Impact of functional class change on survival in patients with pulmonary arterial hypertension in the REVEAL registry

Introduction: The Registry to EValuate Early And Long-term PAH Disease Management (REVEAL), a 55-center observational, US-based study, describes current demographic, clinical, and treatment patterns in PAH patients (pts). Objective: Determine if pts who improve from functional class (FC) III at enrollment to FC I/II at follow-up (f/u) have a better 2-year survival than pts who remain FC III. Methods: 1,082 adults enrolled in REVEAL were assessed as FC III at enrollment (based on most recent pre-enrollment evaluation) and had ≥1 f/u FC assessment within the first year after enrollment. We classified pts based on their first FC f/u assessment after enrollment as: 1) improved if FC improved to FC I/II; 2) unchanged if remained FC III; or 3) deteriorated if worsened to FC IV. We compared survival (estimates±SE) of these 3 subgroups from the first f/u FC assessment (log-rank test). Results: FC improved in 26% (n=281) of pts, was unchanged in 66% (n=718) and deteriorated in 8% (n=83). At enrollment, there were no differences in gender, PAH subgroup, right atrial pressure, or cardiac index; significant differences were observed in age, proportion of newly diagnosed (diagnostic confirmatory cardiac catheterization ≤3 months before enrollment) pts, and 6-minute walk distance among groups. Two-year survival was 88±2%, 76±2%, and 34±6% for FC I/II, FC III, and FC IV pts, respectively ( P <0.001 for all pairwise comparisons). Results are similar for both newly and previously diagnosed pts who were FC III at enrollment. Conclusions: Pts who improve from FC III to FC I/II appear to have a better 2-year survival than those who remain FC III.