Right ventricular function and thrombus load in patients with pulmonary embolism and diagnostic delay

A systematic review and meta-analysis of diagnostic delay in pulmonary embolism

Background

Diagnostic delay in patients with pulmonary embolism (PE) is typical, yet the proportion of patients with PE that experienced delay and for how many days is less well described, nor are determinants for such delay.

Objectives

This study aimed to assess the prevalence and extent of delay in diagnosing PE.

Methods

A systematic literature search was performed to identify articles reporting delays in diagnosing PE. The primary outcome was mean delay (in days) or a percentage of patients with diagnostic delay (defined as PE diagnosis more than seven days after symptom onset). The secondary outcome was determinants of delay. Random-effect meta-analyses were applied to calculate a pooled estimate for mean delay and to explore heterogeneity in subgroups.

Results

The literature search yielded 10,933 studies, of which 24 were included in the final analysis. The pooled estimate of the mean diagnostic delay based on 12 studies was 6.3 days (95% prediction interval 2.5 to 15.8). The percentage of patients having more than seven days of delay varied between 18% and 38%. All studies assessing the determinants of coughing (n = 3), chronic lung disease (n = 6) and heart failure (n = 8) found a positive association with diagnostic delay. Similarly, all studies assessing recent surgery (n = 7) and hypotension (n = 6), as well as most studies assessing chest pain (n = 8), found a negative association with diagnostic delay of PE.

Conclusion

Patients may have symptoms for almost one week before PE is diagnosed and in about a quarter of patients, the diagnostic delay is even longer.

The problem of under-diagnosis and over-diagnosis of pulmonary embolism

Pulmonary embolism (PE) is an increasingly recognised condition which is associated with significant morbidity and mortality. Despite the better awareness of this serious condition, the diagnosis is still overlooked in many cases with sometimes fatal consequences. Under-diagnosis may be due to several reasons including reliance on non-specific 'classic' symptoms, belief that bedside measurements will likely be abnormal in the setting of acute PE, and confounding factors like co-existent cardiorespiratory diseases or being in an intensive care unit, where the diagnosis may not be considered. At the same time, incidental diagnosis of PE is occurring more often due to frequent use of imaging investigations alongside advancements in CT technology, and dilemma exists as to whether the chance finding of PE requires anticoagulation, especially when identified only at the subsegmental level. This article reviews these two issues of under-diagnosis and over-diagnosis of PE in the current era.

Determinants and prognostic implication of diagnostic delay in patients with a first episode of pulmonary embolism

Signs and symptoms of pulmonary embolism (PE) are not specific and this can lead to a diagnostic delay. Little is known about the determinants of this delay and its prognostic implication. We conducted a retrospective analysis of a prospective cohort involving 514 patients with a first episode of PE. The diagnostic delay was defined as a time from first symptom onset to diagnosis of >3 days, corresponding of the median time in the population. Multivariable logistic regression analysis was performed to identify determinants of diagnostic delay. Prognostic implication was measured as the occurrence of 30-day all-cause mortality, haemodynamic collapse or recurrent PE. A total of 240 (47%) among 514 patients had a time from first symptom to diagnosis > 3 days. Previous deep vein thrombosis (OR 0.55, 95% Confidence Interval (CI), 0.32-0.93), immobilization (OR 0.52, 95% CI, 0.28-0.96), surgery (OR 0.31, 95% CI, 0.16-0.62), chest pain (OR 0.58, 95% CI, 0.39-0.86), syncope (OR 0.48, 95% CI, 0.23-1.01), dyspnea (OR 2.48, 95% CI, 1.57-3.91) and hemoptysis (OR 3.57, 95% CI, 1.40-9.07) were associated with diagnostic delay. Twenty-two patients (4.3%, 95%CI, 2.8-6.5) experienced an outcome event within 30 days. Among them, 15 patients (6.2% 95%CI, 3.7-10.3) had a diagnostic delay and 7 (2.6%, 95% CI 1.1-5.4) did not (p = 0.039). In this cohort, diagnostic delay is associated with the absence of major risk factors for PE or clinical features such as chest pain or syncope and the presence of dyspnea or hemoptysis. Diagnostic delay is associated with a worse 30-day prognosis.