What are the treatment options for CTEPH (Chronic Thromboembolic Pulmonary Hypertension)?

Treatment Options for Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

Pulmonary endarterectomy (PEA) is the treatment of choice for CTEPH as it is the only potentially curative option and should be considered for all patients with operable disease. 1

Diagnostic Approach

• A ventilation/perfusion (V/Q) lung scan is the recommended initial screening test for CTEPH in patients with unexplained pulmonary hypertension (PH) - a normal V/Q scan effectively rules out CTEPH 1
• CT pulmonary angiography should be performed when V/Q scan is indeterminate or shows perfusion defects, though a normal CT angiography cannot exclude operable CTEPH 1
• The final diagnosis requires confirmation of pre-capillary PH (mean PAP ≥25 mmHg, PWP ≤15 mmHg, PVR >2 Wood units) with evidence of multiple chronic/organized occlusive thrombi in pulmonary arteries 1
• Patients with suspected CTEPH should be promptly referred to expert centers with multidisciplinary teams including experienced PEA surgeons 2, 3

Treatment Algorithm

First-Line Treatment: Pulmonary Endarterectomy

• PEA is the gold standard treatment for patients with thromboembolic obstructions in main, lobar, or segmental pulmonary arteries 1, 2
• Patient selection depends on thrombi location, degree of PH, age, and comorbidities - proximal organized thrombi represent ideal indications 1
• A successful PEA can result in dramatic improvement in pulmonary hemodynamics, often with near normalization of pulmonary vascular resistance 1
• PEA should only be performed at centers with sufficient expertise (performing at least 20 operations annually with mortality rate <10%) 1
• Post-PEA, most patients show significant functional improvement, with approximately two-thirds achieving NYHA class I or II status 1

For Inoperable CTEPH or Residual PH After PEA

1. Medical Therapy:

   • Riociguat is the only approved medication specifically for inoperable CTEPH or persistent/recurrent PH after PEA 2, 4
   • Riociguat significantly improves 6-minute walking distance (by 39 meters) and reduces pulmonary vascular resistance compared to placebo 2
   • Other pulmonary arterial hypertension medications (prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors) may be considered off-label in selected patients 1, 5

2. Balloon Pulmonary Angioplasty (BPA):

   • BPA is recommended for inoperable patients with appropriate target lesions 2, 3
   • This procedure has shown promising results with low mortality (<1% in expert centers) 3
   • BPA may also be considered for patients with chronic thromboembolic disease without PH 3

3. Lung Transplantation:

   • Bilateral lung transplantation remains an option for advanced cases unsuitable for PEA or other interventions 1, 3

Adjunctive Therapy

• Lifelong anticoagulation is mandatory for all CTEPH patients, typically with vitamin K antagonists adjusted to a target INR of 2.0-3.0 1, 2
• Inferior vena cava filter placement may be considered to prevent recurrent thromboembolism, though formal studies evaluating efficacy are lacking 1

Multimodal Approach

• Combination of treatments (PEA, BPA, and medical therapy) may be appropriate in carefully selected patients 3, 6
• Patients should be regularly followed at specialized CTEPH centers with at least one hemodynamic assessment 6-12 months after treatment initiation 2

Common Pitfalls and Caveats

• Patients should not be labeled as "inoperable" until reviewed by an experienced PEA surgeon at a specialized center 1
• Medical therapy is not a substitute for PEA in operable patients and should not delay surgical referral 2
• CTEPH can develop in patients without a history of symptomatic pulmonary embolism, so it should be considered in any patient with unexplained PH 5
• Risk factors for CTEPH include splenectomy, ventriculo-atrial shunts, myeloproliferative disorders, and chronic inflammatory bowel diseases 1, 5
• Survivors of acute pulmonary embolism who show signs of PH or right ventricular dysfunction should receive follow-up echocardiography after 3-6 months to detect potential development of CTEPH 1