Prognostic significance of computed tomography-assessed right ventricular enlargement in low-risk patients with pulmonary embolism: Systematic review and meta-analysis

Background: For patients with acute low-risk pulmonary embolism (PE), determined by a validated clinical prognostic score, the additive prognostic significance of computed tomography (CT)-assessed right ventricular (RV) enlargement is uncertain. Methods: We performed a systematic review and meta-analysis of studies that enrolled patients with acute lowrisk PE to assess the prognostic value of concomitant CT-assessed RV enlargement for 30-day all-cause mortality and PE-related death. We conducted unrestricted searches of PubMed and Embase through December 2019. We used a random-effects model to pool study results; Begg rank correlation method to evaluate for publication bias; and I-2 testing to assess for heterogeneity. Results: Of the 7 cohorts with 2197 participants who had low-risk PE and provided results on the primary outcome, 743 (34%; 95% confidence interval [CI], 32-36%) patients had concomitant RV enlargement. Six of 743 (0.8%; 95% CI, 0.3-1.8%) patients with concomitant RV enlargement died 30-days after the diagnosis of PE compared with 3 of 1454 (0.2%, 95% CI, 0-0.6%) without RV enlargement. CT-assessed RV enlargement did not have a significant association with 30-day all-cause mortality (odds ratio [OR], 2.6; 95% CI, 0.7-9.4; I-2 = 0%; P = 0.15) or PE-related mortality (OR, 2.8; 95% CI, 0.7-12.1; I-2 = 0%; P = 0.16). Conclusions: CT-assessed RV enlargement occurs in a third of PE patients identified as low-risk by clinical scores. Mortality rate in these patients is low, and CT-assessed RV enlargement was not associated with a significantly increased risk of death within 30 days of PE diagnosis.