Pulmonary Hypertension

Pulmonary Hypertension – Kaele Leonard

Background

  • Symptoms: dyspnea, exertional chest pain, fatigue, edema (legs, abdomen), exertional lightheadedness or syncope, palpitation
  • Exam: JVD, increased P2, split S2, RV heave, TR murmur, hepatomegaly, ascites, edema
  • Signs of RV failure: low cardiac output (hypotension, renal failure, hepatic congestion), arrhythmias, refractory hypoxemia (R→L shunt), effusions (pericardial > pleural)
  • WHO Groups and Causes:
  1. Pulmonary arterial hypertension (PAH): obliteration of blood vessels in the lung
    • Idiopathic, heritable
    • Drugs/toxins (methamphetamine)
    • Associated with CTD, HIV, portal HTN, congenital heart disease, schistosomiasis
    • Pulmonary veno-occlusive disease (PVOD), pulmonary capillary hemangiomatosis
  2. Left heart disease: back pressure and passive congestion
    • HFrEF, HFpEF, valvular disease, LA stiffness
  3. Chronic lung disease: chronic hypoxemia àchronic pulmonary vasoconstriction
    • COPD, ILD, OSA, chronic high-altitude, developmental lung disorders
  4. Pulmonary artery obstruction and thrombi: obstruction due to chronic clot material
    • Chronic thromboembolic pulmonary hypertension (CTEPH)
  5. Unclear or multifactorial mechanisms
    • Hematologic disorders, chronic hemolytic anemia, sarcoidosis, pulmonary Langerhans cell histiocytosis, fibrosing mediastinitis, metabolic disorders

 

Evaluation

  • Consult pulmonary hypertension with any questions or assistance with workup. Below are studies to consider ordering to determine etiology/group of pulmonary hypertension
  • Labs: BNP, rheumatologic studies (ANA, RF), HIV
  • CXR: increased right heart border, increased PA
  • EKG: RVH, RAD
  • TTE w/ bubble: RVSP >35-40, RV dilation and dysfunction, RA dilation, septal flattening, pericardial effusion, evaluate for L heart disease and shunt
  • PFTs: decreased DLCO in PH, evaluate for parenchymal lung disease
  • VQ scan or CTA chest: evaluate for CTEPH
    • Pulmonary angiogram (evaluate for surgical candidacy for pulmonary endarterectomy)
  • + CT chest: evaluate for parenchymal lung disease
  • + ABG: evaluate for hypoxemia or hypercarbia
  • + Sleep study: evaluate for OSA

 

Right heart catheterization (RHC): diagnose PH and determine pre- vs post-capillary

  • See RHC section for hemodynamic assessment
  • Nitric oxide challenge assess for drug response
  • Fluid challenge assess left heart compliance

 

Definitions

Characteristics

Causes

Pre-capillary PH

mPAP > 20 mmHg

PAWP ≤ 15 mmHg

PVR ≥ 3 WU

Groups 1, 3, 4, 5

Post-capillary PH

mPAP > 20 mmHg

PAWP > 15 mmHg

PVR < 3 WU

Group 2

Combined pre- and post-

capillary PH

mPAP > 20 mmHg

PAWP > 15 mmHg

PVR ≥ 3 WU

Group 2, 5

 

Management

  • General: treat underlying cause; Diuretics for right heart failure; Oxygen goal SpO2 > 90%
  • PAH medicines: Consult pulmonary hypertension for consideration to start or change thes
    • Oral treatments may be used as monotherapy or in combination
      • Calcium-channel blockers patients with + vasoreactive challenge
      • NO-cGMP enhancers: PDE5-inhibitors sildenafil or tadalafil, riociguat
      • Endothelin receptor antagonists (ERAs): bosentan, macitentan, ambrisenta
      • Prostacyclins:
      • Epoprostenol: IV (Veletri) or inhaled (Flolan), half-life 4 minutes
      • Treprostinil: IV/subcutaneous/inhaled/PO, half-life 4 hours
      • Iloprost: inhaled, half-life minutes
      • Selexipag (Uptravi): PO, half-life hours
      • Side effects: headache, jaw pain, flushing, diarrhea, arthralgias
  • Treatment based on NYHA functional classification:
    • Class I: no treatment or monotherapy
    • Class II: monotherapy or combination oral therapy
    • Class III: combination oral therapy or prostacyclin
    • Class IV: prostacyclin +/- oral therapy
  • Lung transplant for patients who are candidates and failing maximal medical therapy
  • V-A ECMO can be used as bridge to medical therapy or lung transplant
  • Palliative measures
    • Atrial septostomy – serves as “pop-off” valve and allows for decompression of failing RV; used as definitive palliative procedure or bridge to lung transplant