Smoking history and pulmonary arterial hypertension (PAH) onset and clinical outcomes (REVEAL)

Aim: Data on impact of smoking on pulmonary hypertension is conflicting. REVEAL (Registry to Evaluate Early and Long-term PAH Disease Management) a US-based, multicentre observational registry characterising clinical features and outcomes of PAH patients (pts) was queried to assess the relationship between smoking status (NEVER- vs EVER-smoker) and onset and outcome in PAH. Methods: REVEAL (NCT00370214) pts ≥18 years (yrs), group 1 PAH, with pulmonary capillary wedge pressure ≤15 mmHg at diagnosis were included. 5-yr mortality (all cause), the composite of transplant or mortality and time to first hospitalisation were evaluated for NEVER- vs EVER-smokers, and by newly vs previously diagnosed pts unadjusted (un-) and adjusted (adj) for age, time from diagnosis to enrolment, sex and log transformed pulmonary vascular resistance (PVR). Results: NEVER (N=1619) vs EVER-smokers (N=1427) differed for: median age at diagnosis, 48.3 vs 52.5 years; obstructive lung disease, 7.8% vs 21.7%; male, 15.2% vs 27.8% (all p<0.001). 5-yr mortality did not differ for EVER- vs NEVER-smokers overall. Newly diagnosed EVER-smokers vs NEVER smokers (adj and un- for PVR and gender) had a higher risk of mortality (adj hazard ratio [HR] 1.33 [95% CI, 1.05-1.69; p=0.019]; un- HR 1.41, 95% CI 1.12-1.78, p=0.0039); composite of transplant or mortality (adj HR 1.38 [95% CI, 1.09–1.73 p=0.007]; un- HR 1.46 [95% CI 1.16-1.83,p=0.0012]) and hospitalisation (adj HR 1.25 [95% CI, 1.03–1.51; p=0.022]; un- HR 1.27 [95%CI 1.06-1.53, p=0.0012]). Conclusions: In REVEAL, PAH pts who were EVER- vs NEVER-smoker were older at diagnosis. In newly diagnosed PAH pts smoking was associated with worse clinical outcomes irrespective of PVR.