A striking image of spontaneous echo contrast in severe mitral stenosis in a patient with good international normalised ratio (INR) control

Daniel A. Jeffery, Guy Lloyd, Arjun K. Ghosh

A 38 year old man was referred to our valve clinic for assessment. He had been diagnosed with untreated rheumatic mitral stenosis (MS) in 2009. He was diagnosed with atrial fibrillation in 2016 [on warfarin with good INR control]. Transthoracic echocardiography demonstrated severe MS. A large amount of spontaneous echo contrast (SEC) was noted in the severely dilated left atrium and a transoesophageal echocardiogram (TOE) was requested for further assessment of the MS (Image 1 and Videos 1-3). He was symptomatic with shortness of breath and reduced exercise tolerance consistent with NYHA class III-IV. The extent of SEC (representing slow flowing blood) in a patient with an acceptable INR of 2.5 is striking. The AHA guidelines (1) and ESC guidelines (2) suggest managing rheumatic MS based on stenosis severity, symptoms and the presence of left atrial clot. In this case, following multidisciplinary team (MDT) discussion, a consensus decision was then made to offer him high-risk mitral valve replacement surgery. A 33mm Sorin mechanical mitral valve was thereafter implanted in an uncomplicated operation. The patient has been reviewed subsequently in clinic with a dramatic improvement in his symptoms. Repeat echocardiography demonstrated a well-functioning valve and resolution of SEC. The learning point in this case is that that having a therapeutic INR does not necessarily stop significant SEC from being observed on echocardiography, especially if there are important contributory factors, such as severe MS. It is to be remembered that SEC is a marker of stasis and has been shown to occur due to (platelet-independent) RBC aggregation in sluggish, low-shear stress flow conditions (3).