Prospective Evaluation of the Prevalence of Pulmonary Embolism in Patients with Chronic Obstructive Pulmonary Disease Exacerbation: Challenges and Feasibility

Introduction: Data on the prevalence of pulmonary embolism (PE) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in North America is lacking, with most of the prospective studies conducted in Europe and Asia. The aim of this study is to describe feasibility of prospective collection of data evaluating the prevalence of PE in patients admitted for AECOPD in Canada, and to describe challenges of this approach.

Methods: This is a secondary analysis of a prospective pilot patient cohort aiming to assess the diagnosis of AECOPD among hospitalized patients. Items of the Wells PE and revised Geneva scores were prospectively collected. All patients underwent D-dimer testing within 24 hours of admission. All patients were followed for 3 months. Feasibility outcomes were prospective data collection to evaluate the prevalence of PE, D-dimer level measurement and 3-month follow-up. The study was considered feasible if >=90% of the patients had prospective data collected to assess the prevalence of PE, >=80% of the patients had D-dimer level measured and their 3-month follow-up, respectively. Challenges were also assessed.

Results: Twenty patients were included. According to the Wells PE score, 16 (80.0%), 4 (20.0%) and 0 (0.0%) patients had low, moderate and high clinical pre-test probability (c-PTP), respectively. According to the revised Geneva score, 2 (10.0%), 17 (85.0%) and 1 (5.0%) patients had low, intermediate and high c-PTP, respectively. Based on age-adjusted D-dimer cut-off, 7 and 11 patients had negative and positive D-dimer, respectively. All patients (100.0%) had prospective data collection to assess the prevalence of PE. D-dimer level was available for 18/20 (90.0%) patients and 3-month follow-up evaluation was performed in 16/20 (80.0%) patients. Challenges included the difficulty in recruiting patients since it is a population with many comorbidities, adequate c-PTP assessment using validated clinical decision rules, absence of consistent PE diagnostic strategy use since patients were mostly investigated according to the physician's impression and adequate 3-month follow-up since 25% of the patients had some protocol deviation for the follow-up. No PE was diagnosed during the entire study period.

Conclusion: This pilot study shows the feasibility in prospectively collecting data to evaluate the prevalence of PE in patients admitted for AECOPD in Canada. Also, challenges were assessed and included recruitment of patients, adequate c-PTP assessment, consistent PE diagnostic strategy use and adequate 3-month follow-up.

Le Gal:BMS-Pfizer: Research Funding; Pfizer, Sanofi, Aspen Pharma: Honoraria.