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).