Pulmonary Artery Elastic Properties After Balloon Pulmonary Angioplasty in Patients With Inoperable Chronic Thromboembolic Pulmonary Hypertension

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.

Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension: a clinical consensus statement of the ESC working group on pulmonary circulation and right ventricular function

The current treatment algorithm for chronic thromboembolic pulmonary hypertension (CTEPH) as depicted in the 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines on the diagnosis and treatment of pulmonary hypertension (PH) includes a multimodal approach of combinations of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and medical therapies to target major vessel pulmonary vascular lesions, and microvasculopathy. Today, BPA of >1700 patients has been reported in the literature from centers in Asia, the US, and also Europe; many more patients have been treated outside literature reports. As BPA becomes part of routine care of patients with CTEPH, benchmarks for safe and effective care delivery become increasingly important. In light of this development, the ESC Working Group on Pulmonary Circulation and Right Ventricular Function has decided to publish a document that helps standardize BPA to meet the need of uniformity in patient selection, procedural planning, technical approach, materials and devices, treatment goals, complications including their management, and patient follow-up, thus complementing the guidelines. Delphi methodology was utilized for statements that were not evidence based. First, an anatomical nomenclature and a description of vascular lesions are provided. Second, treatment goals and definitions of complete BPA are outlined. Third, definitions of complications are presented which may be the basis for a standardized reporting in studies involving BPA. The document is intended to serve as a companion to the official ESC/ERS guidelines.

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.

Changes in Inflammatory Markers in Patients with Chronic Thromboembolic Pulmonary Hypertension Treated with Balloon Pulmonary Angioplasty

Background: Inflammatory response and endothelial dysfunction contribute to the progression of chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to assess changes in biomarkers involved in those processes in inoperable CTEPH patients treated with balloon pulmonary angioplasty (BPA). Methods: We enrolled 20 patients with inoperable CTEPH qualified for BPA and a control group. Interleukin 6, 8, 10 (IL-6, IL-8, IL-10), monocyte chemoattractant protein-1 (MCP-1), and C-reactive protein (hsCRP) constituted the markers of systemic inflammation. Endothelin 1 (ET-1) served as a marker of endothelial dysfunction. Selected markers were assessed before the BPA treatment, 24 h after the first BPA, and six months after completion of the BPA treatment. Results: At baseline, the CTEPH patients had increased serum concentrations of IL-6, IL-8 and ET-1. Twenty-four hours after a BPA session, we observed an increase in concentrations of IL-6 (∆ = 3.67 (1.41; 7.16); p < 0.001), of IL-10 (∆ = 0.25 (0; 0.47); p = 0.003), of MCP-1 (∆ = 111 (60.1; 202.8); p = 0.002), and of hsCRP (∆ = 4.81 (3.46; 8.47); p < 0.001). Six months after completion of the BPA treatment, there was a decrease in concentrations of IL-6 (∆ = −1.61 (−3.11; −0.20); p = 0.03), of IL8 (∆ = −3.24 (−7.72; 0.82); p = 0.01), and of ET-1 (∆ = −0.47 (−0.96; 0.05); p = 0.005). Conclusions: Patients with inoperable CTEPH exhibit increased systemic inflammation and endothelial dysfunction, which improves after completion of the BPA treatment. A single BPA session evokes an acute inflammatory response.

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.

Change in pulmonary arterial compliance and pulmonary pulsatile stress after balloon pulmonary angioplasty

OBJECTIVE

Although the underlying pathology of chronic thromboembolic pulmonary hypertension (CTEPH) is mechanical obliteration of the major pulmonary vessels, high pulsatile stress penetrating into the normal distal pulmonary microvasculature resulting from reduced pulmonary arterial compliance (CPA) may cause progressive deterioration in pulmonary hemodynamics. Hypothetically, balloon pulmonary angioplasty (BPA) may be beneficial in reducing CPA and pulsatile stress in patients with CTEPH.

METHODS

In total, 26 patients with available pre- and post-BPA right heart catheterization results were included in the study. BPA was performed in a series of staged procedures by 2 experienced interventional cardiologists.

RESULTS

The median CPA showed a 59.2% increase (1.03 to 1.64 mL/mm Hg, p=0.005). The median pre-BPA pulsatile stress product decreased by 20.7% (4,266 to 3,380 mm Hg/min, p=0.003). A linear regression model established that the percent change in CPA after BPA accounted for 21.8% of the explained variability in the change in 6-minute walk test (p=0.009).

CONCLUSION

Our results indicate that BPA decreases CPA and pulmonary pulsatile stress. These changes may be partly responsible for the improvement in functional capacity after BPA.

Interventional Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension is a distinct form of pulmonary hypertension characterized by the nonresolution of thrombotic material in the pulmonary tree; whenever feasible and safe, first-line treatment should be pulmonary thromboendarterectomy. In patients who are not operative candidates, balloon pulmonary angioplasty (BPA) has emerged as an effective treatment modality that results in improvements in functional class, symptoms, hemodynamics, 6-minute walk distance, and right ventricular and pulmonary artery mechanics. Careful attention to procedural technique and rapid identification and treatment of complications are critical for a successful BPA program.

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.

Characteristics and outcomes of patients with chronic thromboembolic pulmonary hypertension in the era of modern therapeutic approaches: data from the Polish multicenter registry (BNP-PL)

Background:

Significant achievements in the treatment of chronic thromboembolic pulmonary hypertension (CTEPH) have provided effective therapeutic options for most patients. However, the true impact of the changed landscape of CTEPH therapies on patients’ management and outcomes is poorly known. We aimed to characterize the incidence, clinical characteristics, and outcomes of CTEPH patients in the modern era of CTEPH therapies.

Methods:

We analyzed the data of CTEPH adults enrolled in the prospective multicenter registry.

Results:

We enrolled 516 patients aged 63.8 ± 15.4 years. The incidence rate of CTEPH was 3.96 per million adults per year. The group was burdened with several comorbidities. New oral anticoagulants (n = 301; 58.3%) were preferred over vitamin K antagonists (n = 159; 30.8%). Pulmonary endarterectomy (PEA) was performed in 120 (23.3%) patients and balloon pulmonary angioplasty (BPA) in 258 (50%) patients. PEA was pretreated with targeted pharmacotherapy in 19 (15.8%) patients, and BPA in 124 (48.1%) patients. Persistent CTEPH was present in 46% of PEA patients and in 65% of patients after completion of BPA. Persistent CTEPH after PEA was treated with targeted pharmacotherapy in 72% and with BPA in 27.7% of patients. At a mean time period of 14.3 ± 5.8 months, 26 patients had died. The use of PEA or BPA was associated with better survival than the use of solely medical treatment.

Conclusions:

The modern population of CTEPH patients comprises mostly elderly people significantly burdened with comorbid conditions. This calls for treatment decisions that are tailored individually for every patient. The combination of two or three methods is currently a frequent approach in the treatment of CTEPH.

Clinical Trial Registration:

clinicaltrials.gov/ct2/show/NCT03959748

Balloon Pulmonary Angioplasty: State of the Art

Balloon pulmonary angioplasty (BPA) is a novel technique for the treatment of chronic thromboembolic pulmonary hypertension. While cardiologists need no introduction to the concept of balloon angioplasty, BPA has its own particular challenges. This article aims to provide the reader with an overview of BPA, starting with an introduction to chronic thromboembolic disease (CTED), the standard management of chronic thromboembolic pulmonary hypertension (CTEPH), technical challenges faced when performing BPA and the evidence base supporting its use. The second part of the article will focus on the future of BPA, in particular the areas where research is required to establish an evidence base to justify the role of BPA in CTEPH and CTED treatment.

Hemodynamic Effects of Ultrasound-Assisted, Catheter-Directed, Very Low-Dose, Short-Time Duration Thrombolysis in Acute Intermediate-High Risk Pulmonary Embolism (from the EKOS-PL Study)

Ultrasound-assisted, catheter-directed, low-dose thrombolysis (USAT) at an average alteplase dose of 20 mg infused over 12 to 24 hours reversed right ventricular disfunction and improved pulmonary hemodynamics in intermediate-high-risk pulmonary embolism patients. As bleeding risk increases with the thrombolytic dose, establishing a minimal effective USAT dosing regimen is of clinical importance. We aimed to investigate hemodynamic effects and safety of a very low-alteplase-dose USAT of 10 mg administered within 5 hours. We included 12 consecutive intermediate-high-risk pulmonary embolism patients with symptoms duration of <14 days and proximal thrombi location in pulmonary arteries. Pulmonary Embolism Response Team decision-based fixed, bilateral ultrasound-assisted alteplase infusions at the rate of 1mg/hour/catheter for 5 hours through EKOS system catheters were made. The primary efficacy measure was the change in invasive systolic and mean pulmonary arteries pressure, and in cardiac index from USAT start to termination. Safety measures were 180-day all-cause death or cardiopulmonary decompensation and bleeding complications. The systolic pulmonary arteries pressure and mean pulmonary arteries pressure decreased from 53 (45.5 to 59) to 37.5 (27.5 to 40.5) mm Hg (p = 0.02) and from 29.5 (27.5 to 32) to 21.5 (15.5 to 25) mm Hg (p = 0.02), respectively. The cardiac index increased from 1.6 (1.5 to 1.8) to 2.2 (1.9 to 2.4) l/min/m², (p = 0.02). No deaths, decompensations, or need for therapy intensification occurred. There was 1 episode of access-site bleeding, which subsided after conservative management. No intracranial hemorrhages appeared. In conclusion, reduced dose and duration USAT improved pulmonary hemodynamics and cardiac function leading to cardiopulmonary stabilization in intermediate-high risk pulmonary embolism patients at a low periprocedural risk.

Virtual Histology to Evaluate Mechanisms of Pulmonary Artery Lumen Enlargement in Response to Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) results from an obstruction of pulmonary arteries (PAs) by organized thrombi. The stenosed PAs are targeted during balloon pulmonary angioplasty (BPA). We aimed to evaluate the mechanism of BPA in inoperable patients with CTEPH. We analyzed stenosed PAs with intravascular grey-scale ultrasound (IVUS) to determine the cross-sectional area (CSA) of arterial lumen and of organized thrombi. The composition of organized thrombi was assessed using virtual histology. We distinguished two mechanisms of BPA: Type A with dominant vessel stretching, and type B with dominant thrombus compression. PAs were assessed before (n = 159) and after (n = 98) BPA in 20 consecutive patients. Organized thrombi were composed of dark-green (57.1 (48.0–64.0)%), light-green (34.0 (21.4–46.4)%), red (6.4 (2.9–11.7)%;) and white (0.2 (0.0–0.9)%) components. The mechanism type depended on vessel diameter (OR = 1.09(1.01–1.17); p = 0.03). In type B mechanism, decrease in the amount of light-green component positively correlated with an increase in lumen area after BPA (r = 0.50; p = 0.001). The mechanism of BPA depends on the diameter of the vessel. Dilation of more proximal PAs depends mainly on stretching of the vessel wall while dilation of smaller PAs depends on compression of the organized thrombi. The composition of the organized thrombi contributes to the effect of BPA.

Pregnancy in a Patient With Chronic Thromboembolic Pulmonary Hypertension After Successful Treatment with Balloon Pulmonary Angioplasty

Pulmonary hypertension has been recognized as a contraindication to pregnancy. Recently, several groups have shown promising results with the use of balloon pulmonary angioplasty (BPA) in the treatment of chronic thromboembolic pulmonary hypertension (CTEPH) patients with distally located organized thrombi who were not candidates for pulmonary endarterectomy. We present the case report of a 26-year-old woman who became pregnant after successful treatment of severe CTEPH with the use of BPA. We conclude that patients undergoing effective BPA for CTEPH can consider becoming pregnant if followed closely by a multidisciplinary team, including experts in thrombosis, pulmonary hypertension, and obstetrics.