Mortality risk in chronic obstructive pulmonary disease patients with pulmonary embolism (PE) is significantly higher than those without, reveals a recent analysis of case studies and controlled trials. More importantly, the analysis also found that the prevalence of PE — a blockage in one of the pulmonary arteries in the lungs caused by blood clots that travel to the lungs from deep veins in the legs– in patients with acute exacerbation of COPD is 12 percent or more. The researchers said that they analysed MEDLINE, the Cochrane Central Register of Controlled Trials, and Embase (a biomedical and pharmacological bibliographic database) including 16 studies and 4093 patients in total, to find the prevalence of PE in COPD patients with acute exacerbation (AE). The findings of the close link between AE COPD and PE in increased mortality risk suggests the necessity to develop validated diagnostic strategies for identifying PE in COPD patients with acute exacerbations.