Balloon Pulmonary Angioplasty (BPA)

Definition

Balloon pulmonary angioplasty (BPA) is a percutaneous catheter-based procedure in which undersized balloons are used to dilate obstructed pulmonary arterial branches caused by chronic thromboembolic disease. It is indicated for patients with CTEPH who are inoperable or have residual PH after pulmonary endarterectomy (PEA). BPA received a Class I recommendation from the 2022 ESC/ERS guidelines for inoperable and residual CTEPH, supported by two landmark RCTs (RACE and MR BPA).

Key Concepts

Guideline Status

• ESC 2022 Class I recommendation for BPA in technically inoperable CTEPH and residual CTEPH after PEA — upgraded from Class IIb (2015). (sources/BPA-AHA-2024, rating: very high; sources/PHT-ESC-2022, rating: very high)
• Upgrade was based on RACE trial (BPA vs riociguat) and MR BPA trial, both showing BPA achieved significantly greater reduction in PVR than riociguat alone in inoperable distal CTEPH with PVR >4 WU. (sources/BPA-AHA-2024, rating: very high)
• RACE trial also supports riociguat as pretreatment before BPA in patients with PVR >4 WU. (sources/BPA-AHA-2024, rating: very high)
• Expert centre designation requires ≥30 patients/year undergoing BPA or >100 BPA procedures and >50 PEA surgeries/year (ESC/ERS criteria). (sources/BPA-AHA-2024, rating: very high)

Patient Selection

• BPA is preferred over PEA for: isolated level 4 (subsegmental) disease; high surgical risk (multiple comorbidities); residual CTEPH after PEA; patients declining surgery. (sources/BPA-AHA-2024, rating: very high)
• PEA is preferred for level 1–3 accessible disease in patients with proportionate haemodynamic impairment and acceptable surgical risk. (sources/BPA-AHA-2024, rating: very high)
• Multidisciplinary team essential: must include imaging expertise, PEA surgeon, BPA interventionalist, and CTEPH medical management expertise — missing one component biases treatment to local availability. (sources/BPA-AHA-2024, rating: very high)
• BPA in CTEPD without resting PH: Exercise RHC and invasive CPET can phenotype dyspnoea aetiology; limited data support benefit but optimal patient selection criteria remain undefined. (sources/BPA-AHA-2024, rating: very high)
• BPA in mild CTEPH (mPAP >20, PVR >2 WU): Asymptomatic patients generally do not require intervention; symptomatic patients may derive benefit but medical therapy + follow-up is also acceptable. (sources/BPA-AHA-2024, rating: very high)
• CKD: BPA is safe; limit contrast to ≤3× baseline GFR. (sources/BPA-AHA-2024, rating: very high)

Anatomical Disease Level Classification

Disease level on NS-iPA governs treatment selection:

• Level 1: Main pulmonary artery — surgically accessible; PEA preferred
• Level 2: Lobar pulmonary artery — surgically accessible; PEA preferred
• Level 3: Segmental pulmonary artery — surgically accessible at most expert centres; zone of expert disagreement for mid-to-distal segmental disease
• Level 4: Subsegmental pulmonary artery — Class I indication for BPA per ESC 2022 (sources/BPA-AHA-2024, rating: very high)

BPA Lesion Classification (Kawakami et al.)

• Type 1: Ring lesions — standard risk
• Type 2: Web lesions — standard risk
• Type 3: Subtotal occlusions — higher risk; more frequent complications
• Type 4: Total occlusions — higher risk; more frequent complications
• Type 5: Diffusely tortuous vessels distal to subsegmental branches — highest risk; vascular complications >40%; BPA should be avoided (sources/BPA-AHA-2024, rating: very high)

Angiographic Best Practices

• NS-iPA: two runs per lung in orthogonal projections during deep inspiratory breath hold with digital subtraction. Oblique projections preferred over frontal/lateral as BPA road maps (lower radiation). Biplane angiography reduces contrast and radiation. (sources/BPA-AHA-2024, rating: very high)
• S-iPA: lesion severity assessed in orthogonal views — asymmetric stenoses may be missed in single projection. Guide extension catheters allow deep coaxial engagement with reduced contrast. (sources/BPA-AHA-2024, rating: very high)

Procedural Technique

• Angiographically patent vessels with abnormal venous return: measure resting pressure gradient; dilate until brisk venous return or Pd:Pa >0.80. (sources/BPA-AHA-2024, rating: very high)
• Pd:Pa >0.80 threshold is empirical; not yet validated in powered studies. (sources/BPA-AHA-2024, rating: very high)
• Failure to restore venous return despite 1:1 balloon sizing + Pd:Pa >0.80 = underlying pulmonary arteriopathy → manage with pulmonary vasodilators. (sources/BPA-AHA-2024, rating: very high)
• Wire choice: nonhydrophilic soft-tip (<1 g tip load) 0.014-in coronary wire with J-shaped distal tip — minimises respiratory motion-related vessel perforation and hemoptysis. (sources/BPA-AHA-2024, rating: very high)
• Perform BPA in one lung per session; 4–8 sessions typically required for complete revascularisation. (sources/BPA-AHA-2024, rating: very high)
• Sequential sessions: chronically occluded subsegmental arteries remodel between sessions, allowing progressively larger balloon dilatation. (sources/BPA-AHA-2024, rating: very high)

Post-procedural Care and Follow-up

• Intravenous heparin after hemostasis; inpatient monitoring 24–48 hours standard.
• RHC 3–6 months after final BPA session to assess need for further BPA or adjunctive medical therapy. (sources/BPA-AHA-2024, rating: very high)
• If CPET was used for pre-BPA selection, repeat CPET 3–6 months post-BPA to assess interval changes. (sources/BPA-AHA-2024, rating: very high)
• Long-term noninvasive follow-up sufficient unless progressive symptoms or noninvasive evidence of PH recurrence. (sources/BPA-AHA-2024, rating: very high)

Complications and Safety Trends

• Meta-analysis of 26 studies (1675 patients, 7603 procedures, 4 continents): Complication rates declining significantly from 2013–2017 to 2018–2022:

(sources/BPA-AHA-2024, rating: very high)

• Declining rates attributed to: procedural refinement; better patient/lesion selection; increasing adjunctive pulmonary vasodilator use; evolving anticoagulation practices. (sources/BPA-AHA-2024, rating: very high)
• Lung injury (reperfusion pulmonary edema): most common complication; usually resolves with O₂ ± NIPPV for 2–4 hours. Risk increased by worse baseline haemodynamics and higher-risk lesion subtypes. (sources/BPA-AHA-2024, rating: very high)
• Hemoptysis: Usually scant and self-resolving. Severe hemoptysis = vascular perforation → proximal balloon tamponade → selective intubation into contralateral lung → coil/gelatin foam occlusion. (sources/BPA-AHA-2024, rating: very high)

Starting a New BPA Program

• Initiate BPA programs only within experienced CTEPH centres already offering PEA — BPA is one of several tools in a comprehensive CTEPH programme.
• Progress stepwise: early sessions should target lower-risk lesion types (ring, web) in lower-risk patients.
• Peer guidance from experienced centres is essential for reducing the learning curve. (sources/BPA-AHA-2024, rating: very high)

Key Knowledge Gaps

• No randomised data for BPA vs PEA in predominantly level 3 (mid-to-distal segmental) disease.
• Pd:Pa >0.80 threshold requires prospective validation.
• Long-term pulmonary arterial branch patency after BPA is largely unknown.
• Optimal protocols for pulmonary vasodilator weaning after effective BPA are undefined.
• Standardised endpoint definitions and complication definitions are needed to enable cross-centre registry comparisons.

Contradictions / Open Questions

• BPA vs riociguat in non-level-4 disease: Both RACE and MR BPA were conducted in distal inoperable CTEPH; neither provides guidance for BPA vs medical therapy in patients with surgically inaccessible disease without haemodynamic compromise. (sources/BPA-AHA-2024, rating: very high)
• Post-PEA BPA: Class I recommendation for BPA in residual CTEPH after PEA is supported only by observational case series — not RCTs. Hemoptysis and vessel injury rates appear higher post-PEA than in de novo distal CTEPH. (sources/BPA-AHA-2024, rating: very high)
• CTEPD without resting PH: BPA and PEA can improve symptoms and ventilatory efficiency, but the evidence is limited, and optimal patient selection criteria remain undefined. (sources/BPA-AHA-2024, rating: very high)
• Pd:Pa threshold: The empirical 0.80 target for adequate dilatation has not been validated in powered studies — this threshold may be under- or over-estimating adequate revascularisation. (sources/BPA-AHA-2024, rating: very high)

Connections

• Related to entities/CTEPH
• Related to entities/Pulmonary-Hypertension
• Related to concepts/PAH-Risk-Stratification
• Related to concepts/Right-Heart-Catheterization
• Related to concepts/Acute-PE-Clinical-Categories
• Related to sources/BPA-AHA-2024
• Related to sources/PHT-ESC-2022

Sources

• sources/BPA-AHA-2024
• sources/PHT-ESC-2022