Need for Transthoracic Echocardiogram in Patients with Low-Risk Pulmonary Thromboembolism: A Systematic Review and Meta-Analysis. / Necesidad de una ecocardiografía transtorácica en pacientes con tromboembolia de pulmón de riesgo bajo: revisión sistemática y metanálisis.

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.

Assessment of coexisting deep vein thrombosis for risk stratification of acute pulmonary embolism.

BACKGROUND: In patients with acute pulmonary embolism (PE), studies have shown an association between coexisting deep vein thrombosis (DVT) and short-term prognosis. It is not known whether complete compression ultrasound testing (CCUS) improves the risk stratification of their disease beyond the recommended prognostic models. METHODS: We included patients with normotensive acute symptomatic PE and prognosticated them with the European Society of Cardiology (ESC) risk model for PE. Subsequently, we determined the prognostic significance of coexisting DVT in patients with various ESC risk categories. The primary endpoint was a complicated course after the diagnosis of PE, defined as death from any cause, haemodynamic collapse, or adjudicated recurrent PE. RESULTS: According to the ESC model, 37% of patients were low-risk, 56% were intermediate-low risk, and 6.7% were intermediate-high risk. CCUS demonstrated coexisting DVT in 375 (44%) patients. Among the 313 patients with low-risk PE, coexisting DVT (46%) did not show a significant increased risk of complicated course (2.8%; 95% confidence interval [CI], 0.8%-7.0%), compared with those without DVT (0.6%; 95% CI, 0%-3.2%), (P = 0.18). Of the 478 patients with intermediate-low risk PE, a complicated course was 14% and 6.8% for those with and without DVT, respectively (P = 0.01). Of the 57 patients that had intermediate-high risk PE, a complicated course occurred in 17% and 18% for those with and without DVT, respectively (P = 1.0). CONCLUSIONS: In normotensive patients with PE, testing for coexisting DVT might improve risk stratification of patients at intermediate-low risk for short-term complications.

Impact of obstructive sleep apnea on cardiovascular outcomes in patients with acute symptomatic pulmonary embolism: Rationale and methodology for the POPE study.

In normotensive patients with acute symptomatic pulmonary embolism (PE), the effect of undiagnosed obstructive sleep apnea (OSA) on cardiovascular (CV) outcomes lacks clarity. The Prognostic Significance of Obstructive Sleep Apnea in Patients With Acute Symptomatic Pulmonary Embolism (POPE) study is a multicenter, observational study designed to prospectively assess the prognostic significance of concomitant OSA in hemodynamically stable outpatients with acute symptomatic PE. Adult patients with acute stable PE are eligible. Recruited patients undergo an overnight sleep study using a level III portable diagnostic device within 7 days (and preferably within 48 hours) of diagnosis of PE. The sleep tracings are analyzed by a certified sleep technologist and audited by a sleep physician, both of whom are blinded to other study data. The patients are divided into 2 groups based on apnea-hypopnea index (AHI): OSA (AHI ≥15) and non-OSA (AHI <15) groups. The study uses a composite of PE-related death, CV death, clinical deterioration requiring an escalation of treatment, or nonfatal CV events (recurrent venous thromboembolism, acute myocardial infarction, or stroke) within 30 days after the diagnosis of PE as the primary outcome. The projected sample size of 225 patients will provide 80% power to test the hypothesis that OSA will increase the primary outcome from 7% in the non-OSA group to 20% in the OSA group, with α ≤0.05. The trial results will be important to understand the burden and CV effects of OSA in PE patients.