Background: In patients with acute symptomatic pulmonary embolism (PE), embolic burden has an uncertain prognostic significance.
Methods: We performed a meta-analysis of studies including patients with PE to assess the prevalence and prognostic relevance of central PE (i.e., saddle or main pulmonary emboli) for short-term death and other adverse outcome events. A random-effects model was used to pool study results, and I2 testing was used to test for heterogeneity.
Results: Data from 28 studies (205,877 patients) were included in the analysis. Of the 26 studies with 205,410 participants that enrolled consecutive patients with PE, 7,748 (3.8%) had central PE. Though there was no statistically significant difference between central and noncentral PE for odds of short-term all-cause mortality (odds ratio [OR] 1.19; 95% confidence interval [CI], 0.91 to 1.55), central PE had a significant association with short-term PE-related deterioration or death (OR, 2.47; 95% CI, 1.44 to 4.25). Results from 9 studies with 4,325 PE patients that had available data showed that central PE had a significant association with the odds of short-term PE-related mortality (OR, 1.77; 95% CI, 1.22-2.55). Results were consistent for prospective (OR, 1.67; 95% CI, 1.21 to 2.32), and studies that only enrolled stable patients (OR, 1.42; 95% CI, 1.06 to 1.92).
Conclusions: Central PE was an uncommon finding in unselected patients diagnosed with PE. While central thrombus did not have an association with increased risk of all-cause mortality, it was significantly associated with an increased risk of PE-related deterioration and death short after diagnosis.
