Pulmonary embolism and mortality in patients with COPD

Background: Previous studies suggest that most patients with pulmonary embolism die of their underlying diseases and pulmonary embolism is itself responsible for a minority of deaths. It has not been determined whether pulmonary embolism is associated with increased mortality among patients with different specific diseases. Methods: We assessed the mortality in 1,487 patients who had lung scans to pursue the diagnosis of pulmonary embolism. An outcome classification committee prospectively reviewed deaths occurring up to 1 year after each patient's entry into the study. Results: Ninety-five (23.8%) patients with pulmonary embolism and 189 (18.9%) without pulmonary embolism died within 1 year of study entry (estimated relative risk, 1.34; 95% confidence interval, 1.01 to 1.79). Mortality according to pulmonary embolism status was different among patients with COPD from mortality among patients who did not have COPD (interaction p=0.03). Of 45 patients with COPD and pulmonary embolism, 24 (53.3%; 95% confidence interval, 38.8 to 67.9%) died within 1 year. After adjustment for patient characteristics, the estimated risk of dying within 1 year was 1.94 times (95% confidence interval, 1.17 to 3.24) for patients with COPD and pulmonary embolism compared with those without pulmonary embolism, and 1.14 (95% confidence interval, 0.85 to 1.54) for patients without COPD (interaction p=0.08). Conclusions: Patients with COPD and pulmonary embolism have an increased 1-year mortality. Further study is needed to clarify the reason(s) for the increase in mortality.