What is the treatment approach for Chronic Thromboembolic Pulmonary Hypertension (CTEPH)?

Treatment Approach for Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

Pulmonary endarterectomy (PEA) is the treatment of choice for CTEPH as it is potentially curative and should be considered for all patients with surgically accessible disease. 1, 2

Diagnostic Evaluation

• Any patient with unexplained pulmonary hypertension should be evaluated for CTEPH, especially those with a history of venous thromboembolism 3
• Ventilation/perfusion (V/Q) scanning is the recommended initial screening test - a normal V/Q scan effectively rules out CTEPH 3, 4
• When V/Q scan shows perfusion defects or is indeterminate, CT pulmonary angiography is indicated, though a normal CT does not exclude operable CTEPH 3
• Patients with suspected CTEPH should be referred to centers with expertise in CTEPH management for definitive diagnosis and treatment planning 3, 1
• Final diagnosis requires right heart catheterization showing pre-capillary pulmonary hypertension (mean PAP ≥25 mmHg, PWP ≤15 mmHg, PVR >2 Wood units) and pulmonary angiography demonstrating organized thromboembolic occlusions 3

Treatment Algorithm

First-Line Treatment: Pulmonary Endarterectomy (PEA)

• PEA is the gold standard treatment with potential for cure 1, 2
• All CTEPH patients should be assessed for PEA eligibility by an experienced multidisciplinary team 3
• Operability depends on:
  • Location and accessibility of thrombi (main, lobar, segmental vessels are most suitable) 1
  • Patient comorbidities 1
  • Surgical expertise (experienced centers can address more distal disease) 2, 5
• There is no absolute pulmonary vascular resistance threshold or degree of right ventricular dysfunction that precludes surgery 3, 1
• In-hospital mortality is as low as 4.7% at experienced centers, with 6-year survival rates of 75-92% 3, 1

Treatment for Inoperable CTEPH

For patients deemed inoperable or with persistent/recurrent pulmonary hypertension after PEA:

1. Balloon Pulmonary Angioplasty (BPA)

   • Recommended for patients with technically inoperable disease due to distal lesions 1, 6
   • Particularly effective for subsegmental disease not accessible by surgery 5
   • Procedure-related mortality is <1% in expert centers 6

2. Medical Therapy

   • Riociguat is the only FDA-approved medication specifically for inoperable CTEPH or persistent/recurrent PH after PEA 3, 7
   • Riociguat has demonstrated improvements in exercise capacity (6-minute walking distance) and pulmonary vascular resistance 3
   • Other pulmonary arterial hypertension medications may be considered on an individual basis 3

3. Lung Transplantation

   • May be considered for advanced cases unsuitable for other interventions 1
   • Reserved for patients who fail to respond to other treatment modalities 6

Adjunctive Treatments for All CTEPH Patients

• Lifelong anticoagulation is mandatory for all CTEPH patients, typically with vitamin K antagonists targeted to an INR of 2.0-3.0 3, 1
• Supportive care with diuretics and oxygen therapy should be provided for symptoms of heart failure or hypoxemia 1

Multimodal Approach

• Combination treatments may be appropriate in selected cases 2, 6
• Options include:
  • Medical therapy as a bridge to PEA for high-risk patients 2
  • BPA for residual disease after PEA 5
  • Combined medical therapy and BPA for inoperable patients 6

Common Pitfalls

• Delayed diagnosis due to nonspecific symptoms and lack of screening 7
• Premature determination of inoperability without evaluation at an experienced CTEPH center 1
• Failure to recognize that approximately 40% of patients with CTEPH have no history of acute pulmonary embolism 4, 7
• Underestimation of surgical possibilities - experienced centers can successfully operate on patients with more distal disease who might be deemed inoperable elsewhere 2, 5