Changes in hemodynamic classification over time are common in systemic sclerosis-associated pulmonary hypertension:...

Group classification of pulmonary hypertension (PH) is based on pulmonary artery wedge pressure (PAWP) on right heart catheterization (RHC). How hemodynamics, particularly PAWP, change over time in systemic sclerosis (SSc)-PH patients is unknown. SSc-PH patients enrolled in the prospective observational PHAROS registry who had > 1 RHC (n = 120) were included in this analysis. Patients were considered to have a "PAWP class change" if they had a PAWP ≤ 15 mmHg on RHC-1 and then a PAWP > 15 on RHC-2 or had a PAWP > 15 on RHC-1 and then PAWP ≤ 15 on RHC-2. There was a median time of 1.4 years between RHC-1 and RHC-2 and 75% of patients had a PH medication added after their initial RHC. PAWP increased significantly (11 ± 5 versus 13 ± 6 mmHg, P = 0.01) between RHC-1 and RHC-2, particularly for patients who were started on PH medications. Overall, 30% of patients who had a repeat RHC experienced a PAWP class change between their initial and follow-up RHC, independent of whether a PH medication was added. Patients initially classified as World Health Organization group 2 PH were most likely to change PAWP class over time. In conclusion, PAWP values commonly change to a significant degree in SSc-PH, which highlights the challenges in using a single time-point PAWP to define clinical classification groups.