Purpose: The routine use of modern computed tomography scanners has led to an increased detection of incidental pulmonary embolism (PE), in particular in patients with cancer. The clinical relevance of these incidental findings is unknown.
Patients and methods: In this retrospective cohort study, oncology patients in whom PE was objectively proven between 2004 and 2010 and anticoagulant treatment was started, were included. Fifty-one patients with incidental PE and 144 with symptomatic PE were observed for 1 year to compare the risks of recurrent venous thromboembolism (VTE), bleeding complications, and mortality. Kaplan-Meier and Cox survival analyses were performed.
Results: Incidental and symptomatic patients did not differ with respect to mean age, sex, cancer type and stage, and risk factors for VTE. As a result from evolving treatment guidelines, approximately half of the patients in both groups received long-term treatment with vitamin K antagonists in stead of currently recommended low-molecular-weight heparin. The 12-month cumulative incidence of recurrent VTE was 13.3% in the incidental group versus 16.9% in the symptomatic group (P = .77). Notably, 20% VTE events recurred after premature termination of anticoagulant therapy. The risk of major bleeding complications was also comparable in the two groups (12.5% for incidental patients and 8.6% for symptomatic patients; P = .5). The respective 12-month mortality risks were 52.9% and 53.3% (P = .7).
Conclusion: Our findings suggest that oncology patients diagnosed with and treated for incidental PE, have similar high rates of recurrent VTE, bleeding complications, and mortality, as compared with oncology patients who develop symptomatic PE.