Pulmonary arterial hypertension: exposure to air pollution tied to disease severity, poor outcomes

  • Sofianopoulou E & al.
  • Eur Respir J
  • 28 Mar 2019

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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Takeaway

  • In idiopathic/heritable pulmonary arterial hypertension (PAH), indirect measures of exposure to traffic-related air pollution are associated with disease severity at baseline.
  • Higher exposure to particulate matter ≤2.5 μm3 (PM2.5) is associated with poorer transplant-free survival.

Why this matters

  • Exposure to traffic and air pollution is associated with increased mortality in numerous diseases, but its association with disease severity and outcomes in PAH remains unknown.

Study design

  • 301 patients with PAH from the UK PAH national cohort study were evaluated for exposure to PM2.5, nitrogen dioxide (NO2) and indirect measures of traffic-related air pollution.
  • Primary outcome: transplant-free survival.
  • Association of air pollution markers with disease severity and European Society of Cardiology/European Respiratory Society risk (ERS/ESC) stratification were assessed.
  • Funding: None disclosed.

Key results

  • After adjustment for confounders, higher exposure to PM2.5 was associated with increased risk for death or lung transplant (HR, 4.38 per 3 μg/m3; P=.009).
  • No significant associations were seen between recent exposure to PM2.5 at baseline catheterisation, NO2 or traffic-related pollution indicators and mortality.
  • Indirect measures of exposure to traffic-related air pollution within the 500-1000 m buffer zones associated with the ERS/ESC risk categories and pulmonary haemodynamic severity at baseline.
  • This association was strongest for pulmonary vascular resistance and 200 m increase in distance to road (relative change, 0.95; P=.001).
  • Higher exposure to PM2.5 was associated with lower pulmonary vascular resistance, and no consistent association was found between pulmonary haemodynamics and NO2 exposure.

Limitations

  • Air pollution exposure estimated using the 2010 annual air pollution maps.