Does Implementation of a Pulmonary Embolism Diagnostic Strategy Yield Benefits in COPD?

Adding an active strategy for the diagnosis of pulmonary embolism (PE) to usual care did not significantly improve a composite health outcome among those hospitalized for exacerbation of chronic obstructive pulmonary disease (COPD) compared with usual care alone, according to results of a randomized clinical trial. Findings were published in JAMA.

PE is common among patients with COPD exacerbations, although the condition’s diagnosis based on clinical suspicion is not sufficiently accurate, the authors explained. To address this uncertainty, use of CT pulmonary angiogram (CTPA) in emergency departments has increased in recent years.

However, “CTPA is a time-consuming and burdensome investigation associated with radiation exposure, contrast reactions, and high cost,” they said. “In addition, the need for an active detection strategy for PE needs to be balanced against the risk of exposing additional patients to anticoagulation, because the diagnosis may not always have clinical significance.”

To assess whether an active search for PE improves clinical outcomes in these patients, researchers conducted the Significance of Pulmonary Embolism in COPD Exacerbations (SLICE) multicenter randomized trial.

Between 2014 and 2020, patients with COPD exacerbations who required hospital admission were randomized 1:1 to undergo an active search for PE, using D-dimer test and CTPA, or to receive usual care. Individuals were recruited from 18 centers across Spain.

Standard clinical management typically consisted of supplemental oxygen, short-acting inhaled β2 agonists and short-acting anticholinergic agents, systemic corticosteroids, antibiotics, and pharmacological thromboprophylaxis, the researchers wrote. All D-dimer tests were conducted within 12 hours of randomization. Those with a negative value were deemed free of PE, and those with positive values underwent CTPA.

If PE was confirmed, patients received anticoagulant treatment. Primary outcome composites (nonfatal new or recurrent symptomatic venous thromboembolism [VTE], readmission for COPD, or death) were assessed within 90 days.

A total of 746 individuals were randomized, of whom 737 completed the trial; the mean (SD) patient age was 70.4 (9.9) years and the majority (74%) were male.

Analyses revealed:

• The primary outcome occurred in 110 patients (29.7%) in the intervention group and 107 patients (29.2%) in the control group (absolute risk difference, 0.5%; 95% CI, −6.2% to 7.3%; relative risk, 1.02; 95% CI, 0.82-1.28; P = .86)
• Nonfatal new or recurrent VTE was not significantly different in the 2 groups (0.5% vs 2.5%; risk difference, −2.0%; 95% CI, −4.3% to 0.1%)
• By day 90, 94 patients (25.4%) in the intervention group and 84 (22.9%) in the control group had been readmitted for exacerbation of COPD (risk difference, 2.5%; 95% CI, −3.9% to 8.9%)
• Death from any cause occurred in 23 patients (6.2%) in the intervention group and 29 (7.9%) in the control group (risk difference, −1.7%; 95% CI, −5.7% to 2.3%)
• Major bleeding occurred in 3 patients (0.8%) in the intervention group and 3 patients (0.8%) in the control group (risk difference, 0%; 95% CI, −1.9% to 1.8%; P = .99)

The observed frequency of PE in the intervention group was lower than anticipated, marking a limitation to the study, while the trial was also not powered to show a possible favorable difference in new or recurrent VTE or all-cause mortality, the authors concluded.

Reference

Jiménez D, Agustí A, Tabernero E, et al. effect of a pulmonary embolism diagnostic strategy on clinical outcomes in patients hospitalized for COPD exacerbation: a randomized clinical trial. JAMA. Published online October 5, 2021. doi:10.1001/jama.2021.14846