Introduction
Mitral regurgitation (MR) stands as the most common valvular heart disease in developed countries and is a prevalent medical condition in the elderly, whereas 10% of patients aged 75 are affected (1). MR is categorized as primary and functional types founded on the straight or indirect engagement of mitral valve constituents (2). Several medical and interventional therapies have been proposed for patients with MR. However, interventional approaches, including surgery, valvular replacement therapy, and trans-catheter mitral valve repair, are first-line treatments for patients with severe MR (3, 4). Patients with MR can present with asymptomatic to severe forms. It is essential to accurately determine MR severity and schedule the time of surgery, whereas delaying the surgery of severe MR patients can result in left ventricular dysfunction (5). Noteworthy, reduced left ventricular ejection fraction also indicates a bad prognosis for patients with MR (6). Therefore, the time of accurate staging of MR severity is the state-of-art to prevent the deterioration of patients with MR.
Echocardiography is the commonly used and first-line diagnostic method for evaluating MR severity (7). However, for a more accurate determination of MR severity, using the combined imaging methods in the setting of quantitative, semi-quantitative, and qualitative modalities is recommended (8). Advanced imaging modalities like cardiac magnetic resonance imaging (CMR) and computed tomography (CT) scan are gradually increasing recently due to the providing complementary data and suboptimal findings of echocardiography, especially in patients requiring additional evidence for making clinical decisions (9). Besides, transesophageal echocardiography (TEE) has become widely used within the last two decades and has its own disadvantages, such as skill-dependent procedures, malfunction of the probe, and complications related to the long-term sedation of patients that make it inappropriate first-line modality (10). However, these recently developed modalities have disadvantages, such as high cost, requiring highly-skilled operators, and expensive devices, that make them not widely available in developing countries. Therefore, considering new parameters on the findings of traditional imaging modalities are essential to covering the gaps in these modalities and providing a more accurate staging of the MR severity. Here, we evaluated new echocardiographic parameters to assist more precise estimations of mitral regurgitation severity and to provide an accurate method to classify MR severity in transthoracic echocardiography (TTE).