About 6% of patients with chronic obstructive pulmonary disease (COPD) who are admitted to the hospital with worsening respiratory symptoms will have pulmonary embolism, new research from France suggests.

How often pulmonary embolism occurs in this patient population remains unclear, Dr. Francis Couturaud from Cavale Blanche Hospital, in Brest, and colleagues note in JAMA.

To investigate, they did a cross-sectional study of 740 consecutive COPD patients admitted to seven French hospitals for deteriorating respiratory function. Their mean age was 68.2 years and 37% were women.

All patients were systematically screened for pulmonary embolism using a predefined pulmonary embolism diagnostic algorithm based on Geneva score, D-dimer levels, and spiral computed tomographic pulmonary angiography plus leg compression ultrasound.

Among all 740 patients, 44 (5.9%) had pulmonary embolism confirmed within 48 hours of admission. An additional 10 patients (1.4%) had an isolated deep vein thrombosis.

The prevalence of pulmonary embolism reached 10% when it was suspected (30 of 299 patients) and remained at more than 3% among patients without a clinical suspicion (14 of 441 patients).

The key secondary outcome was pulmonary embolism occurring during the three-month follow-up period among patients who did not have venous thromboembolism at admission and did not receive anticoagulant treatment. Among the 670 patients in this group, five developed pulmonary embolism (0.7%) during follow-up, and three died.

"Because all pulmonary embolism events were adjudicated and confirmed by an independent clinical events committee using predefined, standardized, and validated criteria, this study provides a valid and reliable prevalence estimate of pulmonary embolism in this setting," the researchers say.

How and when patients admitted to the hospital for an acute COPD exacerbation should be screened for pulmonary embolism "remains challenging," the authors note.

"Well-established diagnostic management of suspected acute pulmonary embolism in the general population might be ineffective in the setting of COPD exacerbations, particularly when including a ventilation-perfusion lung scan. Furthermore, the clinical presentation of acute pulmonary embolism and COPD exacerbation are similar, making it difficult to determine whether pulmonary embolism should be suspected in this context," they point out.

"Further research is needed to understand the possible role of systematic screening for pulmonary embolism in this patient population," they conclude.

Dr. Couturaud did not respond to a request for comment by press time.

SOURCE: https://bit.ly/3pPCLsF JAMA, online January 5, 2021.