Balloon pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension: is Europe behind?

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: Clinical Outcomes

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare major vessel pulmonary vascular disease that is characterised by fibrotic obstructions deriving from an organised clot. Recent advances in treatments for CTEPH have significantly improved outcomes. Apart from classical surgical pulmonary endarterectomy, balloon pulmonary angioplasty (BPA) and vasodilator drugs that were tested in randomised controlled trials of non-operable patients are now available. In Europe, CTEPH affects males and females equally. In the first European CTEPH Registry, women with CTEPH underwent pulmonary endarterectomy less frequently than men, especially at low-volume centres. In Japan, CTEPH is more common in females and is predominantly treated by BPA. More data on gender-specific outcomes are expected from the results of the International BPA Registry (NCT03245268).

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.

Pulmonary Hypertension Definition, Classification, and Epidemiology in Asia

Pulmonary hypertension (PH) is caused by a range of conditions and is important to recognize as it is associated with increased mortality. Pulmonary arterial hypertension refers to a group of PH subtypes affecting the distal pulmonary arteries for which effective treatment is available. The hemodynamic definition of pulmonary arterial hypertension has recently changed which may lead to greater case recognition and earlier treatment. The prevalence of specific PH etiologies may differ depending on geographic region. PH caused by left heart disease is the most common cause of PH worldwide. In Asia, there is greater proportion of congenital heart disease- and connective tissue disease- (especially systemic lupus erythematosus) related PH relative to the West. This review summarizes the definition, classification, and epidemiology of PH as it pertains to Asia.

Balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension: a multicentre registry

BACKGROUND

Balloon pulmonary angioplasty (BPA) is a promising therapy for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are ineligible for pulmonary endarterectomy.

AIMS

The present study aimed to evaluate the safety and efficacy of BPA for CTEPH using the first multicentre registry of a single European country.

METHODS

Data were obtained from the Database of Pulmonary Hypertension in the Polish Population (NCT03959748), a prospective, multicentre registry of adult and paediatric pulmonary arterial hypertension (PAH) and CTEPH, for a total of 236 patients with confirmed CTEPH (124 women; mean age 67 years) who underwent 1,056 BPA procedures at eight institutions in Poland.

RESULTS

In 156 patients who underwent follow-up assessments after a median of 5.9 (IQR: 3.0-8.0) months after final BPA, the mean pulmonary arterial pressure decreased from 45.1±10.7 to 30.2±10.2 mmHg (p<0.001) and pulmonary vascular resistance from 642±341 to 324±183 dynes (p<0.001), and the six-minute walking test (6MWT) improved from 341±129 to 423±136 m (p<0.001). Pulmonary injury related to the BPA procedure occurred in 6.4% of all sessions. Eighteen patients (7.6%) died during follow-up, including 4 (1.7%) who died within 30 days after BPA. Overall survival was 92.4% (95% confidence interval [CI]: 87.6%-94.9%) three years after the initial BPA procedure.

CONCLUSIONS

This multicentre registry confirmed significant improvement of haemodynamic, functional, and biochemical parameters after BPA. Complication rates were low and overall survival comparable to the results of another registry. Therefore, BPA may be an important therapeutic option in patients with CTEPH in Poland.

Safety and efficacy of balloon pulmonary angioplasty in a Portuguese pulmonary hypertension expert center

INTRODUCTION

Balloon pulmonary angioplasty (BPA) is an alternative therapy in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or residual/recurrent pulmonary hypertension (PH) after surgery. The aim of this study was to assess the short-term efficacy and safety of a BPA program.

METHODS

This prospective single-center study included all BPA sessions performed in CTEPH patients between 2017 and 2019. Clinical assessment including WHO functional class, plasma biomarkers, 6-min walk test (6MWT) and right heart catheterization was performed at baseline and six months after the last BPA session.

RESULTS

A total of 57 BPA sessions were performed in 11 CTEPH patients (64% with inoperable disease, 82% under pulmonar vasodilator therapy). Nine patients completed both the BPA program and a minimum six-month follow-up period. There were significant improvements in WHO functional class (p=0.004) and 6MWT (mean increase of 42 m; p=0.050) and a trend for significant hemodynamic improvement: 25% decrease in mean pulmonary artery pressure (mPAP) (p=0.082) and 42% decrease in pulmonary vascular resistance (PVR) (p=0.056). In the group of patients with severely impaired hemodynamics (three patients with mPAP >40 mmHg), the reduction was significant: 51% in mPAP (p=0.013) and 67% in PVR (p=0.050). Prostacyclin analogs and long-term oxygen therapy were withdrawn in all patients. Minor complications were recorded in 25% of patients. There were no major complications or deaths.

CONCLUSIONS

A BPA strategy on top of pulmonary vasodilator therapy further improves symptoms, exercise capacity and hemodynamics with an acceptable risk-benefit ratio in patients with inoperable CTEPH or residual/recurrent PH after surgery.

Safety and efficacy of balloon pulmonary angioplasty in a Portuguese pulmonary hypertension expert center

INTRODUCTION

Balloon pulmonary angioplasty (BPA) is an alternative therapy in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or residual/recurrent pulmonary hypertension (PH) after surgery. The aim of this study was to assess the short-term efficacy and safety of a BPA program.

METHODS

This prospective single-center study included all BPA sessions performed in CTEPH patients between 2017 and 2019. Clinical assessment including WHO functional class, plasma biomarkers, 6-min walk test (6MWT) and right heart catheterization was performed at baseline and six months after the last BPA session.

RESULTS

A total of 57 BPA sessions were performed in 11 CTEPH patients (64% with inoperable disease, 82% under pulmonary vasodilator therapy). Nine patients completed both the BPA program and a minimum six-month follow-up period. There were significant improvements in WHO functional class (p=0.004) and 6MWT (mean increase of 42 m; p=0.050) and a trend for significant hemodynamic improvement: 25% decrease in mean pulmonary artery pressure (mPAP) (p=0.082) and 42% decrease in pulmonary vascular resistance (PVR) (p=0.056). In the group of patients with severely impaired hemodynamics (three patients with mPAP >40mmHg), the reduction was significant: 51% in mPAP (p=0.013) and 67% in PVR (p=0.050). Prostacyclin analogs and long-term oxygen therapy were withdrawn in all patients. Minor complications were recorded in 25% of patients. There were no major complications or deaths.

CONCLUSIONS

A BPA strategy on top of pulmonary vasodilator therapy further improves symptoms, exercise capacity and hemodynamics with an acceptable risk-benefit ratio in patients with inoperable CTEPH or residual/recurrent PH after surgery.

Risk stratification in patients with residual pulmonary hypertension after pulmonary endarterectomy

BACKGROUND

Few studies addressed the issue of risk stratification in patients with residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). This study tested the potential added value of parameters that have not been included in existing risk models.

METHODS

We evaluated 546 consecutive patients with chronic thromboembolic pulmonary hypertension who underwent PEA and were followed-up for a median period of 58 months.

RESULTS

Among the 242 with residual PH, 27 died and had 127 a clinical worsening event. At univariable analysis, the parameters associated with poor survival were pulmonary vascular resistance (PVR) ≥425 dyn·s·cm^-5 (p ≤ 0.001), mean pulmonary artery pressure (mPAP) ≥38 mmHg (p = 0.003) and pulmonary artery compliance (CPA) ≤1.8 ml/mmHg (p = 0.014). In the bivariable models including either PVR or mPAP as first parameter, the addition of CPA was not statistically significant. The parameters associated with poor clinical worsening were CPA ≤1.8 ml/mmHg (p < 0.001), PVR ≥425 dyn·s·cm^-5 (p = 0.002), arterial oxygen tension (PaO2) ≤ 75 mmHg (p = 0.003), mPAP ≥38 mmHg (p = 0.008). In a multivariable analysis which included PVR ≥425 as the first parameter, the addition of both CPA ≤1.8 ml/mmHg and of PaO2 ≤ 75 mmHg significantly improved prognostic stratification (Harrel's C of the model = 0.64, p < 0.001). Noticeably, the lower tertile of the model's predictor index identified a subgroup of 91 patients who had an event rate numerically similar to that of patients without residual PH.

CONCLUSIONS

Risk stratification in residual PH can be refined if CPA and PaO2 are considered in association with standard hemodynamic parameters.

Balloon Pulmonary Angioplasty in Technically Operable and Technically Inoperable Chronic Thromboembolic Pulmonary Hypertension

Background: In this study, we aimed to assess the efficacy and safety of balloon pulmonary angioplasty (BPA) in patients with technically inoperable distal-type chronic thromboembolic pulmonary hypertension (d-CTEPH) and technically operable proximal-type disease (p-CTEPH) by analyzing the results of BPA treatment in two collaborating CTEPH referral centers. Methods and results: We assessed hemodynamic results, functional efficacy, complication and survival rate after BPA treatment in 70 CTEPH patients (median age 64 years; (interquartile range (IQR): 52–73 years)), of whom 16 (median age 73 years; (QR 62–82 years)) were in the p-CTEPH subgroup. Altogether, 377 BPA procedures were performed, resulting in significant (p < 0.001) improvement in mean pulmonary artery pressure (mPAP 48.6 ± 10 vs. 31.3 ± 8.6 mmHg), pulmonary vascular resistance (694 ± 296 vs. 333 ± 162 dynes*s*cm⁻⁵), six-minute walk test (365 ± 142 vs. 433 ± 120 metres) and N-terminal pro B-type natriuretic peptide (1307 (510–3294) vs. 206 (83–531) pg/mL). The rate of improvement did not differ between the sub-groups. Lung injury episodes and severe hemoptysis were similarly infrequent in d-CTEPH and p-CTEPH (6.4% vs. 5%; p = 0.55 and 1.0% vs. 2.5; p = 0.24, respectively). There was no significant difference between the sub-groups regarding survival (p = 0.53 by log-rank test). Conclusion: BPA may be beneficial in patients with p-CTEPH who cannot undergo pulmonary endarterectomy (PEA). Larger long-term studies are needed to better define the efficacy, safety, and optimal BPA procedural standards in this population.

Novel Balloon Pulmonary Angioplasty Technique for Chronic Thromboembolic Pulmonary Hypertension

This study aimed to clarify the usefulness of the Ikari-curve left (IL) guiding catheter for balloon pulmonary angioplasty (BPA).The current BPA strategy for chronic thromboembolic pulmonary hypertension is dilation of as many branches as possible to normalize hemodynamics and oxygenation. The shape of the guiding catheter is a major factor in achieving this. However, conventional guiding catheters are difficult to introduce into particular branches. The IL guiding catheter may be suitable; however, its utility remains unclear.We retrospectively analyzed 202 consecutive BPA sessions of 40 patients from November 2016 to October 2019 and divided these sessions into two groups: the IL group where the IL guiding catheter was used and the non-IL group where other catheters were utilized. The occurrence of lung injury was determined by the presence of bloody sputum. We compared the rates of successful introduction into target vessels and assessed for the occurrence of lung injury.The average age of enrolled patients was 60.3 ± 14.4 years, with females comprising 65%. There were 99 sessions in the IL group. The median treated branches per session differed between the 2 groups (IL group: 15 versus non-IL group: 10, P < 0.05). The occurrence of lung injury was lower in the IL group (4.0% versus 11.7%, P = 0.07). The IL group had more successful vessel insertions than the non-IL group (78.8% versus 42.7%, P < 0.01).The IL guiding catheter may be introduced into branches that cannot be accessed by conventional guiding catheters.

Safety and efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension in the Netherlands

Background

Balloon pulmonary angioplasty (BPA) is an emerging treatment in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic disease (CTED). We describe the first safety and efficacy results of BPA in the Netherlands.

Methods

We selected all consecutive patients with inoperable CTEPH and CTED accepted for BPA treatment who had a six-month follow-up in the St. Antonius Hospital in Nieuwegein and the Amsterdam University Medical Center (UMC) in Amsterdam. Functional class (FC), N‑terminal pro-brain natriuretic peptide (NT-proBNP), 6‑minute walking test distance (6MWD) and right-sided heart catheterisation were performed at baseline and six months after last BPA. Complications for each BPA procedure were noted.

Results

A hundred and seventy-two BPA procedures were performed in 38 patients (61% female, mean age 65 ± 15 years). Significant improvements six months after BPA treatment were observed for functional class (63% FC I/II to 90% FC I/II, p = 0.014), mean pulmonary artery pressure (−8.9 mm Hg, p = 0.0001), pulmonary vascular resistance (−2.8 Woods Units (WU), p = 0.0001), right atrial pressure (−2.0 mm Hg, p = 0.006), stroke volume index (+5.7 ml/m², p = 0.009) and 6MWD (+48m, p = 0.007). Non-severe complications occurred in 20 (12%) procedures.

Conclusions

BPA performed in a CTEPH expert centre is an effective and safe treatment in patients with inoperable CTEPH.