Survival in incident and prevalent cohorts of patients with pulmonary arterial hypertension

TLDR

Pulmonary arterial hypertension is a progressive, fatal disease. The study prospectively enrolled 674 adult PAH patients in the French registry and performed two survival analyses: a 3‑year follow‑up of the entire cohort and a focused analysis of incident idiopathic/familial/anorexigen‑associated cases combined with recently diagnosed prevalent patients. In the 674‑patient cohort, 1‑, 2‑, and 3‑year survival were 87%, 76%, and 67%, respectively, and survival was higher in prevalent idiopathic/familial/anorexigen‑associated PAH than in incident cases; a multivariable risk‑prediction equation based on sex, 6‑min walk distance, and cardiac output at diagnosis accurately estimated survival, underscoring survivor bias in prevalent cohorts.

Abstract

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease. We studied 674 consecutive adult patients who were prospectively enrolled in the French PAH registry (121 incident and 553 prevalent cases). Two survival analyses were performed. First, the cohort of 674 patients was followed for 3 yrs after study entry and survival rates described. Then, we focused on the subset with incident idiopathic, familial and anorexigen-associated PAH (n = 56) combined with prevalent patients who were diagnosed <3 yrs prior to study entry (n = 134). In the cohort of 674 patients, 1-, 2-, and 3-yr survival rates were 87% (95% CI 84–90), 76% (95% CI 73–80), and 67% (95% CI 63–71), respectively. In prevalent idiopathic, familial and anorexigen-associated PAH, 1-, 2-, and 3-yr survival rates were higher than in incident patients (p = 0.037). In the combined cohort of patients with idiopathic, familial and anorexigen-associated PAH, multivariable analysis showed that survival could be estimated by means of a novel risk-prediction equation using patient sex, 6-min walk distance, and cardiac output at diagnosis. This study highlights survivor bias in prevalent cohorts of PAH patients. Survival of idiopathic, familial and anorexigen-associated PAH can be characterised by means of a novel risk-prediction equation using patients' characteristics at diagnosis.