Patient rated WHO functional class and psychological distress are strongly associated with dyspnoea in pulmonary hypertension

Background: Little is understood about the characteristics of dyspnoea in patients with pulmonary hypertension (PH), and its severity is likely influenced by multiple factors. The aim of this study was to determine the relationship of dyspnoea with demographic and clinical variables. Methods: Dyspnoea-12 (D-12) (0-36, higher scores denote worse dyspnoea), FC (completed independently by clinicians FC-c and patients FC-p), Hospital Anxiety and Depression Scale, and the Functional Fatigue Scale were completed at baseline, 6 and 12 months. The data for all time points were analysed using multilevel linear regression of measurements to determine independent correlates of dyspnoea. Results: 185 patients with PH (mean age 56 years, SD 13; female 68%, FC-c I 2%, II 38%, III 53%, IV 7%) were enrolled; 139 remained at 6 months and 123 at 12 months. The mean level of D-12 scores for all time points combined was 10.8 SD 9.1, representing a moderate degree of dyspnoea; there was no significant difference in scores over time (p=0.35). FC-c was associated with D-12 scores at baseline (p <0.001), but was not significant at follow-up points and removed from the model. A backwards selection procedure was performed to retain only the significant variables in the final regression model and included WHO-p, anxiety and fatigue (all