For patients diagnosed with acute pulmonary embolism (PE), the prognostic significance of concomitant right heart thrombi (RHT) lacks clarity.
We performed a meta-analysis of studies that enrolled patients with acute PE to assess the prognostic value of echocardiography-detectable RHT for the primary outcome of short-term all-cause mortality, and the secondary outcome of short-term PE-related mortality. We conducted unrestricted searches of Pubmed and Embase from 1980 through January 31, 2016 and used the terms “right heart thrombi”, “pulmonary embolism”, and “prognos*”. We used a random-effects model to pool study results; Begg rank correlation method to evaluate for publication bias; and I2 testing to assess for heterogeneity.
Six of 79 potentially relevant studies met inclusion criteria (15,220 patients). Overall, 99 of 593 patients with echocardiography-detectable RHT died (16.7%; 95% CI, 13.8% to 19.9%) compared with 639 of 14,627 without RHT (4.4%; 95% CI, 4.0% to 4.7%). RHT had a significant association with short-term all-cause mortality in all patients (odds ratio [OR], 3.0; 95% CI, 2.2 to 4.1; I2 = 20%), and with PE-related death (3 cohorts, 12,955 patients; OR, 4.8; 95% CI, 2.0 to 11.3; I2 = 76%). Results were consistent for prospective (2 cohorts, 514 patients; OR, 4.8; 95% CI, 1.7 to 13.6; I2 = 56%) or retrospective studies (4 cohorts, 14,706 patients; OR, 2.8; 95% CI, 2.1 to 3.8; I2 = 0%).
In patients diagnosed with acute PE, concomitant RHT were significantly associated with an increased risk of death within 30 days of PE diagnosis.