2.1. Study Design

This is a retrospective descriptive study of data obtained from the pulmonary hypertension registry (PHR) at the University of Manitoba (Health Science Centre, Winnipeg, MB). The data in the PHR is collected prospectively from a patient's initial assessment throughout every clinic visit following treatment initiation (approximately every 3 months). The PHR includes comprehensive data related to demographics, comorbidities, prior and concomitant medications, all required investigations to establish a proper diagnosis including invasive and noninvasive hemodynamic parameters, WHO functional class, and 6-minute walk distance (6-MWD). Data collection into the PHR was approved by the University of Manitoba research ethics board.