Objective: New York Heart Association/World Health Organization functional class (FC) is associated with outcomes in pulmonary arterial hypertension (PAH). We assessed whether patients with PAH who improve from FC III to FC I/II have improved survival vs patients who remain at FC III or worsen to FC IV.
Methods: Patients aged ≥ 19 years with FC III PAH from the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL Registry) (N = 982) were categorized as improved, unchanged, or worsened according to their change in FC from enrollment to first follow-up assessment within 1 year of enrollment. Kaplan-Meier estimates of 3-year survival from first follow-up and changes in 6-min walk distance (6MWD) from enrollment to first follow-up were determined. Subgroup analyses were conducted by cause (ie, idiopathic/familial, connective tissue disease [CTD], congenital heart disease) and time of diagnosis (ie, newly or previously diagnosed [diagnostic right-sided heart catheterization within or ≥3 months of enrollment, respectively]).
Results: Overall, 27% of patients improved FC. Survival was better in patients whose FC improved (84%±2%, n=263) vs those who remained unchanged (66%±2%, n=645) or worsened (29%±6%, n=74) (all P<.001). Survival was also better in patient subgroups whose FC improved vs those who remained unchanged (idiopathic/familial [P<.001], CTD-associated PAH [P=.009], whether newly [P=.004] or previously diagnosed [P<.001]). 6MWD improvements were greater in patients whose FC improved vs those who remained unchanged in the overall (P<.001) and CTD (P=.028) cohorts.
Conclusion: Patients with PAH who improve from FC III to I/II, whether newly or previously diagnosed and regardless of PAH cause, have better survival vs patients who remain FC III.
Trial registry: ClinicalTrials.gov; No.: NCT00370214; URL: www.clinicaltrials.gov.