Advances in balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

Effects of medical therapy and age on cardiac output changes following balloon pulmonary angioplasty: Implications for combination therapy in chronic thromboembolic pulmonary hypertension

BACKGROUND

Some patients with chronic thromboembolic pulmonary hypertension (CTEPH) exhibit exercise intolerance due to reduced cardiac output (CO) even after successful balloon pulmonary angioplasty (BPA). Medical therapy is a potential option for such cases; however, it is unclear which patients necessitate it even after BPA.

METHODS

This study included 286 patients with CTEPH who underwent BPA and right heart catheterization 1 year after the final BPA and classified them into no-medication and withdrawal groups. The no-medication group comprised patients without pulmonary hypertension (PH) medications before and after BPA, while the withdrawal group included patients who received PH medications before BPA and discontinued them after BPA. We assessed differences in the changes in CO after BPA from baseline (ΔCO) between the 2 groups. Additionally, we evaluated the ΔCO among different age categories within each group: younger (<60 years), middle-aged (60-70 years), and older adults (≥70 years).

RESULTS

After adjusting baseline covariates, overall CO did not differ significantly. However, ΔCO was significantly positive in the no-medication group but negative in the withdrawal group (0.32 and -0.33, difference in ΔCO: -0.65, 95% confidence intervals: -0.90 to -0.40). A significantly positive effect on ΔCO was observed in younger and middle-aged individuals, with a significant interaction between age and ΔCO in no-medication groups.

CONCLUSIONS

Increasing CO with BPA alone may be challenging with age in patients with CTEPH. Given that discontinuation of PH medication after BPA decreased CO more than the effect of BPA, medical therapy might be necessary even after successful BPA.

Usefulness of risk assessment tools in predicting hemodynamic outcome after balloon pulmonary angioplasty: a comparative analysis

OBJECTIVES

Several parameters of widely used risk assessment tools for pulmonary arterial hypertension (PAH) have been linked to hemodynamic outcomes of balloon pulmonary angioplasty (BPA). Therefore, we aimed to determine whether these risk assessment tools could be used to predict hemodynamic outcomes following BPA.

METHODS

In this retrospective study, we included 139 patients with chronic thromboembolic pulmonary hypertension who had undergone BPA at Center for Pulmonary Vascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College (Beijing, China). We compared the accuracies of seven well-validated risk assessment tools for predicting hemodynamic outcomes following BPA. A favorable hemodynamic outcome was defined as a mean pulmonary arterial pressure < 30 mmHg at follow-up.

RESULTS

The baseline risk profiles varied significantly among the risk assessment tools. The US Registry to Evaluate Early and Long-Term PAH Disease Management risk scales and the French risk assessment tools rated most patients as high-risk, while the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) series and laboratory examination-based risk scales categorized most patients as having intermediate-risk profile. COMPERA 2.0 (4-strata) exhibited the highest predictive power among all risk stratifications. Noninvasive risk stratification (COMPERA 2.0 [3-strata]) showed a comparable predictive ability to that of invasive risk stratification (COMPERA 1.0) (area under the curve 0.649 vs. 0.648). Moreover, incorporating diffusing capacity of the lungs for carbon monoxide and tricuspid regurgitation velocity into COMPERA 2.0 (4-strata) further enhanced its predictive power (net reclassification index 0.153, 95% confidence interval 0.009-0.298, p = 0.038). Additionally, this refined COMPERA version had a high calibration accuracy (slope 0.96).

CONCLUSION

Although the risk strata distribution varied among different risk assessment tools, the proportion of patients achieving favorable hemodynamics decreased with the escalation of risk stratification in most models. The well-validated risk assessment tools for PAH could also predict hemodynamic outcomes following BPA, and the refined COMPERA 2.0 model exhibited the highest predictive ability among these. Applying risk assessment tools before BPA can facilitate early identification of patients in need of closer monitoring and more intensive interventions, contributing to a better prognosis after BPA.

Status and Future Directions for Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Disease With and Without Pulmonary Hypertension: A Scientific Statement From the American Heart Association

Balloon pulmonary angioplasty continues to gain traction as a treatment option for patients with chronic thromboembolic pulmonary disease with and without pulmonary hypertension. Recent European Society of Cardiology guidelines on pulmonary hypertension now give balloon pulmonary angioplasty a Class 1 recommendation for inoperable and residual chronic thromboembolic pulmonary hypertension. Not surprisingly, chronic thromboembolic pulmonary hypertension centers are rapidly initiating balloon pulmonary angioplasty programs. However, we need a comprehensive, expert consensus document outlining critical concepts, including identifying necessary personnel and expertise, criteria for patient selection, and a standardized approach to preprocedural planning and establishing criteria for evaluating procedural efficacy and safety. Given this lack of standards, the balloon pulmonary angioplasty skill set is learned through peer-to-peer contact and training. This document is a state-of-the-art, comprehensive statement from key thought leaders to address this gap in the current clinical practice of balloon pulmonary angioplasty. We summarize the current status of the procedure and provide a consensus opinion on the role of balloon pulmonary angioplasty in the overall care of patients with chronic thromboembolic pulmonary disease with and without pulmonary hypertension. We also identify knowledge gaps, provide guidance for new centers interested in initiating balloon pulmonary angioplasty programs, and highlight future directions and research needs for this emerging therapy.

Nationwide trends of balloon pulmonary angioplasty and pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension (2012-2019)

Chronic thromboembolic pulmonary hypertension (CTEPH) is a sequela of a pulmonary embolus that occurs in approximately 1%-3% of patients. Pulmonary thromboendoarterectomy (PTE) can be a curative procedure, but balloon pulmonary angioplasty (BPA) has emerged as an option for poor surgical candidates. We used the National Inpatient Sample to query patients who underwent PTE or BPA between 2012 and 2019 with CTEPH. The primary outcome was a composite of in-hospital mortality, myocardial infarction, stroke, tracheostomy, and prolonged mechanical ventilation. Outcomes were compared between low- and high-volume centers, defined as 5 and 10 procedures per year for BPA and PTE, respectively. During our study period, 870 BPA and 2395 PTE were performed. There was a 328% relative increase in the number of PTE performed during the study period. Adverse events for BPA were rare. There was an increase in the primary composite outcome for low-volume centers compared to high-volume centers for PTE (24.4% vs. 12.1%, p = 0.003). Patients with hospitalizations for PTE in low-volume centers were more likely to have prolonged mechanical ventilation (20.0%% vs. 7.2%, p < 0.001) and tracheostomy (7.8% vs. 2.6%, p = 0.017). In summary, PTE rates have been rising over the past 10 years, while BPA rates have remained stable. While adverse outcomes are rare for BPA, patients with hospitalizations at low-volume centers for PTE were more likely to have adverse outcomes. For patients undergoing treatment of CTEPH with BPA or PTE, referral to high-volume centers with multidisciplinary teams should be encouraged for optimal outcomes.

The beneficial effects of balloon pulmonary angioplasty for patients with chronic thromboembolic pulmonary hypertension are accompanied by increased body mass index and improved nutritional status

Although balloon pulmonary angioplasty (BPA) improves pulmonary hypertension and the prognosis of patients with chronic thromboembolic pulmonary hypertension (CTEPH), subsequent changes in body mass index (BMI), nutritional status, and appetite have not been fully investigated. This retrospective study aimed to clarify changes in BMI, nutritional status, and appetite after BPA. Fifty-two consecutive patients with CTEPH who underwent complete revascularization with BPA between July 2014 and July 2023 and were available for follow-up were evaluated. We compared the presence or absence of increased appetite, BMI change, and nutritional status before and after BPA treatment. BPA significantly improved the mean pulmonary artery pressure from 37.4 ± 8.7 mmHg to 18.7 ± 2.8 mmHg and the partial pressure of oxygen from 61.6 ± 9.3 mmHg to 82.8 ± 9.9 mmHg (both p < 0.001). Appetite was increased in 82.7% of the patients. BMI significantly increased from 23.9 ± 3.7 kg/m2 to 24.9 ± 3.7 kg/m2 (p < 0.001). As a nutritional indicator, the Geriatric Nutritional Risk Index increased from 105.3 ± 10.2 to 108.3 ± 8.3 (p < 0.001). The median Controlling Nutritional Status scores showed no significant change but the range was significantly improved from 0-9 to 0-3 (p = 0.006). In conclusion, patients with CTEPH show improved oxygenation and hemodynamics, increased BMI, and improved nutritional status following BPA. This sequence of changes may help improve patient prognosis.

Development and validation of a nomogram for predicting hemodynamic response to balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Balloon pulmonary angioplasty (BPA) can effectively alleviate pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Identifying predictors of unfavorable hemodynamic response to BPA is essential to guide clinical practice. Therefore, our objective was to construct and validate a nomogram to facilitate clinicians predicting hemodynamic response to BPA.

METHODS

Patients with CTEPH and underwent BPA from May 2018 to April 2022 were retrospectively collected. Favorable hemodynamic response to BPA was defined as a mean pulmonary arterial pressure ≤30 mmHg and/or a reduction in pulmonary vascular resistance ≥30 % at follow-up.

RESULTS

A total of 155 patients were included. At baseline, patients with favorable hemodynamic response had significantly lower proportion of occlusive lesions (11.11 % vs. 26.32 %, P = 0.017), higher diffusing capacity of the lungs for carbon monoxide (63.77 % ± 14.10 % vs. 59.11 % ± 11.78 %, P = 0.039), and better cardiac morphology than counterparts. LASSO regression and random forest were used to construct prediction models respectively. The LASSO regression model demonstrated better predictive ability and accuracy than the random forest model, as evidenced by higher area under curve (0.745 vs. 0.740) and lower Brier score (0.192 vs. 0.195). A nomogram was constructed based on the LASSO regression model, consisting of right ventricular end-diastolic diameter/left ventricular end-diastolic diameter, number of treated pulmonary vessels and proportion of occlusion lesions. High predictive ability of the LASSO model was preserved in validation (C index 0.744).

CONCLUSIONS

The current study constructed a nomogram with high accuracy in predicting BPA hemodynamic outcome, which could facilitate decision-making in clinical practice.

Monographic Issue on Pulmonary Hypertension: Medical and Interventional Treatment for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. The reasons why clots do not resorb are incompletely understood, but the result is partial or complete fibrothrombotic obstruction of pulmonary arteries. A secondary microvasculopathy aggravates the pulmonary hypertension (PH) as a consequence of high flow and shear stress in the nonoccluded arteries. The treatment of CTEPH has long been purely surgical, but many patients were inoperable because of inaccessible lesions or severe comorbidities. Alternatives were developed, including medical therapy and more recently balloon pulmonary angioplasty (BPA). Depending on the generation of the obstructed vessels, the treatment will be surgical, up to the (sub)segmental level, or by BPA for more distal vessels. PH drugs are used to treat the microvasculopathy. The current paper describes the therapeutic management of inoperable patients: the medical approach with PH drugs used in mono- or combination therapy; the proper use of anticoagulants in CTEPH; the technique, indications, and results at short- and long-term of BPA; the multimodal approach for inoperable patients combining PH drugs and BPA; and the effects of rehabilitation. It shows the importance of a multidisciplinary approach to the disease.

Updates in the diagnosis and management of chronic thromboembolic disease

PURPOSE OF REVIEW

Chronic thromboembolic disease (CTED) is distinct from chronic thromboembolic pulmonary hypertension (CTEPH) and is defined by dyspnea on exertion after acute pulmonary embolism with the presence of residual perfusion defects and absence of resting pulmonary hypertension. Here, we review clinical features and diagnostic criteria for CTED and summarize treatment options.

RECENT FINDINGS

The optimal management for CTED is unclear as the long-term outcomes of conservative vs. invasive treatment for this disease have not been reported. There are a few studies evaluating outcomes of pulmonary thromboendarterectomy and balloon pulmonary angioplasty (BPA) in CTED, concluding that these procedures are safe and effective in select patients. However, these trials are small nonrandomized observational studies, reporting outcomes only up to 1 year after the intervention. Conservative management of CTED with observation, pulmonary hypertension-targeted therapy, or cardiopulmonary rehabilitation has not been studied. It is unknown whether these treatments are as effective or superior to pulmonary thromboendarterectomy or BPA in CTED.

SUMMARY

The management of CTED is individualized and based on symptoms and exercise limitations. Early referral of patients with CTED to a specialized CTEPH center is recommended to determine if watchful waiting, BPA, or pulmonary thromboendarterectomy is most beneficial.

Patient-Reported Long-Term Outcome of Balloon Pulmonary Angioplasty for Inoperable CTEPH

BACKGROUND

 Balloon pulmonary angioplasty (BPA) is a promising interventional treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Evidence in favor of BPA is growing, but long-term data remain scarce. The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) is validated for the assessment of patients with pulmonary hypertension within three domains: symptoms, activity, and quality of life (QoL). The aim of the present study was to evaluate the long-term effects of BPA on these domains in patients with inoperable CTEPH.

METHODS

 Between March 2014 and August 2019, technically inoperable patients with target lesions for BPA were included in this prospective, observational study. CAMPHOR scores were compared between baseline (before the first BPA) and 6 months after the last intervention and also for scores assessed at annual follow-ups.

RESULTS

 A total of 152 patients had completed a full series of BPA interventions and a 28 (interquartile range [IQR]: 26-32) week follow-up. Further follow-up assessments including the CAMPHOR score were performed 96 (IQR: 70-117) weeks, 178 (IQR: 156-200) weeks, and 250 (IQR: 237-275) weeks after the last intervention. From baseline to the last follow-up, CAMPHOR scores for symptoms, activity, and QoL improved from 9 (IQR: 6-14) to 3 (IQR: 0-9) (p < 0.001), 8 (IQR: 5-12) to 4 (IQR: 2-8) (p < 0.001), and 5 (IQR: 2-9) to 1 (IQR: 0-5) (p < 0.001).

CONCLUSION

 BPA leads to long-lasting, significant improvement of symptoms, physical capacity, and QoL in inoperable CTEPH patients.

Impact of Balloon Pulmonary Angioplasty on Right Ventricular Function in Patients With Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) can develop in some patients after an acute pulmonary embolism. The disease is characterized by the conversion of emboli into fibrotic thrombi that chronically impede normal circulation through the pulmonary arteries and increase pulmonary vascular resistance. Over time, this increases right ventricular (RV) afterload and strains the RV. The RV compensates by undergoing cardiomyocyte hypertrophy and RV dilation that can maintain stroke volume. However, these adaptations eventually decrease cardiac output and lead to right heart failure. Balloon pulmonary angioplasty has been developed as a treatment option for CTEPH by systematically disrupting thrombosed vessels and improving blood flow throughout the pulmonary circulation. This ultimately reverses the structural maladaptation's seen in CTEPH and improves RV function.

Distal vessel pulmonary thromboendarterectomy: Results from a single institution

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is primarily managed by pulmonary thromboendarterectomy (PTE). As advanced surgical techniques permit resection at the segmental and subsegmental level, PTE can now be curative for CTEPH mostly involving the distal pulmonary arteries.

METHODS

Between January 2017 and June 2021, consecutive patients undergoing PTE were categorized according to the most proximal level of chronic thrombus resection: Level I (main pulmonary artery), Level II (lobar), Level III (segmental) and Level IV (subsegmental). Proximal disease patients (any Level I or II) were compared to distal disease (Level III or IV bilaterally) patients. Demographics, medical history, preoperative pulmonary hemodynamics, and immediate postoperative outcomes were obtained for each group.

RESULTS

During the study period, 794 patients underwent PTE, 563 with proximal disease and 231 with distal disease. Patients with distal disease more frequently had a history of an indwelling intravenous device, splenectomy, upper extremity thrombosis or use thyroid replacement and less often had prior lower extremity thrombosis or hypercoagulable state. Despite more use of PAH-targeted medications in the distal disease group (63.2% vs 50.1%, p < 0.001), preoperative hemodynamics were similar. Both patient groups exhibited significant improvements in pulmonary hemodynamics postoperatively with comparable in-hospital mortality rates. Compared to proximal disease, a lower percentage of patients with distal disease showed residual pulmonary hypertension (3.1% vs 6.9%, p = 0.039) and airway hemorrhage (3.0% vs 6.6%, p = 0.047) postoperatively.

CONCLUSIONS

Thromboendarterectomy for distal (segmental and subsegmental) CTEPH is technically feasible and may result in favorable pulmonary hemodynamic outcomes, without increased mortality or morbidity.

Evaluation and Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a treatable form of pulmonary hypertension and right heart failure. CTEPH (group 4 pulmonary hypertension) is caused by persistent organized thromboembolic obstruction of the pulmonary arteries from incompletely resolved acute pulmonary embolism. CTEPH also may present without prior VTE history, which can contribute to its underrecognition. The true incidence of CTEPH is unclear, but is estimated to be approximately 3% after acute pulmonary embolism. V˙/Q˙ scintigraphy is the best screening test for CTEPH, with CT scan imaging and other advanced imaging methods now playing a larger role in disease detection and confirmation. Perfusion defects on V˙/Q˙ scintigraphy in the setting of pulmonary hypertension are suggestive of CTEPH, but pulmonary angiography and right heart catheterization are required for confirmation and treatment planning. CTEPH potentially is curative with pulmonary thromboendarterectomy surgery, with mortality rates of approximately 2% at expert centers. Advances in operative techniques are allowing more distal endarterectomies to be performed successfully with favorable outcomes. However, more than one-third of patients may be considered inoperable. Although these patients previously had minimal therapeutic options, effective treatments now are available with pharmacotherapy and balloon pulmonary angioplasty. Diagnosis of CTEPH should be considered in all patients with suspicion of pulmonary hypertension. Treatments for CTEPH have advanced with improvements in outcomes for both operable and inoperable patients. Therapy should be tailored based on multidisciplinary team evaluation to ensure optimal treatment response.

Management of Complications of Balloon Pulmonary Angioplasty

Since the publication of the first case series reporting the outcomes of patients with chronic thromboembolic pulmonary hypertension who underwent treatment with balloon pulmonary angioplasty more than 30 years ago, significant improvements to the procedural technique have made balloon pulmonary angioplasty (BPA) a safe and effective therapy that we know today. Nevertheless, BPA carries a small risk of complications, which require rapid recognition and immediate management. The most commonly seen complications associated with BPA include pulmonary vascular injury and reperfusion pulmonary edema.

Evolving Role and Clinical Evidence in the Global Practice of Balloon Pulmonary Angioplasty

Balloon pulmonary angioplasty (BPA) was first described in 2001 and now has evolved into a class I indication for inoperable or residual chronic thromboembolic pulmonary hypertension. This review article aims to describe evidence from studies performed at various pulmonary hypertension (PH) centers across the globe, to better understand the role of BPA in chronic thromboembolic pulmonary disease with and without PH. Additionally, we hope to highlight innovations and the ever-changing safety and efficacy profile of BPA.

Refined Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension: Initial Results of U.S. Regional Program

Objectives

We sought to evaluate the efficacy and safety of refined balloon pulmonary angioplasty (BPA) in the treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Background

BPA is rapidly evolving therapeutic option for patients with nonsurgical CTEPH. There are few US studies that have reported on the outcomes of this novel therapeutic option.

Methods

This is a retrospective study of CTEPH patients that underwent BPA at Temple University Hospital. The primary efficacy endpoint was the change in pulmonary vascular resistance (PVR) after BPA as compared to baseline and the primary safety endpoint was the rate of hemoptysis within 24 hours. Secondary endpoints included death, WHO functional class, and 6-minute walk distance (6MWD). We used logistic regression to evaluate factors associated with a hemodynamic and functional response.

Results

A total of 211 BPA sessions were performed on 77 patients (average 2.7 ± 1.7 sessions/patient). After BPA the mean PVR improved by 26% (P<0.001) while the mean 6MWD improved by 71.7 meters (P <0.001) and WHO functional class improved by one functional class (P <0.001). Ten sessions (4.7%) were complicated by hemoptysis. The independent factors associated with a improved functional and hemodynamic response included the pre-procedural use of riociguat, reduce baseline PA compliance and > 3 BPA sessions per patient.

Conclusion

This single center study from the US showed that BPA with refined techniques in patients with CTEPH was safe and was associated with significant improvements in pulmonary hemodynamics and functional capacity.

Periprocedural Complications With Balloon Pulmonary Angioplasty: Analysis of Global Studies

BACKGROUND

Balloon pulmonary angioplasty (BPA) was introduced as a treatment modality for patients with inoperable, medically refractory chronic thromboembolic pulmonary hypertension decades ago; however, reports of high rates of pulmonary vascular injury have led to considerable refinement in procedural technique.

OBJECTIVES

The authors sought to better understand the evolution of BPA procedure-related complications over time.

METHODS

The authors conducted a systematic review of original articles published by pulmonary hypertension centers globally and performed a pooled cohort analysis of procedure-related outcomes with BPA.

RESULTS

This systematic review identified 26 published articles from 18 countries worldwide from 2013 to 2022. A total of 1,714 patients underwent 7,561 total BPA procedures with an average follow up of 7.3 months. From the first period (2013-2017) to the second period (2018-2022), the cumulative incidence of hemoptysis/vascular injury decreased from 14.1% (474/3,351) to 7.7% (233/3,029) (P < 0.01); lung injury/reperfusion edema decreased from 11.3% (377/3,351) to 1.4% (57/3,943) (P < 0.01); invasive mechanical ventilation decreased from 0.7% (23/3,195) to 0.1% (4/3,062) (P < 0.01); and mortality decreased from 2.0% (13/636) to 0.8% (8/1,071) (P < 0.01).

CONCLUSIONS

Procedure-related complications with BPA, including hemoptysis/vascular injury, lung injury/reperfusion edema, mechanical ventilation, and death, were less common in the second period (2018-2022), compared with first period (2013-2017), likely from refinement in patient and lesion selection and procedural technique over time.

Establishing a balloon pulmonary angioplasty program for chronic thromboembolic pulmonary hypertension: A United States single-center experience

INTRODUCTION

Balloon pulmonary angioplasty (BPA) is a less invasive treatment alternative for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are unable to move forward with pulmonary thromboendarterectomy. This report describes a single-center experience with a nascent BPA program in the United States (US).

METHODS

All patients who underwent BPA between August 2018-2021 were included in this retrospective, single-center observational cohort. Pre- and post-procedure clinical information was collected, along with procedural characteristics.

RESULTS

Thirty patients began their BPA series during the study period. The majority of patients had segmental disease (n = 25, 83.3%). A total of 135 BPA procedures were performed on 417 segments. On average, patients completed 4.5 sessions and the majority of patients (n = 23, 76.7%) underwent more than 2. There were 24 episodes of hemoptysis and 20 procedural events that required treatment, typically with either heparin reversal or balloon tamponade. Of 26 participants with completed series, mean PA pressure (-6 mmHg, 95% CI -9 to -4 mmHg, p = 0.0001), PVR (-1.9 Wood units, 95% CI -2.9 to -1.0, p = 0.0002), and pulmonary compliance (-1.0 mL/mmHg, 95% CI -1.5 to -0.5, p = 0.0002) improved. Improvement was also seen in NYHA functional classification and walk distance (p = 0.01). Two deaths occurred, with one death peri-procedurally.

CONCLUSION

This paper describes an early experience with BPA at a single US center. Improvement in non-invasive and invasive metrics were seen without adding a significant morbidity to an already high-risk patient population.

Pulmonary Hypertension Association's 2022 International Conference Scientific Sessions Overview

The considerable progress made in recent years in the diagnosis, risk stratification, and treatment of pulmonary hypertension was highlighted during the most recent edition of the Pulmonary Hypertension Association Scientific Sessions, which was held in Atlanta, Georgia from June 9 to 11, 2022, with the theme: Vision for the PHuture: The Evolving Science and Management of PH. Content presented over the 3-day conference focused on scientific and management updates since the last sessions were held in 2018 and included didactic talks, debates, and roundtable discussions across a broad spectrum of topics related to pulmonary hypertension. This article aims to summarize the key messages from each of the session talks.

Riociguat and balloon pulmonary angioplasty improve prognosis in patients with inoperable chronic thromboembolic pulmonary Hypertension

BACKGROUND

The combination of riociguat and interventional balloon pulmonary angioplasty (BPA) is currently used to treat patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). The aim of the present study was to evaluate the impact of this combination therapy on the prognosis of inoperable CTEPH patients by comparing the long-term survival rates of patients undergoing combination therapy with riociguat and BPA with those of inoperable patients from the first international CTEPH registry who did not receive specific treatment.

METHODS

Between March 2014 and August 2019, 138 technically inoperable patients were included in the present prospective, observational cohort study when they were treated with riociguat and BPA at a single CTEPH referral center. Long-term survival of this cohort was compared using propensity score matching with that of inoperable patients recruited between 2007 and 2009 in the first international CTEPH registry. Kaplan-Meier methods were used to evaluate differences in outcomes.

RESULTS

Whereas the survival rate in the historical group was 84.6% in the first year, 76.6% in the second, 68.5% in the third, and 58.5% in the fifth year after diagnosis, implementation of riociguat/BPA led to survival rates of 100%, 96.7%, 92.9%, and 90% in the respective follow-up periods. In a comparison of 83 well-matched pairs from the 2 cohorts, survival was markedly better in the group treated with riociguat and BPA than in the historical cohort (HR = 0.145, 95% CI 0.05, 0.421).

CONCLUSION

The combination of riociguat and BPA for the treatment of inoperable CTEPH is associated with excellent 5-year survival rates.

Update on balloon pulmonary angioplasty for treatment of chronic thromboembolic pulmonary hypertension

PURPOSE OF REVIEW

To provide an update on balloon pulmonary angioplasty (BPA) for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), a pulmonary vascular disease that is characterized by fibro-thrombotic material mechanically obliterating major pulmonary arteries, resulting in increased pulmonary vascular resistance (PVR), progressive pulmonary hypertension (PH) combined with a microscopic pulmonary vasculopathy [1▪▪], right ventricular (RV) failure [2] and premature death.

RECENT FINDINGS

Data from a most recent CTEPH European registry (2015 and 2016) suggest significantly improved survival [3▪] of CTEPH patients compared with survival in the eighties [4], or with data from 2007 and 2009 [5]. Pulmonary endarterectomy (PEA) is still the gold-standard therapy for CTEPH [6,7]. However, only around two thirds of all CTEPH patients are amenable to surgery [3▪,5]. Patients not suitable for PEA and treated conservatively have a poor prognosis [8]. BPA may have a role for this particular group of patients. [9-11]. Currently, BPA programs are available in many countries, with excellent results at expert centers [12-15,16▪,17,18▪▪]. Based on recent data, BPA seems to have a greater impact on symptomatic and hemodynamic improvement than medical therapy with riociguat alone [15].

SUMMARY

The evidence favoring BPA is growing, but there is still a lack of published controlled trials. In addition, treatment concepts including indication, technical performance, use of PH-targeted medication, and the concept of follow-up vary between centers. In addition, there is a significant learning curve impacting outcomes [13]. The data from the International BPA registry will provide answers for some of the open questions.

Chronic Thromboembolic Pulmonary Hypertension: An Observational Study

Background and Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) has a high mortality. The treatment of CTEPH could be balloon pulmonary angioplasty (BPA), medical (MT) or pulmonary endarterectomy (PEA). This study aims to assess the clinical characteristics of CTEPH patients, surgically or medically treated, in a pulmonology referral center. Materials and Methods: A total of 124 patients with PH with suspected CTEPH (53 male subjects and 71 female subjects; mean age at diagnosis 67 ± 6) were asked to give informed consent and then were evaluated. The presence of CTEPH was ascertained by medical evaluations, radiology and laboratory tests. Results: After the evaluation of all clinical data, 65 patients met the inclusion criteria for CTEPH and they were therefore enrolled (22 males and 43 females; mean age at diagnosis was 69 ± 8). 26 CTEPH patients were treated with PEA, 32 with MT and 7 with BPA. There was a statistically significant age difference between the PEA and MT groups, at the time of diagnosis, the PEA patients were younger than the MT patients, whereas there was no statistically significant difference in other clinical characteristics (e.g., smoking habit, thrombophilia predisposition), as well as functional and hemodynamic parameters (e.g., 6-min walk test, right heart catheterization). During three years of follow-up, no patients in the PEA groups died; conversely, eleven patients in the MT group died during the same period (p < 0.05). Furthermore, a significant decrease in plasma BNP values and an increase in a meter at the six-minute walk test, 1 and 3 years after surgery, were observed in the PEA group (p < 0.05). Conclusions: This study seems to confirm that pulmonary endarterectomy (PEA) can provide an improvement in functional tests in CTEPH.

Association of residual pulmonary hypertension with survival after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

This study investigated whether residual pulmonary hypertension (PH), defined as early postoperative mean pulmonary artery pressure (mPAP) of ≥30 mmHg, after undergoing pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) was associated with long‐term survival. All patients who underwent PEA for CTEPH at two Scandinavian centers were included in this study. Baseline characteristics and vital statuses were obtained from patient charts and national health‐data registers. The patients were then categorized based on residual PH measured via right heart catheterization within 48 h after undergoing PEA. Crude and weighted flexible parametric survival models were used to estimate the association between residual PH and all‐cause mortality and to quantify absolute survival differences. From 1992 to 2020, 444 patients underwent surgery. We excluded 6 patients who died on the day of surgery and 12 patients whose early postoperative pulmonary hemodynamic data was unavailable. Of the total study population (n = 426), 174 (41%) and 252 (59%) patients had an early postoperative mPAP <30 and ≥30 mmHg, respectively. After weighting, there was a significant association between residual PH and all‐cause mortality (hazard ratio: 2.49; 95% confidence interval [CI]: 1.60–3.87), and the absolute survival difference between the groups at 10 and 20 years was –22% (95% CI: –32% to –12%) and–32% (95% CI: –47% to –18%), respectively. A strong and clinically relevant association of residual PH with long‐term survival after PEA for CTEPH was found. After accounting for differences in baseline characteristics, the absolute survival difference at long‐term follow‐up was clinically meaningful and imply careful surveillance to improve clinical outcomes in these patients. Early postoperative right heart catheter measurements of mPAP seem to be helpful for prognostication following PEA for CTEPH.

Heart-Rate Recovery at 1 Min After Exercise Predicts Response to Balloon Pulmonary Angioplasty in Patients With Inoperable Chronic Thromboembolic Pulmonary Hypertension

Background

Dysfunction of autonomic nervous system plays an important role in the development of pulmonary hypertension. The present study aimed to investigate the interaction between balloon pulmonary angioplasty (BPA) and cardiac autonomic function by using heart-rate recovery at 1 min (HRR1) after exercise as a surrogate marker.

Methods and Results

We retrospectively enrolled 89 consecutive patients with inoperable chronic thromboembolic pulmonary hypertension who underwent BPA from May, 2018 to Jan, 2021. According to hemodynamics at follow-up, patients were categorized as BPA responders if they met one or both of the following criteria: (1) mean pulmonary arterial pressure ≤ 30 mmHg and (2) a reduction of pulmonary vascular resistance ≥ 30%. Compared with baseline, HRR1 tended to increase within 7 days after the first BPA session, and this improvement persisted at follow-up. HRR1 at baseline and at follow-up were associated with well-validated markers of CTEPH severity, including N-terminal pro-brain natriuretic peptide, mean pulmonary arterial pressure and pulmonary vascular resistance. Furthermore, the change of HRR1 from baseline to follow-up was also associated with the change of those variables. After adjustment for confounders, baseline HRR1 was still a strong independent predictor of BPA outcome. Receiver operator characteristic curve analysis showed that the cutoff value for HRR1 in predicting BPA outcome was 19 beats.

Conclusions

BPA could significantly improve HRR1, suggesting the alleviation of sympathovagal imbalance. Easily available and non-invasive HRR1 seems to be a useful tool in predicting outcome of BPA and dynamically monitoring the efficacy of BPA.

Predictors of early response to balloon pulmonary angioplasty in patients with inoperable chronic thromboembolic pulmonary hypertension

Background:

To achieve favorable hemodynamics, the number of balloon pulmonary angioplasty (BPA) sessions varied significantly among patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Increased BPA sessions burdened patients financially and psychologically. We aim to identify baseline characteristics that could predict early BPA response.

Methods:

Consecutive patients who were diagnosed with inoperable CTEPH and received BPA between May 2018 and October 2021 at Fuwai Hospital were retrospectively collected. Patients were categorized into ‘Early BPA responders’ or ‘Non-early BPA responders’ according to the hemodynamic outcome within the first three BPA sessions.

Results:

In total, 101 patients were included into analysis. At baseline, non-early BPA responders had lower female proportion, longer disease duration, and poorer laboratory test results compared with early responders, whereas hemodynamics were comparable. After the first three BPA sessions, hemodynamic improvement was more significant in early responders. Incidence of complication was comparable between the two groups. Multivariable logistic analysis identified that female sex (odds ratio [OR]: 7.155, 95% confidence interval [CI]: 1.323-38.692, p = 0.022), disease duration (OR: 0.851, 95% CI: 0.727-0.995, p = 0.043), baseline total bilirubin (OR: 0.934, 95% CI: 0.875-0.996, p = 0.038), and baseline NT-proBNP (OR: 0.473, 95% CI: 0.255-0.879, p = 0.018) were independently associated with early BPA response. Combination of these four parameters could predict 90% early BPA response.

Conclusions:

Patients with shorter disease duration, female sex, lower baseline NT-proBNP, and lower baseline total bilirubin are more likely to achieve early hemodynamic response to BPA. Moreover, early hemodynamic response was not accompanied with increased incidence of procedure-related complications.