Abstract
Introduction: Many patients with severe asthma need inhaled (ICS) and chronic oral (OCS) corticosteroids for asthma control. OCS are associated with hypercoagulability and increased risk of venous thromboembolism (VTE). Also asthma itself is associated with a prothrombotic state (Brims 2009).
Hypothesis: The incidence of VTE is increased in asthma, and associated with asthma severity and OCS use.
Methods: 166 Outpatients with mild-moderate asthma (mean (range) age 49yr (18-80), 56% female, all using ICS), and 139 patients with severe asthma (52yr (18-77), 62% female, 39% using OCS) from 3 clinics in the Netherlands and Davos, Switzerland, were consecutively included in a cross-sectional study. Patients completed a questionnaire about previous VTE, risk factors and medication use. All VTE events were objectively diagnosed. Data were compared with the available incidence (ages 50-54 yr) in the general population (Naess 2007).
Results: Deep vein thrombosis (DVT) occurred in 3 and 2 patients with severe and mild-moderate asthma resp. and pulmonary embolism (PE) in 11 and 3. Overall incidence was 1.77/1000 person yr in severe asthma vs 0.7 in mild-moderate asthma and 1.03 in the general population. The relative risk of PE for severe asthma was 5.5 (95% CI: 1.24-24) and independently associated with >2 exacerbations/yr (RR 12.63, 1.48-107) and chronic OCS use (RR 8.21, 1.57-43). The risk of DVT was 0.50 (0.13-1.96). In mild-moderate asthma risks were not increased.
Conclusions: Patients with severe asthma have a 5.5-fold increased incidence of pulmonary embolism, which is associated with exacerbation frequency and chronic oral corticosteroid use.
Implication: Pulmonary embolism may be important in the prognosis and management of severe asthma.
- © 2011 ERS