Introduction: Chronic obstructive pulmonary disease (COPD) is a frequent disease affecting mainly the elderly and males. Dyspnea is the most common reason for consultation for patients with COPD in ER. Distinguishing between pulmonary and/or cardiac origin can be challenging, hence the interest of ultrasound and in particular the study of the collapsibility index of the inferior vena cava (ΔIVC).

Objective:  To determine the value of the ΔIVC in the diagnosis of heart failure (HF) patients with acute exacerbation of COPD (AECOPD).

Methods: This is a prospective study conducted in the ED of three Tunisian university hospitals: Fattouma Bourguiba Monastir, Sahloul Sousse, and Farhat Hached Sousse from January 2022 to Mars 2022 including patients with AECOPD. During this period, 401 patients met the inclusion criteria. The final diagnosis of HF is based on the opinion of two emergency experts after consulting the data from the clinical examination, cardiac echocardiography, and BNP level. The ΔIVC was calculated by Two experienced emergency physicians who were blinded from the patient’s clinical and laboratory data, using the formula: (IVC max-IVC min) / IVC min x 100. A cut off of 15% was used to define the presence (<15%) or absence of HF (≥15%). The left ventricular ejection fraction (LVEF) is also measured (cut-off preserved/reduced).

Results: The study population is relatively elderly with an average age of 67.2 years, predominantly male (68.9%) and characterized by heavy comorbidity and cardiopulmonary risk factors. . The patients were divided into two groups according to the final diagnosis of HF; 165 patients (41.1%) had a final diagnosis of HF (HF group) and 236 patients (58.9%) without HF (non HF group). Patients in the HF group had more comorbidities with higher rates of hypertension (p=0.001), chronic HF (CHF), coronary artery disease, and diabetes. The assessment of the performance of the ΔIVC in the diagnosis of HF showed a sensitivity of 37.4% and a specificity of 89.7% using the threshold of 15%, which appears to be associated with the best diagnostic performance; the positive predictive value is 70.9% and the negative predictive value is 66.7%. The area under the ROC curve is 0.71(95%, CI 0.65 – 0.76). ΔIVC values were not different between HF patients with reduced LVEF (LVrEF) and those with preserved LVEF (LVpEF)

Conclusion: Our main results show that the ΔIVC has a good value for ruling out HF in COPD patients consulting emergency rooms for acute dyspnea.