Hemodynamic heterogeneity of connective tissue disease patients with borderline mean pulmonary artery pressure and its distinctive characters from those with normal pulmonary artery pressure: a retrospective study.

To clarify whether patients with connective tissue disease (CTD)-associated borderline mean pulmonary artery pressure (mPAP) have distinctive hemodynamic characteristics from those with normal mPAP and whether pathogenesis is as heterogeneous as manifest pulmonary hypertension (PH). Seventy-five CTD patients who underwent right heart catheterization (RHC) from 2008 through 2016 were retrospectively analyzed. We compared between-group differences in clinical and hemodynamic findings: normal mPAP (n = 35), borderline mPAP (n = 15), and PH (n = 25). A therapeutic intervention trial based on RHC results was performed in nine patients. The values of tricuspid regurgitation pressure gradient (TRPG) in patients with borderline mPAP were comparable at rest but became higher after exercise compared to those with a normal mPAP (P = 0.01). Pulmonary artery wedge pressure in patients with borderline mPAP was higher than in those with normal mPAP (P < 0.0001) and comparable to those with PH. Each of the three patients was treated for pre-capillary and post-capillary disease and two for interstitial lung disease (ILD). During the mean follow-up period of 40 months, mPAP or TRPG normalized in all patients treated for pre-capillary and post-capillary disease. One patient with severe ILD developed to PH and died from it. CTD patients with borderline mPAP, the underlining pathogenesis of which is heterogeneous as PH, have distinctive hemodynamic characteristics from those with normal mPAP. Whether a specific treatment targeting the inflammatory process or local hemodynamics may alter the clinical course to PH is a topic for future research.