What is the role of balloon pulmonary angioplasty (BPA) in the treatment of a patient with chronic thromboembolic pulmonary hypertension (CTEPH)?

Balloon Pulmonary Angioplasty for CTEPH

Balloon pulmonary angioplasty (BPA) should be considered for CTEPH patients who are technically inoperable or have an unfavorable risk-benefit ratio for pulmonary endarterectomy (PEA), as determined by a multidisciplinary CTEPH team that includes at least one experienced PEA surgeon. 1, 2

Treatment Hierarchy

PEA remains the first-line, potentially curative treatment for CTEPH and must always be evaluated first before considering BPA. 1, 2 The 2015 ESC/ERS guidelines assign BPA a Class IIb recommendation with Level C evidence for patients deemed technically non-operable or with unfavorable surgical risk-benefit ratio. 1, 2

Specific Indications for BPA

Primary Patient Populations

• Technically inoperable disease: Patients with distal segmental or subsegmental thromboembolic disease beyond surgical reach should be considered for BPA. 1, 2

• High surgical risk patients: Those with technically operable disease but an unfavorable risk-benefit ratio for PEA may be considered for BPA. 1, 2

• Persistent/recurrent pulmonary hypertension post-PEA: Patients with residual PH after surgical endarterectomy are candidates for BPA. 1, 2

Critical Decision-Making Requirements

All operability assessments must be performed by a multidisciplinary CTEPH team at an experienced center (Class I, Level C recommendation). 1, 2 The team must include at least one experienced PEA surgeon to ensure accurate determination of surgical candidacy. 1, 2 This is non-negotiable—proceeding with BPA without formal multidisciplinary evaluation including an experienced PEA surgeon represents a critical error in management. 2

Technical Approach and Efficacy

BPA is a stepwise procedure requiring multiple sessions (typically 4-10 separate sessions, averaging 2.7-4.6 sessions per patient). 1, 3, 4 This staged approach is necessary to engage all under-perfused lung segments while limiting contrast burden and radiation exposure per session. 1

Hemodynamic and Functional Outcomes

Recent studies demonstrate significant improvements with refined BPA techniques:

• Hemodynamic improvements: Mean pulmonary artery pressure decreases by approximately 12 mmHg, with pulmonary vascular resistance (PVR) improving by 26-246 dyn·cm·s⁻⁵. 3, 5, 4

• Functional capacity: Six-minute walk distance improves by 39-72 meters, with WHO functional class improving by one class. 3, 5, 4

• Cardiac function: Right ventricular strain markers (NT-proBNP, troponin T) significantly decrease, indicating reduced RV afterload. 3, 5

The most recent U.S. data from 2023 showed that independent factors associated with improved response included pre-procedural use of riociguat, reduced baseline PA compliance, and >3 BPA sessions per patient. 4

Safety Profile and Complications

Complication Rates with Refined Techniques

Modern refined BPA techniques have substantially reduced complication rates compared to earlier approaches. 1, 6 The most common serious complication is reperfusion pulmonary edema, which has been reduced to approximately 2% with refined techniques using smaller balloons and cautious targeting of only one lobe per session. 1

Specific Complications to Monitor

• Hemoptysis: Occurs in approximately 4.7% of sessions with refined techniques. 4
• Wire perforation, vessel dissection, or rupture: Life-threatening complications requiring meticulous technique. 6
• Reperfusion pulmonary edema: Reduced to 2% with refined approach versus higher rates (up to 61% in early series). 1, 5

Early studies reported periprocedural mortality rates of 10%, but these reflect older, less refined techniques. 5 Contemporary series with refined approaches show substantially improved safety profiles. 1, 4

Mandatory Prerequisites

Before Proceeding with BPA

• Lifelong anticoagulation: Must be established with vitamin K antagonists (VKAs) targeted to INR 2-3. 1, 2 No data exist for direct oral anticoagulants (DOACs/NOACs) in CTEPH. 1

• Comprehensive hemodynamic assessment: Right heart catheterization confirming precapillary pulmonary hypertension is required. 2

• Imaging characterization: Ventilation/perfusion scanning and pulmonary angiography to characterize disease distribution are mandatory. 2

• Center expertise: BPA should only be performed at experienced, high-volume CTEPH centers with appropriate expertise and equipment. 1, 2

Relationship with Medical Therapy

Riociguat is the only approved drug for inoperable CTEPH or persistent/recurrent PH after PEA (Class I, Level B recommendation). 1 BPA patients may still require riociguat or other pulmonary hypertension medications for optimal outcomes, and pre-procedural riociguat use is associated with better BPA response. 2, 4

Off-label use of other PAH-approved drugs may be considered in symptomatic inoperable patients (Class IIb, Level B recommendation). 1 However, medical therapy alone does not address the mechanical obstruction that BPA can treat. 1, 2

Critical Pitfalls to Avoid

• Never use BPA as first-line therapy: PEA remains superior with potential for cure and must always be considered first. 1, 2

• Never proceed without multidisciplinary evaluation: Formal assessment by a team including an experienced PEA surgeon is mandatory. 1, 2

• Avoid inexperienced centers: Complication rates are significantly higher without proper expertise, equipment, and refined techniques. 1, 2

• Do not assume operability based on hemodynamics alone: There is no absolute upper limit of PVR or degree of RV dysfunction that excludes patients from either PEA or BPA consideration at experienced centers. 1, 2

• Advanced age is not a contraindication: Age alone should not exclude patients from BPA consideration. 1, 2