Re-Appraisal of Echocardiographic Assessment in Patients with Pulmonary Embolism: Prospective Blinded Long-Term Follow-Up.

Background: Acute pulmonary embolism (PE) is considered to be one of the most common cardiovascular diseases with considerable mortality. Conflicting data imply possible role for echocardiography in assessing this disease.

Objectives: To determine which of the echo parameters best predicts short-term and long-term mortality in patients with PE.

Methods: We prospectively enrolled 235 patients who underwent computed tomography of pulmonary arteries (CTPA) and transthoracic Echocardiography (TTE) within < 24 hours. TTE included a prospectively designed detailed evaluation of the right heart including right ventricular (RV) myocardial performance index (RIMP), RV end diastolic and end systolic area, RV fractional area change, acceleration time (AT) of pulmonary flow and visual estimation. Interpretation and performance of TTE were blinded to the CTPA results.

Results: Although multiple TTE parameters were associated with PE, all had low discriminative capacity (AUC < 0.7). Parameters associated with 30-day mortality in univariate analysis were acceleration time (AT) < 81 msec (P = 0.04), stroke volume < 44 cc (P = 0.005), and RIMP > 0.42 (P = 0.05). The only RV independent echo parameter associated with poor long-term prognosis (adjusted for significant clinical, and routine echo associates of mortality) was RIMP (hazard ratio 3.0, P = 0.04). The only independent RV echo parameters associated with mortality in PE patients were RIMP (P = 0.05) and AT (P = 0.05). Addition of RIMP to nested models eliminated the significance of all other parameters assessing RV function.

Conclusions: Doppler-based parameters like pulmonary flow AT, RIMP, and stroke volume, have additive value in addition to visual RV estimation to assess prognosis in patients with PE.