Transthoracic Echocardiography and Chest Computed Tomography Arteriography in Patients with Acute Pulmonary Embolism: A Two-Year Follow-Up Study

Background: Pulmonary hypertension (PH) is frequently found at the time of diagnosis of pulmonary embolism (PE). An incomplete resolution of PE can lead to chronic thromboembolic pulmonary hypertension (CTPH). Transthoracic echocardiogram (TTE) is the first step to diagnose an abnormality of the pulmonary vasculature. Based on computed tomography (CT), the Qanadli vascular obstruction index has been extensively used to assess acute PE. Objectives: Our aim was to ascertain whether at the time of diagnosis of an acute PE episode TTE variables and a Qanadli CT index score may be associated with CTPH 2 years later. Method: Patients with PE were prospectively enrolled. TTE was performed and the Qanadli CT obstruction index was calculated on admission to the hospital, while only TTE was repeated at the 2-year follow-up. The NYHA (New York Heart Association) functional classification was evaluated. Correlation analyses were performed. Results: Twenty patients (11 males, median age 69.5 years) were considered for the study. There was no significant correlation between TTE parameters and the Qanadli CT obstruction index. A significant distribution (χ2 = 5.69, p = 0.017) was found in the analysis among patients with CTPH at 24 months and the Qanadli CT index, categorized by a receiver operating characteristic curve cutoff value of 42.5%. Additionally, a significant distribution (χ2 = 4.09, p = 0.043) was found in the analysis among patients with CTPH at 24 months and right ventricular systolic pressure on admission, categorized as PH (>31 mm Hg). Conclusion: Our study demonstrates that in patients with acute PE there is no relationship between the Qanadli CT obstruction index and TTE parameters on admission to the hospital. However, the occurrence of CTPH at the 24-month follow-up is associated with PH and with a high Qanadli CT obstruction index score.