Need for Transthoracic Echocardiogram in Patients with Low-Risk Pulmonary Thromboembolism: A Systematic Review and Meta-Analysis.

INTRODUCTION:It is unclear whether low-risk patients with acute symptomatic pulmonary embolism (PE) should undergo echocardiogram. METHODS:We performed a meta-analysis of studies that enrolled patients with acute low-risk PE to assess the prognostic value of echocardiographic diagnosis of right ventricular (RV) dysfunction for the primary outcome of short-term all-cause mortality, and the secondary outcome of short-term PE-related mortality. We used a random-effects model to pool study results, a Begg rank correlation method to evaluate for publication bias, and I2 testing to assess heterogeneity. RESULTS:The meta-analysis included a total of 11 studies 1,868 patients with low-risk PE. Ten of the 447 (2.2%; 1.1%-4.1%) low-risk patients with echocardiographic RV dysfunction died soon after the diagnosis of PE compared with 10 of 1,421 (0.7%; 0.3-1.3%) patients without RV dysfunction. RV dysfunction was not significantly associated with short-term all-cause mortality (odds ratio 2.0; 95% confidence interval, 0.8-5.1, p=.14; I2=8%). RV dysfunction was significantly associated with short-term PE-related mortality (odds ratio 5.2; 95% confidence interval, 1.7-16, p <.01; I2=0%). CONCLUSIONS:In patients with low-risk PE, echocardiographic RV dysfunction is not associated with all-cause mortality, but identifies patients with an increased risk for short-term PE-related mortality.