New guidelines that redefine pulmonary hypertension (PH) by a lower mean pulmonary artery pressure (mPAP) have led to a reported increase in the number of patients given a diagnosis of PH. Although the evaluation and treatment of PH relies on the specialist, as we explain here, family physicians play a pivotal role in the diagnosis, reduction or elimination of risk factors for PH, and timely referral to a pulmonologist or cardiologist who has expertise in managing the disease. We also address the important finding that adult patients who have been evaluated, treated, and followed based on guidelines—updated just last year—have a longer life expectancy than patients who have not been treated properly or not treated at all.
Last, we summarize the etiology, evaluation, and management of PH in the pediatric population.
What is pulmonary hypertension? A revised definition
Prior to 2018, PH was defined as mPAP (measured by right heart catheterization [RHC]) ≥ 25 mm Hg at rest. Now, based on guidelines developed at the 6th World Symposium on Pulmonary Hypertension (WSPH) in 2018, PH is defined as mPAP > 20 mm Hg.1,2 That change was based on studies in which researchers noted higher mortality in adults who had mPAP below the traditional threshold.3,4 There is no evidence, however, of increased mortality in the pediatric population in this lower mPAP range.5
New guidelines that redefine pulmonary hypertension (PH) by a lower mean pulmonary artery pressure have led to a reported increase in the number of patients given a diagnosis of PH.
PH is estimated to be present in approximately 1% of the population.6 PH due to other diseases—eg, cardiac disease, lung disease, or a chronic thromboembolic condition—reflects the prevalence of the causative disease.7
How is pulmonary hypertension classified?
Based on the work of a Task Force of the 6th WSPH, PH is classified by underlying pathophysiology, hemodynamics, and functional status. Clinical classification comprises 5 categories, or “groups,” based on underlying pathophysiology (TABLE 16).
Group 1 PH includes patients with primary pulmonary hypertension, also referred to (including in this article) as pulmonary arterial hypertension (PAH). Hemodynamic criteria that define PAH include pulmonary vascular resistance (PVR) > 2 Woods unitsa and pulmonary capillary wedge pressure > 15 mm Hg. Idiopathic PAH is the most common diagnosis in this group.
The incidence of PAH is approximately 6 cases for every 1 million adults; prevalence is 48 to 55 cases for every 1 million adults. PAH is more common in women.6