Treprostinil is a vasodilator approved for the treatment of Pulmonary Hypertension (PH). It dilates downstream blood vessels, reducing mean pulmonary arterial pressure (mPAP), peripheral vascular resistance (PVR), and right ventricular (RV) workload. This study combines clinical data and in-silico modelling to explore preliminary insights into commonalities among treatment responders. Pilot data from 4 PH patients who responded to therapy were analyzed, focusing on structural remodelling and pulmonary artery (PA) flow patterns. Previous literature suggested that the duration of a pathological vortex in the main PA trunk, t_{vortex}, correlates with mPAP, and the current study aims to test the hypotheses that t_{vortex} is altered due to the dual action of change in PVR along with the corresponding remodelling, and that the closer the point is to the correlation line, the more adapted the system is. Findings indicate that, in the studied cases, while RV function and proximal PA geometry remained relatively unchanged after treatment, there was remodelling in distal vessels. mPAP and t_{vortex} decreased after 6 months on medication. Consequently, the responders' haemodynamic state, as defined by mPAP and t_{vortex}, became aligned with the literature correlation line. The change in distance from the correlation line at follow-up was found to be inversely proportional to the starting distance, suggesting a potential diagnostic marker (R^2 = 96%) to identify responders.