DefinePK

Abstract

Secondary mitral regurgitation (MR) also known as the'functional' MR, is not primarily due to underlying valve pathology. It is due to left ventricular dysfunction either secondary to idiopathic dilated cardiomyopathy or due to underlying coronary artery disease (CAD). Regional or global left ventricular (LV) systolic dysfunction and adverse LV remodelling can cause restricted leaflet motion and failure of leaflet coaptation resulting in MR.1 Thus, the mechanism is largely ventricular rather than valvular. MR burdens the LV with a volume overload state that leads to a series of compensatory myocardial and circulatory adjustments. Eventually, the myocardium fails, the ventricle decompensates, and the patient exhibits signs of heart failure. It has been strongly associated with decreased quality of life, increased rate of hospitalization for heart failure, and shortened survival. 2,3  Hence, the prognosis among patients with heart failure and secondary mitral regurgitation is extremely poor associated with high mortality rates. In the remote past, the only option to treat secondary MR was to treat the underlying etiology. Guideline-directed medical therapy (GDMT) and cardiac resynchronization therapy (CRT) provided symptomatic relief, improved the left ventricular function, and in some patients, it lessened the severity of mitral regurgitation. 4 As correction of valve in case of primary MR improve outcomes, the contrary was not true in case of secondary MR as the valve was structurally normal. Hence, neither percutaneous or surgical repair nor surgical replacement of the mitral valve had shown to lower the rate of hospitalization or death associated with secondary mitral regurgitation. 4 Percutaneous repair by MitraClip is a transcatheter technology based on the surgical Alfieri edge-to-edge repair, which involves suturing together the middle segments of the anterior and posterior mitral valve leaflets, thereby creating a "double orifice" mitral regurgitant area. 4 The MitraClip system utilizes a cobalt chromium clip covered with a polypropylene fabric that grasps the leaflet and reduces mitral regurgitation (MR) by increasing the coaptation between the regurgitant valve leaflets. In some cases, a second clip may be required to adequately reduce the MR severity toward a goal of final regurgitant severity