An evaluation for SAPH should be considered whenever dyspnea appears to be disproportionate to the severity of the coexisting pulmonary sarcoidosis, when severe pulmonary sarcoidosis is present, or when right heart failure is present [18]. Echocardiography remains the mainstay of initial non-invasive evaluation for SAPH (see Fig. 13.3). An elevated right ventricular systolic pressure (RVSP) and/or features indicative of right heart remodeling including right ventricular enlargement, hypertrophy, and systolic dysfunction should raise the suspicion SAPH. However, reliance upon the use RVSP as an estimation of pulmonary artery systolic pressure can be misleading, particularly in patients with parenchymal lung disease [19, 20].

A multimodality testing approach should be incorporated into the initial SAPH evaluation (see Fig. 13.4). Electrocardiography may indicate the presence of right heart remodeling and corroborate echocardiographic findings. Chest radiographic staging of pulmonary sarcoidosis has utilized the Scadding score and stages patients from I to IV based upon the presence or absence of bilateral hilar lymphadenopathy, pulmonary infiltrates, fibrosis, and bullae [21]. The presence of an advanced Scadding stage should prompt consideration of the SAPH. The finding of ground glass attenuation, septal lines, and extrinsic compression of the pulmonary arteries by mediastinal adenopathy during chest computed tomography has been shown to be associated with SAPH [5]. Main pulmonary enlargement (PA) >29 mm or a ratio of the PA to aortic dimensions >1 has been proposed as a screening tool for PH, but its performance in SAPH has yet to be tested [22]. Surprisingly, neither spirometry, lung volumes, diffusion capacity, exertional hypoxemia, or 6 minute walk distance have proven to be reliably predictive of SAPH [3, 23, 24]. The relatively poor utility of these screening tests likely reflects not only the heterogeneous forms of SAPH but also the inherent limitations of each modality. Therefore, an optimal screening strategy should not rely upon individual test results but rather the composite of multiple tests as well as a symptoms, clinical course, and phenotype before determining whether to pursue diagnostic testing.

As with all forms of PH, the diagnosis of SAPH cannot be made noninvasively and requires a right heart catheterization to demonstrate an elevated mean pulmonary arterial pressure (mPAP) ≥25 mmHg [25]. This contrasts the diagnosis of PAH, which also requires elevated mPAP without an elevated left ventricular filling pressure as indicated by pulmonary capillary wedge pressure or left ventricular end diastolic pressure of ≤15 mmHg (see Fig. 13.5).

In contrast to the well-established treatment algorithms for PAH, the optimal treatment approach to SAPH remains an area of controversy and active investigation. However, it is generally agreed upon that modifiable comorbid conditions that potentially contribute to SAPH should be identified and treated, including hypoxemia, obstructive sleep apnea, left ventricular systolic and/or diastolic dysfunction, hypervolemia, and thromboembolic disease. Although corticosteroid therapy is theoretically appealing, its effect on pulmonary hemodynamics in small series has been highly variable and discrepant from improvement in pulmonary mechanics [26–28].

SAPH patients are more likely to experience debilitating dyspnea, exercise intolerance, and reduced functional capacity [34, 35]. In a population with pulmonary sarcoidosis awaiting lung transplant, the presence of PH predicted a poor prognosis [36, 37]. The estimated 5-year survival for SAPH is only 59 %. Little is known about the impact of pulmonary vasodilator therapy on mortality in SAPH.