Pulmonary arterial hypertension (group 1 pulmonary hypertension)





This chapter will review the pharmacotherapy for treatment of pulmonary arterial hypertension (PAH) according to the 2019 CHEST Guideline.


Definitions




  • •

    Pulmonary hypertension (PH) is characterized by mean pulmonary arterial pressure (mPAP) ≥20 mm Hg at rest and pulmonary vascular resistance three or more wood units measured by right heart catheterization. The World Health Organization (WHO) classifies PH into five groups based on etiologies ( Table 17.1 ).



    Table 17.1

    World Health Organization of Clinical Classification of PH

    Adapted from Simonneau G, Robbins IM, Beghetti M, et al. Updated clinical classification of pulmonary hypertension. J Am Coll Cardiol . 2009;54:S43–S54.


















    Group 1 PAH
    Group 2 PH caused by left heart disease
    Group 3 PH caused by lung disease and/or hypoxia
    Group 4 Chronic thromboembolic PH
    Group 5 Unclear multifactorial mechanisms

    PAH , Pulmonary arterial hypertension; PH , Pulmonary hypertension


  • •

    PAH is Group 1 PH caused by idiopathic and heritable causes, drugs, connective tissue disease, congenital heart disease, human immunodeficiency virus, portopulmonary hypertension, schistosomiasis, pulmonary venoocclusive disease, or PH of the newborn.



Functional class


See Table 17.2



Table 17.2

World Health Organization of Functional Class (WHO-FC)

Adapted from Rubin LJ, American College of Chest Physicians. Diagnosis and management of pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines. Chest . 2004;126(1 suppl):7S–10S.


















CLASS DEFINITION
I No symptoms (dyspnea, fatigue, syncope, chest pain) with normal activities
II Symptoms with strenuous normal daily activities; slight limitations in functional status/activity level
III Symptoms with normal daily activities; severe limitation in functional status/activity level
IV Symptoms at rest; unable to perform normal daily activities without symptoms


Management of PAH


Supportive therapy




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    Oxygen: maintain SaO 2 ≥90% and PaO 2 ≥60 mm Hg.


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    Diuretics: for the symptomatic management of right ventricular (RV) dysfunction and fluid overload.


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    Digoxin: consider in atrial tachyarrhythmias.


  • •

    Anticoagulation: may consider in idiopathic PAH, heritable PAH, and PAH secondary to anorexigenic agent use (conflicting data).



Treatment algorithm


See Fig. 17.1




Figure 17.1


Treatment Algorithm for Pulmonary Arterial Hypertension (PAH) in Adults.

From Klinger JR, Elliott CG, Levine DJ, et al. Therapy for pulmonary arterial hypertension in adults. Update of the CHEST guideline and expert panel report. Chest. 2019;155(3):565–586 . Where multiple drug options are provided, there are no comparative effectiveness data to suggest greater benefit of one therapy over the other. 6MWD , 6-min walk distance; CCB , Calcium channel blocker; FC , Functional class; PAH , Pulmonary arterial hypertension; PH , Pulmonary hypertension; RV , Right ventricular; WHO , World Health Organization. Refer to Reference 3 for recommendation numbers. * Combination therapy carries with it costs and potential for increased adverse effects and drug interactions. ** No data available for the oral/inhaled prostanoids use in whom parenteral prostanoids are indicated. *** Lung transplantation is outside the scope of this guideline and has not been evaluated by this panel.














Vasodilator therapy with calcium channel blockers if demonstrates acute vasoreactivity.




  • •

    Diltiazem extended-release (ER) 240–720 mg daily.


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    Amlodipine up to 20 mg daily.


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    Nifedipine ER 120–240 mg daily.


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    Avoid in RV dysfunction, depressed cardiac output, or WHO Functional Class IV symptoms.



Targeted therapies


Agents targeting the prostacyclin pathway ( table 17.3 )



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Feb 28, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Pulmonary arterial hypertension (group 1 pulmonary hypertension)

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