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Abstract

Introduction: Acute Massive Pulmonary Embolism (AMPE) is defined as venous thromboembolism (VTE) with associated obstructive shock due to acute right ventricular failure. Previous studies have shown that 70% of patients expire within 1 hour of symptom onset. Given the clinical course, rapid diagnosis and risk stratification are critical. Little is known about the utility of right ventricular echocardiography (RVE) for risk stratification in AMPE. Hypothesis: We hypothesized that advanced RVE parameters would provide prognostic information in patients with AMPE. Methods: We retrospectively reviewed all Maine Medical Center discharge records of patients with PE occurring between January 2010 and June 2012 to obtain demographic and clinical data. RVE measurements were obtained by analysis of echocardiograms performed prior to VTE therapy at the time of AMPE initial presentation. Group differences were considered statistically significant at p < 0.05. This study was approved by the Maine Medical Center Institutional Review Board. Results: There were 287 patients with PE of which AMPE was diagnosed in 46 cases (16%). Cardiac arrest was the initial presentation in 19.5% of cases. Overall AMPE mortality was 39.1% with a median time from shock to death of 19.9 hrs. Risk of death was associated with older age (65 vs 57 yrs; p = 0.013) and absence of limb symptoms (RR = 3.5; p = 0.049). Echocardiograms were of adequate quality to obtain RV size and functional parameters in 34 cases. Risk of death was associated with higher tricuspid regurgitation velocity (4.1 vs 2.9 m/s; p = 0.001), higher RV systolic pressure (79.5 vs 45.4 mmHg; p = 0.001) and higher RV/LV diastolic area ratio (2.38 vs 1.04; p = 0.013). Reduced risk of death was associated inferior vena cava (IVC) filter placement (RR = 0.51; p = 0.013). Conclusions: We found AMPE has a rapid clinical course and high mortality. Bedside RVE measurements of TRV, RVSP, and RV/LV diastolic area ratio obtained before VTE therapy have prognostic value in AMPE patients. IVC filter placement may help to reduce overall AMPE mortality. Early bedside RV echocardiography may be of utility in therapeutic decision making.