Lack of association between airflow limitation and recurrence of venous thromboembolism among cancer patients with pulmonary embolism

Background: COPD is a well-known risk factor for venous thromboembolism (VTE) development. However, recent data showed that it was not associated with VTE recurrence risk, which excluded cancer patients. This study investigated the association of airflow limitation and VTE recurrence in cancer patients with pulmonary embolism (PE). Methods: This is a retrospective cohort study of cancer patients with newly diagnosed PE at a university hospital. PE was confirmed using contrast-enhanced computed tomography scan. Airflow limitation was defined as pre-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC)<0.7 within 2 years of PE diagnosis. VTE recurrence was defined as a composite of recurrence as PE or deep vein thrombosis or both. Results: Among 401 cancer patients with newly diagnosed PE, spirometry-based airflow limitation was observed in 126 (31.4%) patients. Half of the patients had lung cancer, which was more common in the group with airflow limitation (65.1% vs 42.9%, p<0.001). Symptomatic PE was present in less than half (45.4%) of the cases, and 62.6% of patients were treated for PE. During the median follow-up period of 9.7 months, VTE recurred in 49 (12.2%) patients. Compared with patients without airflow limitation, those with airflow limitation did not have an increased risk of VTE recurrence in univariate or multivariate analyses (adjusted hazard ratio, 1.29 [95% CI 0.68, 2.45]). Conclusion: The presence of airflow limitation did not increase the risk of VTE recurrence in cancer patients with PE. Prospective studies are needed to validate this finding.