Long-term intravenous epoprostenol infusion in primary pulmonary hypertension: prognostic factors and survival

Long-term efficacies of selective vasodilators in pulmonary arterial hypertension: a comprehensive comparison using a spontaneous reporting database

There is no clinical evidence of differences in drugs associated with long-term survival in patients with pulmonary arterial hypertension (PAH) due to the small population and lack of information on death in Japanese medical database systems. This study evaluated whether patient data from a spontaneous reporting database could be used for comparing the effects of pulmonary vasodilators on long-term survival in PAH patients. PAH patient data reported in the Japanese Adverse Drug Event Report (JADER) database from April 2004 to July 2022 were extracted. Kaplan-Meier curves were used to compare survival times. Adjusted hazard ratios (aHRs) for all-cause mortality were determined using Cox proportional hazards models. Of 1969 PAH patients reported in the JADER database, 1208 were included in the survival analyses. The patient demographics were similar to those of the PAH population reported in the Japan Pulmonary Hypertension Registry. Among drugs targeting the prostacyclin pathway, epoprostenol was most associated with long-term survival (aHR, 0.38; 95% confidence interval (CI), 0.23-0.64). The PAH patients treated with endothelin receptor antagonists had improved survival, especially among the macitentan users (aHR, 0.30; 95% CI, 0.22-0.42). Sildenafil was associated with a poor prognosis in the PAH patients (aHR, 1.56; 95% CI, 1.19-2.04). Although our results must be interpreted with caution due to several limitations inherent to spontaneous reporting databases, our approach using the JADER database for survival analysis may provide useful information in limited situations such as the treatment of rare diseases including PAH.

Younger age at initiation of subcutaneous treprostinil is associated with better response in pediatric Group 1 pulmonary arterial hypertension

Children with severe Group 1 pulmonary arterial hypertension (PAH) have an unpredictable response to subcutaneous treprostinil (TRE) therapy, which may be influenced by age, disease severity, or other unknown variables at time of initiation. In this retrospective single-center cohort study, we hypothesized that younger age at TRE initiation, early hemodynamic response (a decrease in pulmonary vascular resistance by ≥30% at follow-up catheterization), and less severe baseline hemodynamics (Rp:Rs < 1.1) would each be associated with better clinical outcomes. In 40 pediatric patients with Group I PAH aged 17 days-18 years treated with subcutaneous TRE, younger age (cut-off of 6-years of age, AUC 0.824) at TRE initiation was associated with superior 5-year freedom from adverse events (94% vs. 39%, p = 0.002), better WHO functional class (I or II: 88% vs. 39% p = 0.003), and better echocardiographic indices of right ventricular function at most recent follow-up. Neither early hemodynamic response nor less severe baseline hemodynamics were associated with better outcomes. Patients who did not have a significant early hemodynamic response to TRE by first follow-up catheterization were unlikely to show subsequent improvement in PVRi (1/8, 13%). These findings may help clinicians counsel families and guide clinical decision making regarding the timing of advanced therapies.

Contribution of pressure and flow changes to resistance reduction after pulmonary arterial hypertension treatment: a meta-analysis of 3898 patients

Background

Pulmonary arterial hypertension (PAH)-targeted therapies exert significant haemodynamic changes; however, systematic synthesis is currently lacking.

Methods

We searched PubMed, CENTRAL and Web of Science for studies evaluating mean pulmonary artery pressure (mPAP), cardiac index/cardiac output (CI/CO) and pulmonary vascular resistance (PVR) of PAH-targeted therapies either in monotherapy or combinations as assessed by right heart catheterisation in treatment-naïve PAH patients. We performed a random-effects meta-analysis with meta-regression.

Results

We included 68 studies (90 treatment groups) with 3898 patients (age 47.4±13.2 years, 74% women). In studies with small PVR reduction (<4 WU), CI/CO increase (R2=62%) and not mPAP reduction (R2=24%) was decisive for the PVR reduction (p<0.001 and p=0.36, respectively, in the multivariable meta-regression model); however, in studies with large PVR reduction (>4 WU), both CI/CO increase (R2=72%) and mPAP reduction (R2=35%) contributed significantly to the PVR reduction (p<0.001 and p=0.01, respectively). PVR reduction as a percentage of the pre-treatment value was more pronounced in the oral+prostanoid intravenous/subcutaneous combination therapy (mean difference -50.0%, 95% CI -60.8- -39.2%), compared to oral combination therapy (-41.7%, -47.6- -35.8%), prostanoid i.v./s.c. monotherapy (-31.8%, -37.6- -25.9%) and oral monotherapy (-21.6%, -25.4- -17.8%). Changes in haemodynamic parameters were significantly associated with changes in functional capacity of patients with PAH as expressed by the 6-min walking distance.

Conclusion

Combination therapies, especially with the inclusion of parenteral prostanoids, lead to remarkable haemodynamic improvement in treatment-naïve PAH patients and may unmask the contribution of mPAP reduction to the overall PVR reduction in addition to the increase in CO.

A Systematic Review of Novel Therapies of Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive, cureless disease, characterized by increased pulmonary vascular resistance and remodeling, with subsequent ventricular dilatation and failure. New therapeutic targets are being investigated for their potential roles in improving PAH patients' symptoms and reversing pulmonary vascular pathology.

METHOD

We aimed to address the available knowledge from the published randomized controlled trials (RCTs) regarding the role of Rho-kinase (ROCK) inhibitors, bone morphogenetic protein 2 (BMP2) inhibitors, estrogen inhibitors, and AMP-activated protein kinase (AMPK) activators on the PAH evaluation parameters. This systematic review (SR) was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CDR42022340658) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Overall, 5092 records were screened from different database and registries; 8 RCTs that met our inclusion criteria were included. The marked difference in the study designs and the variability of the selected outcome measurement tools among the studies made performing a meta-analysis impossible. However, the main findings of this SR relate to the powerful potential of the AMPK activator and the imminent antidiabetic drug metformin, and the BMP2 inhibitor sotatercept as promising PAH-modifying therapies. There is a need for long-term studies to evaluate the effect of the ROCK inhibitor fasudil and the estrogen aromatase inhibitor anastrozole in PAH patients. The role of tacrolimus in PAH is questionable. The discrepancy in the hemodynamic and clinical parameters necessitates defining cut values to predict improvement. The differences in the PAH etiologies render the judgment of the therapeutic potential of the tested drugs challenging.

CONCLUSION

Metformin and sotatercept appear as promising therapeutic drugs for PAH.

CLINICAL TRIALS REGISTRATION

This work was registered in PROSPERO (CDR42022340658).

Prognostic value of deep echocardiographic phenotyping in pulmonary arterial hypertension

Background

A novel approach to derive prognostic information from echocardiography in pulmonary arterial hypertension (PAH) is to define a phenotype of right heart function combining standard echocardiographic parameters which describe right ventricular pump function and systemic venous congestion. We tested the hypothesis that the combination of advanced strain imaging parameters could yield high prognostic accuracy.

Methods

This was a prospective observational study with a single centre derivation cohort and a second centre validation cohort. The derivation cohort included 49 naive PAH patients who underwent right heart catheterisation and echocardiographic evaluation at baseline and 4-12 months after diagnosis. The validation cohort included 83 prevalent PAH patients who underwent the same examinations at 12 months after diagnosis. We stratified the risk of the derivation cohort according to three models: Model 1, based on haemodynamic parameters; Model 2, based on standard echocardiographic parameters; and Model 3, based on advanced echocardiographic parameters. The median follow-up period was 21 months; the end point of the analysis was clinical worsening.

Results

In the derivation cohort, haemodynamic and echocardiographic parameters obtained at diagnosis were not associated with outcome, whereas a significant association was observed at first reassessment. Model 3 yielded a better predictive accuracy (Harrell's C index 0.832) as compared to Model 2 (Harrell's C index 0.667), and to Model 1 (Harrell's C index 0.713). The validation cohort confirmed the accuracy of Model 3.

Conclusions

A comprehensive assessment of right heart function using right ventricular strain, right atrial reservoir strain and degree of tricuspid regurgitation provides accurate prognostic information in prevalent PAH patients.

Do Patients With Low-Risk Pulmonary Arterial Hypertension Really Benefit From Upfront Combination Therapy?: Insight From the AMBITION Trial

BACKGROUND

Based on results of the Ambrisentan and Tadalafil in Patients with Pulmonary Arterial Hypertension (AMBITION) trial, upfront combination therapy is recommended for treatment-naive patients with low-risk pulmonary arterial hypertension (PAH). However, conflicting data exist whether adopting this treatment strategy in this risk group is beneficial or well tolerated.

RESEARCH QUESTION

Do patients with low-risk PAH really benefit from upfront combination therapy?

STUDY DESIGN AND METHODS

Using the data from the original AMBITION trial, patients with PAH were classified as low, intermediate, or high risk using the Registry to Evaluate Early and Long-term PAH Disease Management 2.0 (REVEAL 2.0) score and the Pulmonary Hypertension Outcomes and Risk Assessment (PHORA) tool. The primary end point was time to clinical worsening (including death, hospitalization for PAH worsening, and disease progression) censored at 1- and 3-year post-enrollment. Side effects that led to withdrawal of treatment were also considered.

RESULTS

Patients with low-risk PAH categorized by REVEAL 2.0 and PHORA did not see a statistically significant benefit of upfront combination therapy vs monotherapy for time to clinical worsening at 1 and 3 years' post-enrollment using Cox proportional analysis (3-year hazard ratio of 0.40 [95% CI, 0.15-1.06; P = .07] and 0.55 [95% CI, 0.26-1.18; P = .12] for REVEAL 2.0 and PHORA, respectively) or considering time to clinical worsening or side effects (3-year hazard ratio of 0.75 [95% CI, 0.39-1.47; P = .4] and 0.87 [95% CI, 0.49-1.54; P = .63] for REVEAL 2.0 and PHORA). Patients with low-risk PAH on upfront combination therapy experienced a higher but not significant incidence of side effects using REVEAL 2.0 and PHORA. In contrast, patients at intermediate or high risk saw a statistically significant benefit of upfront combination therapy considering each of the end points regardless of side effects.

INTERPRETATION

This analysis suggests that perhaps some patients with low-risk PAH should be further stratified using other modalities prior to committing to upfront combination therapy, especially when the occurrence of side effects is considered. Further prospective data are needed to validate this hypothesis prior to changes in current guideline directed therapy are contemplated.

Severity of precapillary pulmonary hypertension: Predictive factor

BACKGROUND AND OBJECTIVES

Patients with pulmonary arterial hypertension (PAH) require risk assessments for prognosis and appropriate therapy. These assessments need to be improved by incorporating clinical and laboratory data such as the analysis of the right ventricle. We aim to establish echocardiographic morphometric data of the right ventricle and its relationship with the left ventricle, to estimate the hemodynamic severity of precapillary pulmonary hypertension (PHprecapillary).

METHODS

This cohort, prospective, observational, and cross-sectional study included 41 consecutive patients with PHprecapillary using echocardiographic study and cardiac catheterization.

RESULTS

Patients' mean age was 44.0±16.4 years, and 37 were women (90.2%). Idiopathic PAH was diagnosed in 18 patients (43.9%). The World Health Organization/New York Association functional class was III or IV in 31 patients (75.6%). The ratio of the right to left ventricles (RV/LV) echocardiographic diastolic diameters was associated with pulmonary arterial pressures in cardiac catheterization, with the best cutoff per receiver operating characteristic curve being 0.8 for systolic pressure (sensitivity 90.0%, specificity 78.3%, area under the curve [AUC] 0.882) and mean pressure (sensitivity 60.0%, specificity 95.7%, AUC 0.823). Spearman's correlation (R) of RV/LV echocardiographic ratio and the hemodynamic variables was significant for systolic pressure (R = 0.7015, p < 0.0001), mean pressure (R = 0.6332, p < 0.0001), transpulmonary pressure gradient (R = 0.6524, p < 0.0001), pulmonary vascular resistance (R = 0.6076, p = 0.0021), and pulmonary vascular resistance index (R = 0.6229, p = 0.0014).

CONCLUSION

The ratio of RV/LV echocardiographic diastolic diameters contribute to the estimates the hemodynamic severity of precapillary pulmonary hypertension. The best cutoff for this assessment was RV/LV of 0.8.

Long-Term Safety, Outcome, and Clinical Effects of Subcutaneous and Intravenous Treprostinil Treatment in Patients with Severe Chronic Pulmonary Arterial Hypertension

BACKGROUND

Current guidelines recommend treatment with parenteral prostacyclin analogs in patients with severe pulmonary arterial hypertension (PAH), who have insufficient response to treatment. Real-life data are sought to help physicians in treatment decisions and clinical care of patients.

OBJECTIVE

This study analyzed safety, clinical effects, and long-term outcomes of subcutaneous (sc) and/or intravenous (iv) treprostinil via different pump systems in consecutive patients with PAH.

METHODS

Thirty-seven patients with severe progressive PAH despite dual combination therapy (20 female, mean age: 52.3 ± 15 years, mean pulmonary vascular resistance: 12.1 ± 5.1 WU) were initiated with add-on treprostinil sc and were routinely clinically assessed. Changes in clinical parameters, adverse events, and outcome were analyzed retrospectively.

RESULTS

In 24 of 37 patients, treprostinil administration was continued iv via implantation of LENUS Pro® pump after 3 ± 1.3 months, 6 patients continued with sc therapy, and 7 discontinued treatment. After 3, 6, 9, and 12 months of treprostinil treatment, patients showed a significant improvement in mean 6-min walk distance and tricuspid annular plane systolic excursion compared to baseline. In 8 of the 24 patients, iv pumps required surgical revision. During a mean follow-up of 2.82 ± 1.95 years, 12 patients died, four received lung transplantation. Transplant-free survival after 1, 2, and 3 years was 85.7%, 69.2%, and 65.3%, respectively.

CONCLUSION

sc treprostinil as add-on to double combination treatment significantly improved exercise capacity and right heart function. In most patients, treprostinil could be continued via more tolerable iv administration approach (LENUS Pro® pump), showing reasonable overall survival with respect to the severity of PAH.

Association Between the Pulmonary Artery Pulsatility Index and Prognosis in Pulmonary Arterial Hypertension: A Multicentre Study

Background

Risk stratification is fundamental in the management of pulmonary arterial hypertension (PAH). Pulmonary artery pulsatility index (PAPi), defined as pulmonary arterial pulse pressure divided by right atrial pressure (RAP), is a hemodynamic index shown to predict acute right ventricular (RV) dysfunction in several settings. Our objective was to test the prognostic utility of PAPi in a diverse multicentre cohort of patients with PAH.

Methods

A multicentre retrospective cohort study of consecutive adult patients with a new diagnosis of PAH on right heart catheterization between January 2016 and December 2020 was undertaken across 4 major centres in Canada. Hemodynamic data, clinical data, and outcomes were collected. The association of PAPi and other hemodynamic variables with mortality was assessed by receiver-operating characteristic curves and Cox proportional hazards modeling.

Results

We identified 590 patients with a mean age of 61.4 ± 15.5 years, with 66.3% being female. A low PAPi (defined as < 5.3) was associated with higher mortality at 1 year: 10.2% vs 5.2% (P = 0.02). In a multivariable model including age, sex, body mass index, and functional class, a low PAPi was associated with mortality at 1 year (area under the curveof 0.64 (95% confidence interval 0.55-0.74). However, high RAP (> 8 mm Hg) was similarly predictive of mortality, with an area under the curve of 0.65.

Conclusion

PAPi was associated with mortality in a large incident PAH cohort. However, the discriminative value of PAPi was not higher than that of RAP alone.

Factors leading to supranormal cardiac index in pediatric pulmonary hypertension patients treated with parenteral prostanoid therapy

Parenteral prostanoid therapy (PPT) can result in supranormal cardiac index (SCI; >4 L/min/m²) in pediatric pulmonary hypertension (PPH) patients. We evaluated the incidence, hemodynamic factors, and outcomes associated with SCI in PPH. This retrospective cohort study included 22 PPH patients on PPT from 2005 to 2020. Hemodynamic profiles were compared between the baseline and 3-6 month follow-up catheterization in the SCI and non-SCI cohorts. Cox regression analysis examined time to composite adverse outcome (CAO; Potts shunt, lung transplant, or death) controlling for initial disease severity. SCI developed in 17 (77%) patients, of whom 11 (65%) developed SCI within 6 months. The SCI cohort was characterized by significant augmentation of cardiac index (CI) and stroke volume (SV) as well as reductions in systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR). Conversely, the non-SCI cohort had unchanged SV despite a modest rise in CI as well as persistent vasoconstriction. After median follow-up of 4.3 years (range 0.2-13 years), non-SCI patients were at significantly increased risk for the CAO (5/5: three deaths, two Potts shunts) compared with SCI patients (5/17: two deaths, three lung transplants; adjusted hazard ratio 14.0 [95% confidence interval: 2.1-91.3], p < 0.001). A majority of PPH patients developed SCI within 6-12 months of starting PPT and demonstrated lower risk of adverse outcomes compared with non-SCI patients. These data suggest that change in SVR and SV after 3-6 months of PPT may be early markers of therapeutic response and prognosis.

Medical Management of Pulmonary Arterial Hypertension: Current Approaches and Investigational Drugs

Pulmonary arterial hypertension (PAH) is a malignant pulmonary vascular syndrome characterized by a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure, which eventually leads to right heart failure and even death. Although the exact mechanism of PAH is not fully understood, pulmonary vasoconstriction, vascular remodeling, immune and inflammatory responses, and thrombosis are thought to be involved in the development and progression of PAH. In the era of non-targeted agents, PAH had a very dismal prognosis with a median survival time of only 2.8 years. With the deep understanding of the pathophysiological mechanism of PAH as well as advances in drug research, PAH-specific therapeutic drugs have developed rapidly in the past 30 years, but they primarily focus on the three classical signaling pathways, namely the endothelin pathway, nitric oxide pathway, and prostacyclin pathway. These drugs dramatically improved pulmonary hemodynamics, cardiac function, exercise tolerance, quality of life, and prognosis in PAH patients, but could only reduce pulmonary arterial pressure and right ventricular afterload to a limited extent. Current targeted agents delay the progression of PAH but cannot fundamentally reverse pulmonary vascular remodeling. Through unremitting efforts, new therapeutic drugs such as sotatercept have emerged, injecting new vitality into this field. This review comprehensively summarizes the general treatments for PAH, including inotropes and vasopressors, diuretics, anticoagulants, general vasodilators, and anemia management. Additionally, this review elaborates the pharmacological properties and recent research progress of twelve specific drugs targeting three classical signaling pathways, as well as dual-, sequential triple-, and initial triple-therapy strategies based on the aforementioned targeted agents. More crucially, the search for novel therapeutic targets for PAH has never stopped, with great progress in recent years, and this review outlines the potential PAH therapeutic agents currently in the exploratory stage to provide new directions for the treatment of PAH and improve the long-term prognosis of PAH patients.

Incidence of Bloodstream Infection in Patients with Pulmonary Hypertension under Intravenous Epoprostenol or Iloprost—A Multicentre, Retrospective Study

Intravenous synthetic prostacyclin analogs (iPCAs), such as epoprostenol, treprostinil and iloprost have been widely used for the treatment of pulmonary arterial hypertension (PAH). Despite having good outcomes, continuous infusion of iPCAs has been associated with some adverse effects. Bloodstream infection (BSI) is one of the most severe complications, although poorly recognized, especially under iloprost administration, which few studies have addressed. This study aimed to compare the BSI incidence rates between intravenous iloprost and epoprostenol administration. Patients with pulmonary hypertension (PH) functional class III or IV receiving intravenous iloprost or epoprostenol through Hickman catheter, between 2004 and 2019, were retrospectively selected from two PH treatment centers. From a total of 36 patients (13 for iloprost and 23 for epoprostenol), 75% (n = 27) fulfilled the PAH criteria, mainly belonging to the idiopathic group. Overall BSI rate was 1.5/1000 days of treatment (3.38 and 0.09/1000 days for iloprost and epoprostenol, respectively). Patients receiving iloprost were at a higher risk of developing BSI than those receiving epoprostenol (HR: 12.5; 95% CI: 1.569–99.092). A higher mortality rate from BSI was also identified in the iloprost group (p = 0.04). Twenty-seven patients developed BSI, with 92% of them requiring hospitalization. A total of 29 agents were found, 10 Gram-positive (mainly Staphylococcus aureus; n = 5) and 19 Gram-negative (mainly Pseudomonas aeruginosa; n = 6) bacteria. Iloprost administration was linked to a significantly higher incidence of BSI, worse prognosis, and more BSI-related deaths than epoprostenol. BSI due to Gram-negative, commensal, low-virulence bacteria was also higher in the iloprost group. In short, physicians should be aware when prescribing iPCA to guarantee their patients’ safety and best medical care.

Right Ventricular Energy Failure Predicts Mortality in Patients With Pulmonary Hypertension

Right ventricular (RV) failure has a significant adverse impact on pulmonary hypertension (PH) prognosis. None of the currently used parameters directly assess whether RV fails to provide enough energy output to propel the blood through diseased pulmonary vascular system. Furthermore, most of the current parameters are affected by the volume status of the patient. We aimed to explore whether RV energy failure has a predictive power for mortality on top of the established prognostic risk parameters in patients with PH. We screened 723 cases from our database. A total of 3 sets of binary regression analyses were executed to determine the hazard ratios (HRs) of RV energy failure for 5-year mortality in clinical, echocardiographic, and hemodynamic context, using adjustment variables chosen according to previous studies. The final study population encompassed 549 cases. A total of 77 patients died during the 5-year follow-up (14%). RV energy failure was observed in 146 of 549 patients (26.6%). In the univariate model, RV energy failure strongly associated with increased long-term mortality (HR 4.25, 95% confidence interval [CI] 2.58 to 7.00, p <0.001). It also emerged as a significant predictor of long-term mortality in clinical and hemodynamic multivariate models (HR 2.59, 95% CI 1.43 to 4.67, p = 0.002 and HR 2.05, 95% CI 1.15 to 3.63, p = 0.015, respectively). In conclusion, our study indicates that the presence of RV energy failure independently predicts long-term mortality in PH.

Acute Vasoreactivity Testing and Outcomes in Pulmonary Arterial Hypertension: A Call for Increased Testing

BACKGROUND

Pulmonary arterial hypertension (PAH) has a progressive, unremitting clinical course. Vasoreactivity testing (VdT) during right heart catheterisation (RHC) identifies a subgroup with excellent long-term response to calcium channel blockade (CCB). Reporting on these patients is limited. Established in 2011, the Pulmonary Hypertension Society of Australia and New Zealand (PHSANZ) registry offers the opportunity to assess the frequency of VdT during RHC, treatment and follow up of PAH patients.

METHODS

Registry data from 3,972 PAH patients with index RHC revealed 1,194 VdT appropriate patients. Data was analysed in three groups: 1) VdT+CCB+: VdT positive, CCB treated; 2) VdT+CCB-: VdT positive, no CCB prescribed, 3) VdT-/noVdT: VdT negative, or VdT not tested. Data was reviewed for adherence to guidelines, clinical response (World Health Organization functional class [WHO FC], 6-minute-walk-distance [6MWD], RHC), and outcomes (survival or lung transplantation).

RESULTS

Patients included had idiopathic (IPAH=1,087), heritable (HPAH=67) and drug or toxin-induced PAH (DPAH=40). A VdT was performed in 22% (268/1,194), with incomplete data in 26% (70/268); 28% (55/198) were VdT+. Analysis group allocation was: VdT+CCB+ (33/55), VdT+CCB- (22/55), VdT- (143)/noVdT (996). From patients with 1-year data VdT+CCB+ and VdT-/noVdT patients improved WHO FC, 6MWD and cardiac index (CI); VdT+CCB- data remained similar. Within the VdT+CCB+ group, 30% (10/33) were long-term CCB responders with a 100% 5-year survival; non-responders had a 61% survival at 5.4 years. Long-term responders were younger at diagnosis (40 yrs vs 54 yrs).

CONCLUSION

Use of VdT testing and documentation is poor in this contemporary patient cohort. Nonetheless, survival in VdT+CCB+ patients from the PHSANZ registry is excellent, supporting guidelines promoting VdT testing. Strategies to promote the use of VdT are warranted.

Risk Stratification and Outcomes in Patients With Pulmonary Hypertension: Insights into Right Ventricular Strain by MRI Feature tracking

BACKGROUND

Despite a recommended multidimensional approach for pulmonary hypertension (PH) risk stratification and guidance of treatment decisions, this may not always be achievable in patients with advanced disease. One issue is the lack of an imaging modality to assess right ventricular (RV) structure and function abnormalities.

PURPOSE

To explore the risk stratification and prognostic value of cardiac MR feature tracking (MR-FT)-derived RV strain.

STUDY TYPE

Retrospective.

POPULATION

A total of 80 patients with idiopathic pulmonary artery hypertension (N = 52) or chronic thromboembolic PH (N = 28).

FIELD STRENGTH

A 1.5 T or 3.0 T, balanced steady-state free precession sequence.

ASSESSMENT

All patients underwent laboratory testing, right heart catheterization, and MR imaging (and in 37 cases, a cardiopulmonary exercise test was also performed) within a 1-month period. Cardiac functional parameters and both global longitudinal strain (GLS) and global circumferential strain (GCS) were analyzed. Patients were stratified into low, intermediate, and high-risk groups by guideline suggested stratified values of risk factors. The combined endpoint was death or hospitalization for congestive heart failure assessed during follow-up since the date of MR examination.

STATISTICAL TESTS

Kolmogorov-Smirnov's test, independent-sample t-tests, Wilcoxon's rank-sum tests, one-way analysis of variance, χ² tests or Fisher's exact test, receiver operating characteristic analysis, Kaplan-Meier survival analysis, and Cox regression analysis. A P value < 0.05 was considered statistically significant.

RESULTS

The median follow-up duration was 3.4 years. Thirty-five patients presented with combined endpoint including 10 cardiac deaths. RV structural and deformation impairments were significantly associated with combined endpoint (ejection fraction: 31.3% ± 13.2% vs. 38.0% ± 14.8%, hazard ratio [HR: 0.974; GLS: -14.5 [-18.6, -10.9] % vs. -20.4 [-26.0, -13.2] %, HR: 1.071; GCS: -9.8 [-14.5, -7.3] % vs. -12.3 [-19.9, -8.4] %, HR: 1.059). There were significant differences in RVGLS among low, intermediate, and high-risk groups (-19.3% ± 7.2% vs. -17.3% ± 9.4% vs. -11.5% ± 4.4% by cardiac functional class, -21.8% ± 7.3% vs. -19.4% ± 8.2% vs. -12.7 ± 5.3% by NT-proBNP, -19.7% ± 7.7 vs. -15.8% ± 6.5% vs. -12.6% ± 8.2% by cardiac index).

DATA CONCLUSION

RV deformation may aid risk stratification in patients with PH, providing crucial information for RV remodeling, pulmonary hemodynamic condition and exercise capacity.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Low Pulmonary Artery Pulsatility Index by Echocardiography Is Associated With Increased Mortality in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a progressive pulmonary vascular disorder with elevated mortality risk. The pulmonary artery (PA) pulsatility index (PAPi) based on invasively acquired parameters has emerged as a hemodynamic risk predictor. Whether noninvasively derived PAPi (PA pulse pressure divided by right atrial pressure) is valuable is unclear.

METHODS

Consecutive patients undergoing transthoracic echocardiography for known or suspected PH were included with conventional echocardiographic measures of PA systolic, PA diastolic, and estimated right atrial pressures. In those patients with PH (mean PA pressure > 20 mm Hg), PAPi was divided into 3 groups: <1.5, 1.5 to 3, and >3. Mortality was assessed over 5 years.

RESULTS

Of 1,045 patients enrolled, 64% had PH. Patients with the lowest PAPi had higher N-terminal-pro hormone B-type natriuretic peptide levels, larger right ventricles (RVs), worse RV systolic function, and greater degrees of tricuspid regurgitation. In patients with PH, PAPi was inversely proportional to the risk of death, with PAPi <3 associated with a 1.96-fold increased risk of death (95% CI, 1.45-2.64, P < .0001). At multivariate analysis, RV longitudinal systolic strain (hazard ratio [HR] = 1.45, 1.24-1.71; P < .0001), PAPi <3 (HR = 1.76, 1.31-2.37; P = .0002), and the presence of a pericardial effusion (HR = 1.64, 1.20-2.26 P = .003) were independently associated with increased mortality. In age- and sex-adjusted models, PAPi was incremental to PA compliance.

CONCLUSIONS

In patients with PH, low PAPi derived noninvasively by transthoracic echocardiography is associated with markers of right heart failure, RV dysfunction, and worse survival. PAPi could be incorporated into the conventional echo parameters reported in patients with PH and may be a useful predictor of outcome.

The Evolving Management and Treatment Options for Patients with Pulmonary Hypertension: Current Evidence and Challenges

Pulmonary hypertension may develop as a disease process specific to pulmonary arteries with no identifiable cause or may occur in relation to other cardiopulmonary and systemic illnesses. The World Health Organization (WHO) classifies pulmonary hypertensive diseases on the basis of primary mechanisms causing increased pulmonary vascular resistance. Effective management of pulmonary hypertension begins with accurately diagnosing and classifying the disease in order to determine appropriate treatment. Pulmonary arterial hypertension (PAH) is a particularly challenging form of pulmonary hypertension as it involves a progressive, hyperproliferative arterial process that leads to right heart failure and death if untreated. Over the last two decades, our understanding of the pathobiology and genetics behind PAH has evolved and led to the development of several targeted disease modifiers that ameliorate hemodynamics and quality of life. Effective risk management strategies and more aggressive treatment protocols have also allowed better outcomes for patients with PAH. For those patients who experience progressive PAH with medical therapy, lung transplantation remains a life-saving option. More recent work has been directed at developing effective treatment strategies for other forms of pulmonary hypertension, such as chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary hypertension due to other lung or heart diseases. The discovery of new disease pathways and modifiers affecting the pulmonary circulation is an ongoing area of intense investigation.

Bedside Ultrasound for Hemodynamic Monitoring in Cardiac Intensive Care Unit

Thanks to the advances in medical therapy and assist devices, the management of patients hospitalized in cardiac intensive care unit (CICU) is becoming increasingly challenging. In fact, Patients in the cardiac intensive care unit are frequently characterized by dynamic and variable diseases, which may evolve into several clinical phenotypes based on underlying etiology and its complexity. Therefore, the use of noninvasive tools in order to provide a personalized approach to these patients, according to their phenotype, may help to optimize the therapeutic strategies towards the underlying etiology. Echocardiography is the most reliable and feasible bedside method to assess cardiac function repeatedly, assisting clinicians not only in characterizing hemodynamic disorders, but also in helping to guide interventions and monitor response to therapies. Beyond basic echocardiographic parameters, its application has been expanded with the introduction of new tools such as lung ultrasound (LUS), the Venous Excess UltraSound (VexUS) grading system, and the assessment of pulmonary hypertension, which is fundamental to guide oxygen therapy. The aim of this review is to provide an overview on the current knowledge about the pathophysiology and echocardiographic evaluation of perfusion and congestion in patients in CICU, and to provide practical indications for the use of echocardiography across clinical phenotypes and new applications in CICU.

The evolving landscape of pulmonary arterial hypertension clinical trials

Although it is a rare disease, the number of available therapeutic options for treating pulmonary arterial hypertension has increased since the late 1990s, with multiple drugs developed that are shown to be effective in phase 3 randomised controlled trials. Despite considerable advancements in pulmonary arterial hypertension treatment, prognosis remains poor. Existing therapies target pulmonary endothelial dysfunction with vasodilation and anti-proliferative effects. Novel therapies that target proliferative vascular remodelling and affect important outcomes are urgently needed. There is need for additional innovations in clinical trial design so that all emerging candidate therapies can be rigorously studied. Pulmonary arterial hypertension trial design has shifted from short-term submaximal exercise capacity as a primary endpoint, to larger clinical event-driven trial outcomes. Event-driven pulmonary arterial hypertension trials could face feasibility and efficiency issues in the future because increasing sample sizes and longer follow-up durations are needed, which would be problematic in such a rare disease. Enrichment strategies, innovative and alternative trial designs, and novel trial endpoints are potential solutions that could improve the efficiency of future pulmonary arterial hypertension trials while maintaining robustness and clinically meaningful evidence.

Evaluation of physical health status beyond daily step count using a wearable activity sensor

Physical health status defines an individual's ability to perform normal activities of daily living and is usually assessed in clinical settings by questionnaires and/or by validated tests, e.g. timed walk tests. These measurements have relatively low information content and are usually limited in frequency. Wearable sensors, such as activity monitors, enable remote measurement of parameters associated with physical activity but have not been widely explored beyond measurement of daily step count. Here we report on results from a cohort of 22 individuals with Pulmonary Arterial Hypertension (PAH) who were provided with a Fitbit activity monitor (Fitbit Charge HR^®) between two clinic visits (18.4 ± 12.2 weeks). At each clinical visit, a maximum of 26 measurements were recorded (19 categorical and 7 continuous). From analysis of the minute-to-minute step rate and heart rate we derive several metrics associated with physical activity and cardiovascular function. These metrics are used to identify subgroups within the cohort and to compare to clinical parameters. Several Fitbit metrics are strongly correlated to continuous clinical parameters. Using a thresholding approach, we show that many Fitbit metrics result in statistically significant differences in clinical parameters between subgroups, including those associated with physical status, cardiovascular function, pulmonary function, as well as biomarkers from blood tests. These results highlight the fact that daily step count is only one of many metrics that can be derived from activity monitors.

Recent Advances in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease in which stenosis or obstruction of the pulmonary arteries (PAs) causes an increase in PA pressure, leading to right-sided heart failure and death. Basic research has revealed a decrease in the levels of endogenous vasodilators, such as prostacyclin, and an increase in the levels of endogenous vasoconstrictors, such as endothelin, in patients with PAH, leading to the development of therapeutic agents. Currently, therapeutic agents for PAH target three pathways that are selective for PAs: the prostacyclin, endothelin, and nitric oxide pathways. These treatments improve the prognosis of PAH patients. In this review, we introduce new drug therapies and provide an overview of the current therapeutic agents.

Therapeutic Use of an Inhaled Drug Delivery in Pulmonary Hypertension: A Review

Pulmonary arterial hypertension (PAH) is a serious condition in which there is increased blood pressure in arteries of the lungs (pulmonary arteries). The therapies or drugs for PAH have expanded with the revelation of three key pathological processes - encompassing prostacyclin, nitric oxide (NO), and endothelin pathways. An outlook for patients suffering from PAH is still mediocre amidst recent advancements. The evolution of pre-clinical and clinical research on PAH has facilitated the identification of several new targeted therapies for the disease. In this article, we examine recent data on new pulmonary hypertension physiological pathways, primarily concentrating on administering drugs through the inhalation route and their effects. Although they have been given clinical use approval, medications based on these routes are presently being studied in clinical or pre-clinical settings. To confirm these innovative medicines' therapeutic efficacy and safety, extensive clinical trials are needed.

Pulmonary Hypertension in Scleroderma- Evaluation and Management

Pulmonary Arterial Hypertension (PAH) is a clinical syndrome consisting of physiologic/hemodynamic criteria that are a consequence of several etiologies. Systemic Sclerosis (SSc), one of the most common causes of PAH, is an autoimmune disorder of the connective tissue leading to fibrosis that involves the skin, gastrointestinal tract, lungs, heart, kidney etc. SSc has an annual prevalence of one to five cases for every 1000 individuals and nearly 15 percent of all cases develop PAH. At its core, Pulmonary hypertension (PH) in SSc is an obliterative vasculopathy in small to medium-sized pulmonary arterioles. A host of other local and systemic mechanisms operate in concert to gradually alter the hemodynamics resulting in elevated pulmonary vascular resistance and thus right ventricular afterload. A diagnosis of PAH in SSc is virtually a death sentence, with studies reporting a mortality rate of 50 per cent in the 3 years of diagnosis. Therefore, developing and implementing a robust screening and diagnosis protocol is crucial in the fight against this pervasive disease. This review aims to summarize the current literature of PAH in SSc, with a special focus on the screening and diagnosis protocols, newer treatment options and prognostic indicators for the same.

Efficacy and safety of sequential combination therapy for pulmonary arterial hypertension: A meta-analysis of Randomized-Controlled Trials

BACKGROUND

Previous meta-analyses of pulmonary arterial hypertension (PAH) combination therapy pooled sequential and initial combination together, which might threaten their authenticity and clinical significance for the difference between two strategies.

METHODS

PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) that compared sequential combination therapy (SCT) with background therapy (BT) in PAH patients. Raw data were extracted to calculate risk ratio (RR) or weighted mean difference (WMD) for predefined efficacy and safety outcomes. Mantel-Haenszel fixed or random effects model was used based on heterogeneity.

RESULTS

17 RCTs involving 4343 patients (97.2% of patients with WHO-FC II-III) were included. SCT decreased clinical worsening (RR 0.66, 95% CI 0.58 to 0.76), nonfatal clinical worsening (RR 0.61, 95% CI 0.52 to 0.71), functional class (decrease of 28% in the portion of patients with WHO-FC worsening and increase of 33% in the portion of patients with WHO-FC improvement), and increased 6-min walk distance (WMD 17.68 m, 95% CI 10.16 to 25.20), but didn't reduce mortality, lung transplantation, admission to hospital, and treatment escalation compared with BT. Although any adverse event and serious adverse event were similar between SCT and BT, SCT increased all-cause treatment discontinuation (RR 1.49, 95% CI 1.30 to 1.71) and drug-related treatment discontinuation (RR 2.30, 95% CI 1.86 to 2.84) with higher incidence of headache, flushing, nausea, diarrhoea and jaw pain.

CONCLUSIONS

For WHO-FC II-III PAH patients who have established BT, our study reinforced the recommendation of SCT to improve clinical worsening, functional status, and exercise capacity, although with higher incidence of side-effects and withdrawal.

Dynamics of 6-Minute Walk Distance as a Predictor of Efficiency Specific Pulmonary Vasodilators

Pulmonary hypertension is a severe and often rapidly progressive disease with a fatal outcome. Approved specific therapy with five classes of drugs – prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, soluble guanylate cyclase stimulators and prostacyclin receptor agonists has significantly improved the prognosis of patients. An accessible and reproducible criterion of exercise tolerance – a distance walked in six-minute walk test (6MXD) – occupies one of the central places among the performance indicators (clinical, echocardiographic and hemodynamic) of specific pulmonary vasodilators. Reflecting the clinical severity of pulmonary hypertension and, according to some data, its long-term prognosis, the dynamics of 6MXD is an integral component of the combined primary endpoints of randomized controlled trials. In the CHEST-2019 recommendations, the dynamics of the 6MXD was used to standardize the randomized controlled trials. The 6MXD is indispensable for dynamic observation and decisionmaking on further treatment tactics 

Mortality risk factors in patients on waiting list for lung transplantation between 2005 and 2018: A single institutional experience

BACKGROUND

Lung transplantation is a therapeutic option for patients with end-stage lung disease. However, the increase in organ demand has surpassed the number of donors, with many patients unable to outlive the long waiting period. This study aimed to assess mortality and its risk factors in patients on the waiting list for lung transplantation in a single medical centre.

METHODS

All evaluated clinical and laboratory data of the patients with end-stage lung disease assessed for lung transplantation between February 2005 and November 2018 in National Taiwan University Hospital were recorded in the waiting list database. The patients in this study were divided into two groups: survival and death groups.

RESULTS

Between February 2005 and November 2018, 169 patients were enrolled in the waiting list. Thirty-one patients were alive and waiting for the chance of lung transplantation, 56 underwent lung transplantation, and 82 died while waiting. The mean age of all patients was 43.7 years, and 91 were women. The mean body mass index (BMI) was 20.3. The most common blood type was type O. All patients were in New York Heart Association (NYHA) class III or IV. After analysis of the two groups, lower BMI presented as a mortality factor.

CONCLUSION

This is the first Taiwanese study to describe the mortality factors in patients waiting for lung transplantation. The main factors influencing the survival of these patients were lower BMI, NYHA class IV, and diseases which cause end-stage lung diseases (infection and pulmonary fibrosis).

Simulation of Acute Pulmonary Hypertension in Beagle Dogs

Acoustic cardiography (AC) combined with heart sound (HS) recording and electrocardiogram (ECG) provides a noninvasive and inexpensive way to understand the electrical mechanical activity of the heart. Pulmonary artery stenosis can cause hemodynamic abnormalities that might lead to pulmonary hypertension (PH). In this paper, we examined the relationships between the acoustic characteristics of the AC and hemodynamic changes in a beagle dog model of PH.Four healthy beagle dogs were injected with the prostaglandin endoperoxide receptor agonist U-44069 to induce acute PH states. AC was employed to analyze the process of pre-PH, intra-PH, and post-PH. Right ventricular blood pressure (RVBP) was measured via right cardiac catheterization, an invasive method performed in parallel for comparative hemodynamic evaluation. As RVBP increased or decreased, the HS features changed accordingly during acute PH occurrence and development. Right ventricular systolic blood pressure (RVSBP) significantly correlated with the minimum of the first HS (S1) amplitude (correlation coefficient (CC) = -0.82), energy of the S1 (CC = 0.86), energy of the second HS (S2) (CC = 0.67), entropy of the S1 (CC = -0.94), and ratio of electromechanical systolic time (EMST) to the cardiac cycle time (CC = 0.81). The two techniques (AC [HSs and ECG] versus right cardiac catheterization [RVBP]) were significantly correlated. Especially, the diastolic filling time (DFT) had a significant relationship with the right ventricular diastolic time (RVDT) (CC = 0.97), perfusion time (PT) (CC = 0.96), and cardiac cycle time (RR) (CC = 0.96). The CCs between the RVDT and the max dp/dt to min dp/dt, the EMST and the Q to min dp/dt, and the electromechanical activation time and the Q to max dp/dt were 0.95, 0.99, and 0.86, respectively. Furthermore, the logistic regression model with different combinations was used to identify the effective features for monitoring hemodynamic and pathophysiologic conditions.AC provided significant insight into mechanical dysfunction in a rapid and noninvasive way that could be used for early screening of PH.

Aggressive Afterload Lowering to Improve the Right Ventricle: A New Target for Medical Therapy in Pulmonary Arterial Hypertension?

Despite numerous therapeutic advances in pulmonary arterial hypertension, patients continue to suffer high morbidity and mortality, particularly considering a median age of 50 years. This article explores whether early, robust reduction of right ventricular afterload would facilitate substantial improvement in right ventricular function and thus whether afterload reduction should be a treatment goal for pulmonary arterial hypertension. The earliest clinical studies of prostanoid treatment in pulmonary arterial hypertension demonstrated an important link between lowering mean pulmonary arterial pressure (or pulmonary vascular resistance) and improved survival. Subsequent studies of oral monotherapy or sequential combination therapy demonstrated smaller reductions in mean pulmonary arterial pressure and pulmonary vascular resistance. More recently, retrospective reports of initial aggressive prostanoid treatment or initial combination oral and parenteral therapy have shown marked afterload reduction along with significant improvements in right ventricular function. Some data suggest that reaching threshold levels for pressure or resistance (components of right ventricular afterload) may be key to interrupting the self-perpetuating injury of pulmonary vascular disease in pulmonary arterial hypertension and could translate into improved long-term clinical outcomes. Based on these clues, the authors postulate that improved clinical outcomes might be achieved by targeting significant afterload reduction with initial oral combination therapy and early parenteral prostanoids.

Additional Use of Prostacyclin Analogs in Patients With Pulmonary Arterial Hypertension: A Meta-Analysis

Background: Combination therapy has become an attractive option in pulmonary arterial hypertension (PAH) treatment. The aim of this study was to investigate whether additional use of prostacyclin analogs could exert any additional benefits over background targeted therapies in PAH patients.

Methods: Searches were performed on PubMed, Embase, and ClinicalTrials.gov from inception to 1 October 2021. Randomized controlled trials were included if patients had been treated with prostacyclin analog-containing combination therapy and compared with the use of other PAH-specific background therapies. The bias risk and statistical analysis of the enrolled studies were performed with RevMan 5.1. Sensitivity analysis and funnel plot were used to evaluate the stability and publication bias, respectively. PROSPERO registered number CRD42021284196.

Results: Ten trials involving 1828 patients were included. Prostacyclin analog treatment was associated with greater improvement in clinical worsening (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.57–0.86), 6-min walk distance (mean difference [MD], 37.17 m; 95% CI, 3.01–71.33 m), NYHA/WHO functional class (RR, 1.58; 95% CI, 1.21–2.05), mean pulmonary artery pressure (MD, −9.23 mmHg; 95% CI, −17.44 to −1.03 mmHg), and cardiac index (MD, 0.41 L/min/m²; 95% CI, 0.26–0.55 L/min/m²) than the control group. No significant differences in pulmonary vascular resistance (MD, −137.22 dyn·s/cm⁵; 95% CI, −272.61 to −1.84 dyn·s/cm⁵) and all-cause mortality (RR, 0.96; 95% CI, 0.57–1.61) were found between the prostacyclin analog group and control group. Of note, more adverse events (RR, 1.07; 95% CI, 1.02–1.13) occurred in the prostacyclin analog group but no significant increase in serious adverse events (RR, 1.25; 95% CI, 0.75–2.11).

Conclusion: Additional prostacyclin analog treatment exerted benefits on clinical worsening, exercise capacity, functional class, mean pulmonary artery pressure, and cardiac index in PAH patients, but it was associated with overall risk of adverse events.

Clinical Trial Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021284196, identifier CRD42021284196.

Safe and successful transition from oral selexipag to subcutaneous treprostinil in a patient with idiopathic pulmonary arterial hypertension treated with triple combination therapy

Learning objectives

Successful epoprostenol withdrawal and termination with an aid of the exercise stress test in pulmonary arterial hypertension

Continuous infusion of intravenous epoprostenol (EPO) improves exercise capacity and survival in pulmonary arterial hypertension (PAH); however, it is associated with side effects. This study aimed to describe our experience on safe EPO withdrawal with the aid of an exercise stress test. This retrospective review included patients with PAH who were successfully withdrawn from EPO. Haemodynamic data were obtained before EPO administration, at withdrawal, and after discontinuation. After the mean pulmonary arterial pressure (mPAP) decreased to <25 mmHg for at least 1 year, an exercise test under right heart catheterisation was performed. If exercise pulmonary hypertension was not record (mPAP - cardiac output slope < 3), EPO was withdrawn. Of the 99 patients who received EPO, ten were identified as having undergone withdrawal or termination. mPAP decreased from 61 (54-71) mmHg before treatment to 19 (17-21) mmHg before withdrawal and remained unchanged, at 19 (14-23) mmHg, 1 year after EPO discontinuation. After a median follow-up of 32 months, all the patients survived. Patients with PAH who recovered their normal haemodynamic function were safely withdrawn from EPO with the aid of an exercise stress test.

Strategies for optimizing intravenous prostacyclin-analog therapy in patients with pulmonary arterial hypertension

INTRODUCTION

Intravenous prostacyclin-analogs (PCA, e.g. epoprostenol, treprostinil, iloprost) have become an essential part in the therapy of patients with pulmonary hypertension (PH), mainly pulmonary arterial hypertension (PAH). They show considerable differences in pharmacology. A combination therapy including intravenous drugs is regarded as the 'gold standard' in most of PAH patients.

AREAS COVERED

This review discusses and summarizes the studies and concepts on which this therapy is based. To date, intravenous prostacyclin-analogs are mainly administered when standard therapy fails to improve patients to low-risk status. However, preliminary data from uncontrolled studies suggest that an 'upfront triple' therapy including intravenous or subcutaneous prostacyclin-analogs could be preferable in selected patients.

EXPERT OPINION

Various IV PCA have been evaluated in the treatment of patients with PAH. Today, combination therapy is the 'gold standard' for the majority of patients. Intravenous PCA is recommended from functional class III onwards. Timing of its initiation is still a point of discussion. An escalation of therapy to IV or SC PCA is always necessary if a low-risk status cannot be achieved with other targeted therapies. Preliminary data suggest that selected patients could benefit from an 'upfront triple' therapy. Controlled studies on which such recommendation could be based are lacking.

Assessment of right ventricle in pulmonary arterial hypertension with three-dimensional echocardiography and cardiovascular magnetic resonance

AIM

To correlate 3-D Echo and CMR RV parameters and to verify whether they are similarly related to the clinical conditions of patients with pulmonary arterial hypertension (PAH), a disease in which the RV plays a crucial prognostic role.

METHODS

We enrolled 34 consecutive PAH patients followed by our PAH clinics. All patients underwent a 3-D Echo and CMR assessment of RV volumes and functions in the same day. The presence or absence of correlation between major findings was investigated; functional RV parameters were also analyzed in relation to 6-min walking test (6MWT) results and BNP/Nt-proBNP plasma levels. Twenty-four subjects served as controls.

RESULTS

Good agreement was found between 3-D Echo and CMR measures of RV volumes [RV-end-diastolic volume (r = 0.72, P < 0.0001), RV-end-systolic volume (ESV) (r = 0.80, P < 0.0001)] and function [RV-EF (r = 0.73, P < 0.0001), RV-ESV/SV (r = 0.83, P = 0.001)] for all the subjects of the study. These correlations were stronger in PAH patients than in control subjects. Importantly, 3-D Echo and CMR RV-EF and RV to pulmonary arterial coupling (RV-ESV/SV) similarly correlated with BNP/Nt-proBNP levels and with functional capacity measured at 6MWT in the PAH patients group.

CONCLUSIONS

3-D Echo demonstrated a significant agreement with CMR in the assessment of RV volume and function in PAH patients. Both techniques showed a similar correlation with clinical and prognostic parameters. The use of 3-D Echo should be amply boosted in the real-world clinical evaluation of PAH patients.

Selexipag for the treatment of chronic thromboembolic pulmonary hypertension

Treatment options for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) remain limited. Selexipag, an oral selective IP prostacyclin-receptor agonist approved for pulmonary arterial hypertension, is a potential treatment option for CTEPH.In this multicentre, randomised, double-blind, placebo-controlled study, 78 Japanese patients with inoperable CTEPH or persistent/recurrent pulmonary hypertension after pulmonary endarterectomy and/or balloon pulmonary angioplasty were randomly assigned to receive placebo or selexipag. The primary endpoint was the change in pulmonary vascular resistance (PVR) from baseline to week 20. The secondary endpoints were changes in other haemodynamic parameters, 6-min walk distance (6 WMD), Borg Dyspnoea Scale score, World Health Organisation (WHO) functional class, EuroQol 5 dimensions 5-level and N-terminal pro-brain natriuretic peptide.The change in PVR was -98.2±111.3 dyn·s·cm^-5 and -4.6±163.6 dyn·s·cm^-5 in the selexipag and placebo groups, respectively (mean difference, -93.5 dyn·s·cm^-5; 95% confidence interval, -156.8, -30.3; p=0.006). The changes in cardiac index (p<0.001) and Borg Dyspnoea Scale score (p=0.036) were also significantly improved over placebo. 6WMD and WHO functional class were not significantly improved. The common adverse events in the selexipag group were corresponded to those generally observed following a prostacyclin analogue is administered.Selexipag significantly improved PVR and other haemodynamic variables in patients with CTEPH, although exercise capacity remained unchanged. Further large-scale investigation is necessary to prove the role of selexipag in CTEPH.

Advanced Circulatory Support and Lung Transplantation in Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive fatal disease. Although medical therapies have improved the outlook for these patients, there still exists a cohort of patients with PAH who are refractory to these therapies. Lung transplantation (LT), and in certain cases heart-lung transplantation (HLT), is a therapeutic option for patients with severe PAH who are receiving optimal therapy yet declining. ECMO may serve as a bridge to transplant or recovery in appropriate patients. Although, the mortality within the first 3 months after transplant is higher in PAH recipients than the other indications for LT, and the long-term survival after LT is excellent for this group of individuals. In this review, we discuss the indications for LT in PAH patients, when to refer and list patients for LT, the indications for double lung transplant (DLT) versus HLT for PAH patients, types of advanced circulatory support for severe PAH, and short and long-term outcomes in transplant recipients with PAH.

Increased Pulmonary Arterial Compliance after Balloon Pulmonary Angioplasty Predicts Exercise Tolerance Improvement in Inoperable CTEPH Patients with Lower Pulmonary Arterial Pressure

BACKGROUND

Balloon pulmonary angioplasty (BPA) improved pulmonary arterial compliance (C_PA) and exercise tolerance in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

OBJECTIVES

To investigate whether C_PA is a useful index to indicate exercise tolerance improvement by BPA in CTEPH patients.

METHODS

The correlation between changes in C_PA and improvements in 6-minute walk distance (6MWD) by BPA was retrospectively analyzed in 70 patients (Analysis 1), and it was sequentially analyzed in 46 symptomatic patients who achieved mean pulmonary arterial pressure (mPAP)<30mmHg (Analysis 2).

RESULTS

We enrolled 70 patients (female/male:57/13, mean age:59 years) who underwent a total of 352 BPA sessions which significantly increased C_PA (1.5±0.8 vs. 3.0±1.0 mL/mmHg) and decreased pulmonary vascular resistance (PVR) (8.0 ± 3.9 vs. 3.6 ± 1.7 wood units). The correlation coefficient between improvement in 6MWD and changes in PVR and C_PA were r=0.21 (p=0.09) and r=0.14 (p=0.26) (Analysis 1). In Analysis 2, those were r=0.32 (p=0.06) and r=0.38 (p=0.02), respectively.

CONCLUSIONS

C_PA can be a useful index to indicate the improvement in exercise tolerance by BPA in symptomatic patients with lower mPAP.

The prognostic significance of the alterations of pulmonary hemodynamics in patients with pulmonary arterial hypertension: a meta-regression analysis of randomized controlled trials

BACKGROUND

Hemodynamic assessment in patients with pulmonary arterial hypertension (PAH) is essential for risk stratification and pharmacological management. However, the prognostic value of the hemodynamic changes after treatment is less well established.

OBJECTIVES

We investigated the prognostic impacts of the changes in hemodynamic indices, including mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), right atrial pressure (RAP), and cardiac output index (CI). We conducted this systematic review with meta-regression analysis on existing clinical trials.

METHODS

We searched and identified all relevant randomized controlled trials from multiple databases. An analogous R² index was used to quantify the proportion of variance explained by each predictor in the association with PAH patients' prognosis. A total of 21 trials and 3306 individuals were enrolled.

RESULTS

The changes in mPAP, PVR, RAP, and CI were all significantly associated with the change in 6MWD (∆6MWD). The change in mPAP was with the highest explanatory power for ∆6MWD (R² analog = 0.740). Additionally, the changes in mPAP, PVR, and CI were independently predictive of adverse clinical events. The change in mPAP had the highest explanatory power for the clinical events (R² analog = 0.911). Furthermore, the change in PVR was with the highest explanatory power for total mortality of PAH patients (R² analog = 0.612).

CONCLUSION

Hemodynamic changes after treatment, including mPAP, PVR, CI, and RAP, were significantly associated with adverse clinical events or mortality in treated PAH patients. It is recommended that further studies be conducted to evaluate the changes in hemodynamic indices to guide drug titration.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019125157.

Evaluation of Pulmonary Hypertension Using 4D Flow MRI

BACKGROUND

Cardiac magnetic resonance imaging (MRI) is becoming an alternative to right heart catheterization (RHC) for evaluating pulmonary hypertension (PH). A need exists to further evaluate cardiac MRI's ability to characterize PH.

PURPOSE

To evaluate the potential for four-dimensional (4D) flow MRI-derived pulmonary artery velocities to characterize PH.

STUDY TYPE

Prospective case-control.

POPULATION

Fifty-four PH patients (56% female); 25 controls (36% female).

FIELD STRENGTH/SEQUENCE

1.5 T; gradient recalled echo 4D flow and balanced steady-state free precession cardiac cine.

ASSESSMENT

RHC was used to derive patients' pulmonary vascular resistance (PVR). 4D flow measured blood velocities at the main, left, and right pulmonary arteries (MPA, LPA, and RPA); cine measured ejection fraction, end diastolic, and end systolic volumes (EF, EDV, and ESV). EDV and ESV were normalized (indexed) to body surface area (ESVI and EDVI). Parameters were evaluated between, and within, PH subgroups: pulmonary arterial hypertension (PAH); PH due to left heart disease (PH-LHD)/chronic lung disease (PH-CLD)/or chronic thrombo-emboli (CTE-PH).

STATISTICAL TESTS

Analysis of variance and Kruskal-Wallis tests compared parameters between subgroups. Pearson's r assessed velocity, PVR, and volume correlations. Significance definition: P < 0.05.

RESULTS

PAH peak and mean velocities were significantly lower than in controls at the LPA (36 ± 12 cm/second and 20 ± 4 cm/second vs. 59 ± 15 cm/second and 32 ± 9 cm/second). At the RPA, mean velocities were significantly lower in PAH vs. controls (27 ± 6 cm/second vs. 40 ± 9 cm/second). Peak velocities significantly correlated with right ventricular EF at the MPA (r = 0.286), RPA (r = 0.400), and LPA (r = 0.401). Peak velocity significantly correlated with right ventricular ESVI at the RPA (r = -0.355) and LPA (r = -0.316). Significant correlations between peak velocities and PVR were moderate at the LPA in PAH (r = -0.641) and in PH-LHD (r = -0.606) patients, and at the MPA in PH-CLD (r = -0.728). CTE-PH showed non-significant correlations between peak velocity and PVR at all locations.

DATA CONCLUSION

Preliminary findings suggest 4D flow can identify PAH and track PVR changes.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 5.

The role of intraoperative pulmonary arterial catheterization data in determining the need for extracorporeal membrane oxygenation in lung transplantation

Background

This study aims to investigate predictive factors of identification of the need of patients for extracorporeal membrane oxygenation support during lung transplantation.

Methods

A total of 63 patients (49 males, 14 females, mean age: 44.9±14.4 years; range, 14 to 64 years) who underwent lung transplantation in our institution between December 2016 and December 2019 were retrospectively analyzed. Demographic characteristics and perioperative clinical data of patients were recorded. After induction and pulmonary artery catheterization, cardiac output, mean pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac index, pulmonary vascular resistance, systemic vascular resistance, and right atrial pressure were measured using the thermodilution technique.

Results

Thirty-three of the patients received extracorporeal membrane oxygenation support during surgery. The right atrial pressure (p<0.001), pulmonary capillary wedge pressure (p<0.002), mean pulmonary artery pressure (p<0.001), and pulmonary vascular resistance (p<0.001) were statistically significantly higher in the patients who required extracorporeal membrane oxygenation support intraoperatively. The systemic vascular resistance (p<0.032) was statistically significantly lower in the patients who required extracorporeal membrane oxygenation support intraoperatively. A mean pulmonary artery pressure of >39 mmHg (p<0.02) and a right atrial pressure of >12 mmHg (p<0.047) were independent risk factors for ECMO support intraoperatively during lung transplantation.

Conclusion

Predicting the need of intraoperative extracorporeal membrane oxygenation support is of utmost importance in timing the need for mechanical support, protecting the new graft from high mechanical ventilator pressures, and adequately maintaining hemodynamic stability.

Maximal Exercise Testing Using the Incremental Shuttle Walking Test Can Be Used to Risk-Stratify Patients with Pulmonary Arterial Hypertension

Rationale: Exercise capacity predicts mortality in pulmonary arterial hypertension (PAH), but limited data exist on the routine use of maximal exercise testing.

Objectives: This study evaluates a simple-to-perform maximal test (the incremental shuttle walking test) and its use in risk stratification in PAH.

Methods: Consecutive patients with pulmonary hypertension were identified from the ASPIRE (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) registry (2001–2018). Thresholds for levels of risk were identified at baseline and tested at follow-up, and their incorporation into current risk stratification approaches was assessed.

Results: Of 4,524 treatment-naive patients with pulmonary hypertension who underwent maximal exercise testing, 1,847 patients had PAH. A stepwise reduction in 1-year mortality was seen between levels 1 (≤30 m; 32% mortality) and 7 (340–420 m; 1% mortality) with no mortality for levels 8–12 (≥430 m) in idiopathic and connective tissue disease–related PAH. Thresholds derived at baseline of ≤180 m (>10%; high risk), 190–330 m (5–10%; intermediate risk), and ≥340 m (<5%; low risk of 1-yr mortality) were applied at follow-up and also accurately identified levels of risk. Thresholds were incorporated into the REVEAL (Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management) 2.0 risk score calculator and French low-risk approach to risk stratification, and distinct categories of risk remained.

Conclusions: We have demonstrated that maximal exercise testing in PAH stratifies mortality risk at baseline and follow-up. This study highlights the potential value of the incremental shuttle walking test as an alternative to the 6-minute walking test, combining some of the advantages of maximal exercise testing and maintaining the simplicity of a simple-to-perform field test.

The Role of Exercise Testing in Pulmonary Vascular Disease: Diagnosis and Management

Exercise intolerance is the dominant symptom of pulmonary hypertension (PH). The gold standard for the estimation of exercise capacity is a cycle ergometer incremental cardiopulmonary exercise test (CPET). The main clinical variables generated by a CPET are peak oxygen uptake (Vo2peak), ventilatory equivalents for carbon dioxide (VE/Vco₂), systolic blood pressure, oxygen (O2) pulse, and chronotropic responses. PH is associated with hyperventilation at rest and at exercise, and an increase in physiologic dead space. Maximal cardiac output depends on right ventricular function and critically determines a PH patient's exercise capacity. Dynamic arterial O2 desaturation can also depress the Vo2peak.

Epoprostenol for the treatment of pulmonary arterial hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a rare, progressive, and severe disease. Since the first demonstration of survival benefit of intravenous epoprostenol in monotherapy in 1996, prostanoids remain the cornerstone for PAH patients at high risk. This review is essential to understand the current situation of this drug among all the therapeutic possibilities concerning this entity.Areas covered: The aim of this article is to review the pharmacological properties of epoprostenol and to update its clinical evidence in different specific clinical scenarios. A deep literature search was carried out on the MEDLINE database for published literature before March 2021.Expert opinion: Epoprostenol is still the best treatment option for high-risk PAH patients. Nevertheless, there are many unsolved questions: drug dosing, its use in combination therapy with other pulmonary vasodilators, and the utility in PAH associated with connective tissue disease, congenital heart disease, or pulmonary veno-occlusive disease are only a few examples. Its safety and efficacy are supported by clinical trials, observational work, and experience, both as monotherapy and in combination therapy. Epoprostenol should be considered a destination treatment in high-risk patients and not only as a bridge to pulmonary transplantation. However, it remains underused in clinical practice.

Soluble ST2 and mixed venous oxygen saturation for prediction of mortality in patients with pulmonary hypertension

Background

Although soluble suppression of tumorigenicity-2 (sST2) has been identified as a clinical biomarker for pulmonary hypertension (PH) by previous studies, the implication of sST2 combined with hemodynamic parameters in PH has not been well studied. This study aimed to evaluate the relationship between sST2 and hemodynamic parameters and to evaluate the predictive value of sST2 for mortality in patients with PH.

Methods

One hundred eighty-four incident patients with PH and 14 healthy controls were retrospectively enrolled by Shanghai Pulmonary Hospital for this retrospective study. After all patients underwent right heart catheterization, blood samples were collected and serum sST2 concentration was assessed by the Presage™ ST2 assay. Kaplan-Meier curve and Cox regression analyses were used to predict survival and the association between survival and different factors such as sST2, SvO₂.

Results

During a follow-up of 44.9 (IQR 28.5–64.4) months, 65 patients died. The median concentration of sST2 in PH patients was 33.1 ng/mL, which is higher than that in control group (23.1 ng/mL, P=0.005). Furthermore, for PH group, the level of sST2 was higher in non-survivors than that in survivors. Cox regression analyses demonstrated that sST2 and SvO₂ were independent risk factors for survival. In Kaplan-Meier curve analyses, elevated sST2 level and reduced SvO₂ predicted a poor outcome for patients with PH.

Conclusions

Higher sST2 was independently associated with increased mortality, as well as lower SvO₂ in patients with PH. Especially, the combination of higher sST2 and lower SvO₂ had the strongest predictive value of mortality in patients with PH.

Arm span as a predictor of the six-minute walk test in healthy children

BACKGROUND

Six-minute walk test (6MWT) is the most used test to assess functional capacity. Including arm span in the prediction equations for 6MWT performance might be an alternative for use in traditional reference equations.

OBJECTIVE

The aim was to investigate the usability of arm span to predict the 6MWT distance in healthy children.

METHODS

262 healthy children aged between 6 and 12 years old participated in this study. 6MWT was conducted according to the standardized protocol. Height, weight, and arm span were measured before performing the 6MWT. A multiple stepwise linear regression analysis was used to generate the regression model.

RESULTS

The 6MWT distance had strong positive correlations with age, arm span, height, and weight (p<0.001). There was also a very strong correlation between arm span and height (p<0.001). Age and arm span were found as significant predictors in the first regression model. These two variables explained 60.2% of the variance in the 6MWT distance. Age and height were also found as significant predictors, explaining 60.5% of the variance in the 6MWT distance. The two following formula were obtained to predict the 6MWT distance: (-23.09+(31.12×Age)+(2.39×Arm span)) or (-80.0+(28.98×Age)+(2.92×Height)).

CONCLUSIONS

The results suggest that the combination of arm span (or height) and age are strong predictors of the 6MWT distance in healthy children.