What are the criteria for initiating pulmonary vasodilators in adults with pulmonary hypertension (PH) secondary to respiratory insufficiency?

From the Guidelines

Pulmonary vasodilators should not be initiated in adults with pulmonary hypertension secondary to respiratory insufficiency as first-line therapy, but rather after optimization of the underlying respiratory condition and evidence of severe pulmonary hypertension with right ventricular dysfunction, as recommended by the 2019 Chest guideline update 1. The decision to start pulmonary vasodilators in adults with pulmonary hypertension secondary to respiratory insufficiency should be based on a comprehensive evaluation of the patient's condition, including right heart catheterization, echocardiography, pulmonary function tests, and arterial blood gases to confirm the diagnosis and exclude other causes of pulmonary hypertension.

• The primary goal of therapy in PH-LHD is to improve global management of the underlying condition prior to considering specific measures to treat PH, as stated in the 2015 ESC/ERS guidelines 1.
• Some patients may benefit from non-specific vasodilators such as nitrates and hydralazine, although evidence supporting this strategy is limited 1.
• The use of PAH therapies in PH-LHD is not supported by strong evidence, and most studies carry significant methodological limitations 1.
• A recent multicentre, placebo-controlled trial found no effect of riociguat on the primary endpoint of change in PAPm after 16 weeks in patients with PH due to systolic heart failure 1.
• The 2019 Chest guideline update recommends the use of phosphodiesterase-5 inhibitors, endothelin receptor antagonists, and prostacyclin analogs in the treatment of pulmonary arterial hypertension, but emphasizes the importance of individualized treatment and careful monitoring of patients 1.
• Regular monitoring of liver function, hemoglobin, and renal function is necessary during treatment with pulmonary vasodilators, as they may have adverse effects on these parameters.
• The medications work by promoting vasodilation and reducing vascular remodeling in the pulmonary circulation, thereby decreasing right ventricular afterload and improving cardiac output, but should be used cautiously as they may worsen ventilation-perfusion mismatch and hypoxemia in some patients with respiratory disease.

From the Research

Criteria for Starting Pulmonary Vasodilators

The decision to start pulmonary vasodilators in adults with pulmonary hypertension secondary to respiratory insufficiency depends on various factors, including the underlying cause of the pulmonary hypertension, the severity of the disease, and the patient's overall health status.

• The diagnosis of pulmonary hypertension is typically made using a combination of clinical evaluation, echocardiography, and right heart catheterization 2, 3, 4.
• Patients with pulmonary hypertension secondary to respiratory insufficiency may be considered for pulmonary vasodilator therapy if they have a mean pulmonary artery pressure greater than 20 mmHg and symptoms of dyspnea on exertion 3, 5.
• The choice of pulmonary vasodilator depends on the specific underlying cause of the pulmonary hypertension, as well as the patient's response to treatment 2, 5.
• Patients with pulmonary hypertension due to chronic lung disease may require a different treatment approach than those with pulmonary hypertension due to left-sided heart disease or other causes 2, 5.

Diagnostic Evaluation

The diagnostic evaluation for pulmonary hypertension typically includes:

• Electrocardiography
• Chest radiography
• Pulmonary function tests
• Transthoracic echocardiography to estimate the probability of pulmonary hypertension 2
• Right heart catheterization to confirm the diagnosis and classify the disease 2, 3, 6, 4

Treatment Approach

The treatment approach for pulmonary hypertension secondary to respiratory insufficiency depends on the underlying cause of the disease and the patient's overall health status.

• Patients with pulmonary hypertension due to chronic lung disease may require oxygen therapy, bronchodilators, and other treatments to manage their underlying lung disease 5.
• Patients with pulmonary hypertension due to left-sided heart disease may require treatment to manage their underlying heart disease, such as diuretics, beta blockers, and other medications 2, 5.
• Pulmonary vasodilators, such as phosphodiesterase type 5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogues, and prostacyclin receptor agonists, may be considered for patients with pulmonary hypertension who do not respond to other treatments 2, 5.