Pulmonary Hypertension¶
Pakinam Mekki
Background¶
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Symptoms: insidious dyspnea, exertional chest pain, orthopnea, PND, edema
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Exam: JVD, increased P2, split S2, RV heave, TR murmur, hepatomegaly, ascites, edema
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Signs of RV failure: low cardiac output (hypotension, renal failure, hepatic congestion), arrhythmias, refractory hypoxemia (R→L shunt), effusions (pericardial > pleural)
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WHO Groups and Causes:
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Group 1: Pulmonary arterial hypertension (PAH): obliteration of blood vessels in the lung
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Idiopathic, heritable
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Drugs/toxins (methamphetamine)
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Associated with CTD, HIV, portal HTN, congenital heart disease, schistosomiasis
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Pulmonary veno-occlusive disease (PVOD), pulmonary capillary hemangiomatosis
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Group 2: Left heart disease: back pressure and passive congestion
- HFrEF, HFpEF, valvular disease, LA stiffness
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Group 3: Chronic lung disease: chronic hypoxemia, chronic pulmonary vasoconstriction
- COPD, ILD, OSA, chronic high-altitude, developmental lung disorders
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Group 4: Chronic thromboembolic pulmonary hypertension (CTEPH)
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Group 5: Multifactorial
- Hematologic disorders, chronic hemolytic anemia, sarcoidosis, pulmonary Langerhans cell histiocytosis, fibrosing mediastinitis, metabolic disorders
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Evaluation¶
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Most common reason for admission with a known diagnosis of pHTN is volume overload/RV failure and hypoxia
- Consider etiology of decompensation: Progression of underlying disease, medication/dietary nonadherence, infection, arrhythmia, myocardial infarction/RV ischemia, shunting via opening a PFO as a release valve, pulmonary embolism
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Consult pulmonary hypertension with any questions or assistance with workup
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Studies to consider ordering to determine etiology of pulmonary hypertension
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Labs: BNP, liver enzymes, rheumatologic serologies (ANA w/ reflex ENA, RF/CCP, ANCA, Scl-70, Ro/LA)
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EKG: R-axis deviation, RBBB, increased P wave in lead II
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CXR: increased PA and R heart border, vascular pruning
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TTE w bubble: RVSP >35-40, RV dilation and dysfunction, RA dilation, septal flattening, pericardial effusion, evaluate for L heart disease and shunt
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PFT (outpatient): isolated decrease in DLCO in group I PH, TLC \< 50%, FEV/FVC \< 70%
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V/Q scan or CTA chest to evaluate for CTEPH
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6-minute walk test is prognostic, can be used to monitor response to therapy
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± CT chest to evaluate for parenchymal lung disease
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± sleep study to evaluate for OSA
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Right heart catheterization (RHC) is the gold standard test for PH diagnosis and determines pre-vs post-capillary HTN (See RHC section in Cardiology)
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Nitric oxide challenge to assess for drug response
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Fluid challenge with 500cc LR to assess left heart compliance `
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Definitions | Characteristics | Causes |
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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 |
Poor Prognostic Indicators for pHTN¶
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NYHA Functional Class (FC III-IV) - 6-minute walk test \< 300
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AKI - Hyponatremia
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Low SBP (SBP \< 90) - CTD or liver disease as etiology
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Poor hemodynamics on RHC (RAP > 20; cardiac index \< 2)
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TTE findings - TAPSE \< 1.8, pericardial effusion, severe RV dysfunction
Management¶
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Goal of hospitalization is to understand and optimize hemodynamics
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Overall goal- improve NYHA functional class, RV function, 6-minute walk test, quality of life
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General management: treat underlying cause, diuretics for right heart failure, goal SpO2>90%
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PAH medicines: Consult pulmonary hypertension if considering starting of changing meds
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Oral treatments may be used as monotherapy or in combination
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Calcium-channel blockers → patients with + vasoreactive challenge
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NO-cGMP enhancers: PDE5-inhibitors sildenafil or tadalafil, riociguat
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Endothelin receptor antagonists (ERAs): Bosentan, macitenatan, ambrisentan –
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Prostacyclin analogs
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Prostacyclin analogs increase cAMP-mediated pulmonary vasodilation. Side effects include jaw pain, flushing, arthralgia, diarrhea.
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IV formulations are administered through a continuous pump. Never stop IV prostacyclins, even brief pauses can cause rebound vasoconstriction and death. In an emergency, can run temporarily through PIV
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Epoprostenol: IV (Veletri) or inhaled (Flolan), half-life 4 minutes.
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Treprostinil: IV/subcutaneous/inhaled/PO, half-life 4 hours
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Iloprost: inhaled, half-life minutes
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Selexipag (Uptravi): PO, half-life hours
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Treatment based on NYHA functional classification:
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Class I: no treatment or monotherapy
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Class II: monotherapy or combination oral therapy
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Class III: combination oral therapy or prostacyclin
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Class IV: prostacyclin ± oral therapy
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Lung transplant for patients who are candidates and failing maximal medical therapy
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VA ECMO can be used as bridge to medical therapy or lung transplant
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Atrial septostomy- serves as “pop-off” valve and allows for decompression of failing RV; used as definitive palliative procedure or bridge to transplant