A diagnostic workup for pulmonary embolism (PE) should be performed in all patients with recent onset of exertional dyspnea, according to the authors of an article published in the Journal of Thrombosis and Haemostasis. That conclusion emerged from an analysis of PE prevalence in 417 patients with recent marked exertional dyspnea performing previously well-tolerated physical activities.
Exertional dyspnea is a frequently encountered complaint in clinical practice. Missteps in both diagnosis and early management, however, have been found to be prevalent in emergency department practices. with a complicated clinical course or mortality as a consequence, stated the researchers. Also, failure to diagnose PE is a common malpractice allegation.
Noting that the prevalence of PE among patients with dyspnea on exertion has not been reported, the authors hypothesized: “PE might be a frequent underlying condition in patients presenting for care complaining of marked dyspnea on exertion of recent onset.”
In a multicenter prospective, cross-sectional study among 14 university or hospital centers in Italy, patients who were referred for outpatient evaluation with recent (< 1 month) dyspnea on exertion with a severity of 3 or 4 on the modified Medical Research Council dyspnea scale were potentially eligible for the study. Prior deep-vein thrombosis (DVT), PE, and use of therapeutic anticoagulation were among exclusion criteria. All patients aged 75 years or younger with recent (< 1 month) marked exertional dyspnea had a systematic workup for PE, irrespective of concomitant signs or symptoms of venous thromboembolism and alternative explanations for dyspnea. The main study outcome was prevalence of PE in the entire cohort of patients with recent marked dyspnea on exertion.
When about 400 patients had been enrolled after an interim analysis in which the preestablished stopping rule (if the lower limit of the 95% confidence interval of the prevalence of PE exceeds 20%) was met, the study was prematurely terminated. PE was found, after exclusion of 134 patients based on low PE clinical probability and normal D-dimer, in 134 (47.3%) of the remaining 283 patients. The overall PE prevalence was 32.1% (95% confidence interval, 27.8-36.8).
PE was present in 40 of 204 (19.6%) patients without other findings suspicious for PE and in 94 of 213 patients (44.1%) with PE-suspicious findings. PE involved a main pulmonary artery in 37% and multiple lobes in 87% of the patients.
The researchers pointed out that, while the prevalence of PE was highest (44%) in patients who had concomitant signs or symptoms suspicious of PE or underlying DVT, PE was detected in almost 20% of patients without concomitant PE signs and symptoms. Also, the detected pulmonary emboli were deemed significant.
“Our findings suggest that, regardless of the diagnostic algorithm in use, physicians should rule in or out PE in patients who solely report recent onset of marked dyspnea on exertion,” they concluded.
Agreeing with the authors’ conclusions, Mary Jo S. Farmer, MD, PhD, of the department of medicine at University of Massachusetts, Worcester, stated in an interview, “The results of the current study support a diagnostic workup for pulmonary embolus in all patients with recent onset of exertional dyspnea.” She added, “Pulmonary emboli detected were significant as almost all were segmental or more proximal emboli involving multiple lobes. The observed overall prevalence of pulmonary embolus of 32% may seem high when compared with the low prevalence of 7%-13% reported in other studies of patients with suspected pulmonary embolus. However, the prevalence of pulmonary embolus among emergency department cohorts in European countries is generally higher, as is the diagnostic yield from [CT pulmonary angiogram] compared to North American countries. This could be explained by differences in applied thresholds for suspicion of pulmonary embolus. The incidence of COVID-19 and association with thrombosis was not reported.
“It has been reported that nonspecific clinical manifestations and absence of typical signs and symptoms can result in delay in diagnosis of pulmonary embolus or result in pulmonary embolus being missed, an unfortunate situation that could result in malpractice allegation.” Dr. Farmer concluded.
Among limitations of the study, the authors noted that their results are not applicable to patients older than 75 years or patients with chronic (more than 1 month) symptoms of dyspnea or less severe dyspnea (modified Medical Research Council dyspnea score of 2 or lower). Also, no attempt to stratify the clinical relevance of PE was made.
The study was funded by the Arianna Foundation on Anticoagulation, Bologna, Italy. The authors reported that they had no potential conflicts. Dr. Farmer also declared she had no relevant conflicts.