Mitral regurgitation as a complication of ischaemic heart disease: the future is echo

Functional mitral regurgitation is a common complication of ischaemic heart disease (Jorapur, 2005). Mitral valve repair in patients with moderate ischaemic mitral regurgitation during coronary artery bypass grafting significantly improves patient outcomes when assessed by functional criteria such as peak oxygen consumption, exercise tolerance or New York Heart Association class (Fattouch, 2009; Chan et al., 2012), but not when judged only in terms of survival rates and rates of major adverse cardiac and cerebrovascular events over a relatively short time period (Michler et al., 2016). It is likely that longer time frames are required for impacts on mortality to be observed.

In the meantime, until long term improvements of patient mortality and morbidity are proven, the issue remains sufficiently contentious that there has been no lowering of the threshold for indication of mitral valve repair for ischaemic mitral regurgitation in the guidelines (Nishimura et al. (2017); Grayburn et al. (2017)). Contributing to the debate is the relatively high (>50%) recurrence of significant mitral regurgitation within two years of mitral annuloplasty in some studies (Goldstein et al., 2016).

This issue is further convoluted by the fact that there remains considerable heterogeneity in the criteria used in annuloplasty ring selection, which may account for much of the variability between and even within different centres. Creating a standardised and reproducible method for accurate annuloplasty ring sizing is therefore becoming more important than ever in moving the debate forward and, very likely, in improving outcomes (Bothe et al., 2013). With improvements in imaging quality and capability – particularly 3D transthoracic and transoesophageal echo – it is likely that this is a problem that echocardiography may be able to tackle in the near future.