Oral and inhaled corticosteroid use and risk of recurrent pulmonary embolism

Chronic inflammatory diseases predispose for development of a first pulmonary embolism (PE). Previous studies showed that corticosteroids, which are the mainstay of treatment for inflammatory diseases, enhance the risk of a first venous thromboembolism. Yet, it is unknown whether corticosteroids also predispose for recurrent events. Therefore, we investigated the association between oral and/or inhaled corticosteroid use and the risk of recurrent PE. We performed a nested case-control study using the PHARMO Database. Adult patients who had suffered from a first PE for which vitamin K antagonists were prescribed, were eligible. Of these, 384 patients with recurrent PE were matched to 1030 patients without recurrent PE. We showed that oral or inhaled corticosteroids was ever used by 22.7% and 20.6% of patients with recurrent PE, and 23.5% and 21.5% of the patients without recurrent PE. There was an overall association between oral corticosteroid use and the risk of recurrent PE (p=0.02). Current use of oral corticosteroids increased the risk of recurrent PE (OR 3.74; 95% CI 2.04-6.87), whereas past use reduced the risk (OR 0.46; 95% CI 0.28-0.74). A similar pattern was observed for inhaled corticosteroids, although less strong (p=0.10). Current use of oral corticosteroids is associated with increased risk of recurrent PE. Whether this increased risk is caused by oral corticosteroids themselves, or by the underlying disease, or both, needs further investigation. Nevertheless, given the frequent use of corticosteroids in clinical practice, clinicians should be aware of this risk