.6 and -2.0 ± 0.7 Wood units following PADN plus PDE-5i and sham plus PDE-5i, respectively, along with the significant reduction of NT-proBNP in the intermediate-high-risk group. However, there were no significant differences in 6 MWD, PVR, and NT-proBNP between the PADN plus PDE-5i and sham plus PDE-5i groups among low-risk patients. Moreover, the right ventricular function was equally improved by PADN treatment across the low-, intermediate-, and high-risk groups. Clinical worsening was less with PADN plus PDE-5i treatment during the 6-month follow-up. CONCLUSIONS: In patients with pulmonary arterial hypertension, pulmonary artery denervation plus PDE-5i improved exercise capacity, NT-proBNP, hemodynamic, and clinical outcomes during the 6-month follow-up among intermediate-high risk patients.

Portopulmonary hypertension practice patterns after liver transplantation.

Portopulmonary hypertension (POPH) is a type of pulmonary arterial hypertension occurring exclusively in those with portal hypertensive liver disease. Liver transplantation (LT) can significantly improve outcomes. Current guidelines counsel against immediate adjustments to targeted therapy after LT and suggest routine echocardiography as sufficiently informative to guide therapeutic adjustments. Current practice patterns for adjusting targeted therapy after LT in POPH, and how they compare with guidelines, are not well established. To answer this question, we performed an institutional review board-approved, cross-sectional mixed-methods survey-based study of US POPH providers. Anonymized requests to complete the survey were sent through professional networks between January 20, 2022, and April 20, 2022. Responses were compared between cardiologists and pulmonologists using Fisher's exact tests, at a significance of 0.05. A total of 85 POPH physicians were included in the final analysis (66% pulmonologists and 34% cardiologists). Following LT, the majority of respondents routinely used a combination of standard cardiopulmonary assessment modalities to guide adjustment of targeted therapy following LT. Most respondents (69%) started by adjusting parenteral prostacyclins with small titrations and frequent reassessments within 3 months of LT, but some (19.7%) adjusted targeted therapy immediately after LT. Our results showed that the majority of respondents favored serial integrated cardiopulmonary testing (including routine right heart catheterization) to guide the adjustment of targeted therapy in POPH after LT, and almost one-fifth of respondents weaned therapy immediately after LT. Our study demonstrates heterogeneity in POPH practice patterns after LT, highlights differences between current practice patterns and the most recent guidelines, emphasizes the need for additional research, and supports a team-based approach to standardize care for these high-risk patients and optimize post-LT outcomes.

Lung Volume Reduction Surgery Reduces Pulmonary Arterial Hypertension Associated With Severe Lung Emphysema and Hypercapnia.

Lung volume reduction surgery (LVRS) represents a standard surgical approach for patients with severe pulmonary emphysema. One of the relevant risk factors for LVRS is the presence of pulmonary arterial hypertension (PAH). The aim of this study is to assess the postoperative changes in pulmonary arterial pressure (PAP) after LVRS for patients with severe pulmonary emphysema compared with preoperative measures. N = 61 consecutive patients with severe pulmonary emphysema and preoperative evidence for PAH (pulmonary arterial systolic pressure [PASP] ≥ 35 mmHg) were prospectively included into this study. In all patients, thoracoscopic LVRS was performed. PASP was assessed by echocardiography before surgery, early postoperatively, and 3 months after surgery. Data were prospectively recorded and analyzed retrospectively. Primary end points were the postoperative changes in PASP as well as the 90 day mortality rate. Secondary endpoints included: pulmonary function test, exercise capacity, quality of life, and dyspnea symptoms (Borg scale). Early after surgery, a significant reduction in PASP was observed at the day of discharge and at 3 month follow-up. In n = 34 patients, no tricuspid valve regurgitation was detectable anymore suggesting normal PAP. In n = 3 patients, venovenous extracorporeal lung support (VV ECLS) was already implemented preoperatively. In the remaining cases, VV ECLS was applied intraoperatively and continued postoperatively. Mean duration of postoperative ECLS support was 2 days. Four patients died due to acute right heart failure, two patients from sepsis with multiorgan failure, and one patient from acute pulmonary embolism. Ninety day mortality was 11.5 %. A significant improvement was postoperatively observed regarding the performance status, dyspnea scale, as well as quality of life. This study suggests a beneficial effect of LVRS on PAP, which may ultimately help to protect and stabilize right ventricular function. Further studies, implementing pre- and postoperative right heart catheterizations including invasive PAP evaluation, are necessary to support the findings in this study in greater detail.

The Lung Allocation Score Remains Inequitable for Patients with Pulmonary Arterial Hypertension, Even after the 2015 Revision.

Rationale: The lung allocation score (LAS) was revised in 2015 to improve waiting list mortality and rate of transplant for patients with pulmonary arterial hypertension (PAH). Objectives: We sought to determine if the 2015 revision achieved its intended goals. Methods: Using the Standard Transplant Analysis and Research file, we assessed the impact of the 2015 LAS revision by comparing the pre- and postrevision eras. Registrants were divided into the LAS diagnostic categories: group A-chronic obstructive pulmonary disease; group B-pulmonary arterial hypertension; group C-cystic fibrosis; and group D-interstitial lung disease. Competing risk regressions were used to assess the two mutually exclusive competing risks of waiting list death and transplant. Cumulative incidence plots were created to visually inspect risks. Measurements and Main Results: The LAS at organ matching increased by 14.2 points for registrants with PAH after the 2015 LAS revision, the greatest increase among diagnostic categories (other LAS categories: Δ, -0.9 to +2.8 points). Before the revision, registrants with PAH had the highest risk of death and lowest likelihood of transplant. After the 2015 revision, registrants with PAH still had the highest risk of death, now similar to those with interstitial lung disease, and the lowest rate of transplant, now similar to those with chronic obstructive pulmonary disease. Conclusions: Although the 2015 LAS revision improved access to transplant and reduced the risk of waitlist death for patients with PAH, it did not go far enough. Significant differences in waitlist mortality and likelihood of transplant persist.

Pulmonary Artery Denervation for Pulmonary Arterial Hypertension: A Sham-Controlled Randomized PADN-CFDA Trial.

BACKGROUND: World Health Organization (WHO) group 1 pulmonary arterial hypertension (PAH) is a progressive, debilitating disease. Previous observational studies have demonstrated that pulmonary artery denervation (PADN) reduces pulmonary artery pressures in PAH. However, the safety and effectiveness of PADN have not been established in a randomized trial. OBJECTIVES: The aim of this study was to determine the treatment effects of PADN in patients with group 1 PAH. METHODS: Patients with WHO group 1 PAH not taking PAH-specific drugs for at least 30 days were enrolled in a multicenter, sham-controlled, single-blind, randomized trial. Patients were assigned to receive PADN plus a phosphodiesterase-5 inhibitor or a sham procedure plus a phosphodiesterase-5 inhibitor. The primary endpoint was the between-group difference in the change in 6-minute walk distance from baseline to 6 months. RESULTS: Among 128 randomized patients, those treated with PADN compared with sham had a greater improvement in 6-minute walk distance from baseline to 6 months (mean adjusted between-group difference 33.8 m; 95% CI: 16.7-50.9 m; P < 0.001). From baseline to 6 months, pulmonary vascular resistance was reduced by -3.0 ± 0.3 WU after PADN and -1.9 ± 0.3 WU after sham (adjusted difference -1.4; 95% CI: -2.6 to -0.2). PADN also improved right ventricular function, reduced tricuspid regurgitation, and decreased N-terminal pro-brain natriuretic peptide. Clinical worsening was less (1.6% vs 13.8%; OR: 0.11; 95% CI: 0.01-0.87), and a satisfactory clinical response was greater (57.1% vs 32.3%; OR: 2.79; 95% CI: 1.37-5.82) with PADN treatment during 6-month follow-up. CONCLUSIONS: In patients with WHO group 1 PAH, PADN improved exercise capacity, hemodynamic status, and clinical outcomes during 6-month follow-up. (Safety and Efficacy of Pulmonary Artery Denervation in Patients With Pulmonary Arterial Hypertension [PADN-CFDA]; NCT03282266).

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

BACKGROUND: It is unknown whether pulmonary arterial hypertension (PAH) risk stratification instruments could be helpful to support the decision to list a patient for lung transplantation (LT). Our aim was to evaluate contemporary risk assessment tools in a cohort of PAH patients listed for LT. METHODS: Consecutive PAH patients (without pulmonary veno-occlusive disease or unrepaired congenital heart disease) listed for LT at the French Pulmonary Hypertension Reference Center between January 2006 and December 2018 were included. At the time of listing, risk stratification was assessed using the ESC/ERS criteria, the REVEAL Lite 2 score and the COMPERA 2.0 method. The primary end point was overall survival after LT listing. Secondary outcome measures were mortality on waiting list and posttransplant survival. RESULTS: One hundred and two patients were enrolled (mean age 38 ± 13 years, 69% females). Overall survival after listing was 72%, 58% and 46% at 1, 3 and 5 years respectively. Survival after LT listing was lower in "high-risk" patients according to the ESC/ERS criteria (p = 0.0001) and the REVEAL Lite 2 score (p = 0.04). The COMPERA 2.0 method discriminated post-listing survival of patients at high-risk, intermediate-high and intermediate-low risk (p = 0.04). The proportion of patients requiring urgent transplantation and extracorporeal life support as a bridge to transplantation was higher in the "high-risk" patients. Posttransplant survival was significantly lower in "high-risk" patients according to the ESC/ERS criteria (p = 0.0004). CONCLUSIONS: High-risk PAH patients at the time of LT listing have poor outcomes, suggesting that LT should be considered earlier in the course of PAH remaining refractory to triple combination therapy with a parenteral prostacyclin.

Early reduction of pulmonary arterial hypertension in patients using a long-term mechanical ventricular assistance device: a cross-sectional study

ABSTRACT BACKGROUND: Severe pulmonary arterial hypertension (PAH) is a contraindication for heart transplantation (HT). It has been correlated with increased early and late mortality, mainly associated with right ventricular failure. Ventricular assistance devices (VADs) can promote reduction of intracardiac pressures and consequent reduction of PAH over the medium and long terms, thus enabling future candidature for HT. The diminution of early pulmonary pressure within this scenario remains unclear. OBJECTIVE: To evaluate the reduction of PAH and correlate data from right catheterization with the earliness of this reduction. DESIGN AND SETTING: Cross-sectional study in a general hospital in São Paulo, Brazil. METHODS: This was a retrospective analysis on the medical records of patients undergoing VAD implantation in a single hospital. Patients for whom VAD had been indicated as a bridge to candidature for HT due to their condition of constant PAH were selected. RESULTS: Four patients with VADs had constantly severe PAH. Their mean pulmonary artery systolic pressure (PASP) before VAD implantation was 66 mmHg. Over the 30-day period after the procedure, all the patients evolved with a drop in PASP to below 60 mmHg. Their new average was 36 mmHg, which was a drop of close to 50% from baseline values. The one-year survival of this sample was 100%. CONCLUSION: VAD implantation can reduce PAH levels. Early reduction occurred in all patients. Thus, use of VAD is an important bridge tool for enabling candidature for HT among patients with constantly severe PAH.

Early reduction of pulmonary arterial hypertension in patients using a long-term mechanical ventricular assistance device: a cross-sectional study.

BACKGROUND: Severe pulmonary arterial hypertension (PAH) is a contraindication for heart transplantation (HT). It has been correlated with increased early and late mortality, mainly associated with right ventricular failure. Ventricular assistance devices (VADs) can promote reduction of intracardiac pressures and consequent reduction of PAH over the medium and long terms, thus enabling future candidature for HT. The diminution of early pulmonary pressure within this scenario remains unclear. OBJECTIVE: To evaluate the reduction of PAH and correlate data from right catheterization with the earliness of this reduction. DESIGN AND SETTING: Cross-sectional study in a general hospital in São Paulo, Brazil. METHODS: This was a retrospective analysis on the medical records of patients undergoing VAD implantation in a single hospital. Patients for whom VAD had been indicated as a bridge to candidature for HT due to their condition of constant PAH were selected. RESULTS: Four patients with VADs had constantly severe PAH. Their mean pulmonary artery systolic pressure (PASP) before VAD implantation was 66 mmHg. Over the 30-day period after the procedure, all the patients evolved with a drop in PASP to below 60 mmHg. Their new average was 36 mmHg, which was a drop of close to 50% from baseline values. The one-year survival of this sample was 100%. CONCLUSION: VAD implantation can reduce PAH levels. Early reduction occurred in all patients. Thus, use of VAD is an important bridge tool for enabling candidature for HT among patients with constantly severe PAH.

Surgical management of giant pulmonary artery aneurysms in patients with severe pulmonary arterial hypertension.

BACKGROUND AND AIM: Giant aneurysm of the pulmonary artery (PAA) is an extremely rare condition that may develop in patients with pulmonary arterial hypertension (PAH) which may be complicated by rupture, dissection or intravascular thrombus formation. The aim of this study was to examine available literature with regard to surgical strategies in patients undergoing transplantation for PAH with PAA. RESULTS: These patients were traditionally considered for heart-lung transplantation but more recently, there have been reports of successful lung transplantation with reconstruction of the pulmonary artery. CONCLUSIONS: Unless there is a mandatory indication for heart-lung transplantation, patients with PAH and PAA can undergo lung transplantation and reconstruction of the pulmonary artery without compromising the outcome.

Full recovery of right ventricular systolic function in children undergoing bilateral lung transplantation for severe PAH.

BACKGROUND: We investigated whether RV function recovers in children with pulmonary arterial hypertension (PAH) and RV failure undergoing lung transplantation (LuTx). METHODS: Prospective observational study of 15 consecutive children, 1.9 to 17.6 years old, with PAH undergoing bilateral LuTx. We performed advanced echocardiography (Echo) and cardiac magnetic resonance imaging (MRI), followed by conventional and strain analysis, pre- and ∼6 weeks post-LuTx. RESULTS: After LuTx, RV/LV end-systolic diameter ratio (Echo), RV volumes and systolic RV function (RVEF 63 vs 30 %; p < 0.05) by MRI completely normalized, even in children with severe RV failure (RVEF < 40%). The echocardiographic end-systolic LV eccentricity index nearly normalized post-LuTx (1.0 vs 2.0, p < 0.0001) while RV hypertrophy regressed more slowly and was still evident. We found especially the end-systolic RV/LV ratios by Echo (diameter: 0.6 vs 2.6) or MRI (volumes: 0.8 vs 3.4) excellent diagnostic tools (p < 0.05): Together with RVEF by MRI, these ratios were superior to tricuspid annular plane systolic excursion (TAPSE; p = 0.4551) in assessing global systolic RV dysfunction. Moreover, children with severe PAH had reduced RV 2D longitudinal strain (Echo, MRI; p = 0.0450) and decreased RV 2D radial and circumferential strain (MRI; p = 0.0026 and p = 0.0036 respectively), all of which greatly improved following LuTx. CONCLUSION: We demonstrate full recovery of RV systolic function in children within two months after LuTx for severe PAH, independently of the patients' age, weight, and hemodynamic compromise preceding the LuTx. Even in end-stage pediatric PAH with poor RV function and low cardiac output, LuTx should be preferred over heart-lung transplantation.

Plasma metabolomics in the perioperative period of defect repair in patients with pulmonary arterial hypertension associated with congenital heart disease.

The quality of life and survival rates of patients with pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) have been greatly improved by defect-repair surgery and personalized treatments. However, those who survive surgery may remain at risk of persistent PAH, the prognosis may be considerably worse than those unoperated. Dynamic monitoring of clinical measures during the perioperative period of shunt correction is therefore indispensable and of great value. In this study, we explored the plasma-metabolite profiling in 13 patients with CHD-PAH during the perioperative period of defect repair. Plasma was harvested at four time points: prior to cardiopulmonary bypass (CPB) after anesthesia (Pre), immediately after CPB (T0), 24 h (T24), and 48 h (T48) after defect repair. Untargeted metabolomics strategy based on UPLC Q-TOF MS was used to detect the metabolites. A total of 193 distinguishing metabolites were determined at different time points, enriched in pathways such as oxidation of branched-chain fatty acids. We found that 17 metabolite alterations were significantly correlated with the reduction in mean pulmonary arterial pressure (MPAP) at T48 versus Pre. Gradients in diastolic pulmonary arterial pressure (DPAP), bicarbonate in radial artery (aHCO3), bicarbonate in superior vena cava (svcHCO3), and the partial pressure of dissolved CO2 gas in radial artery (aPCO2) were positively correlated with MPAP gradient. Notably, these clinical-measure gradients were correlated with alterations in shunt-correction-associated metabolites. In total, 12 out of 17 identified metabolites in response to defect repair were increased at both T24 and T48 (all P < 0.05, except propionylcarnitine with P < 0.05 at T24). In contrast, galactinol dihydrate, guanosine monophosphate, and hydroxyphenylacetylglycine tended to decline at T24 and T48 (only galactinol dihydrate with P < 0.05 at T48). In conclusion, 17 metabolites that respond to shunt correction could be used as suitable noninvasive markers, and clinical measures, including DPAP, aHCO3, svcHCO3, and aPCO2, would be of great value in disease monitoring and evaluating future therapeutic interventions.

Lung transplantation disparities based on diagnosis for patients bridging to transplant on extracorporeal membrane oxygenation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is increasingly utilized as a bridge to lung transplantation, but ECMO status is not explicitly accounted for in the Lung Allocation Score (LAS). We hypothesized that among waitlist patients on ECMO, patients with pulmonary arterial hypertension (PAH) would have lower transplantation rates. METHODS: Using United Network for Organ Sharing data, we conducted a retrospective cohort study of patients who were ≥12 years old, active on the lung transplant waitlist, and required ECMO support from June 1, 2015 through June 12, 2020. Multivariable competing risk analysis was used to examine waitlist outcomes. RESULTS: 1064 waitlist subjects required ECMO support; 40 (3.8%) had obstructive lung disease (OLD), 97 (9.1%) had PAH,138 (13.0%) had cystic fibrosis (CF), and 789 (74.1%) had interstitial lung disease (ILD). Ultimately, 671 (63.1%) underwent transplant, while 334 (31.4%) died or were delisted. The transplant rate per person-years on the waitlist on ECMO was 15.41 for OLD, 6.05 for PAH, 15.66 for CF, and 15.62 for ILD. Compared to PAH patients, OLD, CF, and ILD patients were 78%, 69%, and 62% more likely to undergo transplant throughout the study period, respectively (adjusted SHRs 1.78 p = 0.007, 1.69 p = 0.002, and 1.62 p = 0.001). The median LAS at waitlist removal for transplantation, death, or delisting were 75.1 for OLD, 79.6 for PAH, 91.0 for CF, and 88.3 for ILD (p < 0.001). CONCLUSIONS: Among patients bridging to transplant on ECMO, patients with PAH had a lower transplantation rate than patients with OLD, CF, and ILD.