A vivid debate surrounds the management of the asymptomatic patient with significant mitral regurgitation (MR), a frequent problem in day-to-day cardiology.
Prof.J.F.Avierinos from Marseille, France, started the session reviewing echo quantitation of mitral regurgitation. The valve anatomy should be assessed thoroughly by 2D echo before any color Doppler examination: severe pathology by itself indicates severe MR. After this, focus should be on the proximal convergence zone rather than color jet area, first qualitatively and then quantitatively to calculate effective regurgitant area (ERO). The speaker made a strong recommendation to use quantitative parameters such as ERO and regurgitant volume, according to him "in every echo report" for such patients.
Prof.Luc Pierard, from Liege, Belgium, has published several landmark papers on the use of exercise echo to diagnose changes in the severity of ischemic MR with exercise. He pointed out that the use of exercise (not dobutamine stress !) echo adds crucial information in many scenarios. In organic MR, exercise echo determines whether there is contractile reserve (an increase in ejection fraction and a decrease in systolic left ventricular volume). If contractile reserve is present, the patient usually can be managed conservatively. In ischemic MR, severity can increase substantially with exercise; there is no relation between resting severity and exercise severity. Unpublished data indicate that this may also be true for many patients with organic MR. L.Pierard therefore called for routine exercise echo examinations in asymptomatic patients with severe or moderate MR, in whom surgery is considered, to test both the ventricle and the valve in terms of ERO changes.
Dr.M.Enriquez-Sarano, Rochester, USA, discussed "criteria for surgical treatment". In organic mitral regurgitation, he strongly - and provocatively - advocated early operation even in asymptomatic patients with severe organic mitral regurgitation (ERO > 40 mm2) and preserved left ventricular function, as long as the lesion is repairable. He added that over 90% of degenerative lesions were repairable nowadays at his institution. He continued addressing ischemic MR, in which regurgitant volumes and EROs were often deceptively low and still in his way may warrant surgical correction. Exercise echo and myocardial viability should be considered in the decision. Dr.P.Shah from Newport Beach, USA, delineated principles of intraoperative echo and his experience with this technique in mitral valve repair. At his institution, success in attempted valve repair dramatically increased after the institution of a dedicated intraoperative echo service.
Finally, Dr.A.Schwartz, from New York, USA, shared preliminary experience with percutaneous valve repair using the Evalve system, which uses a clip that provides an edge-to-edge repair very similar to the surgical Alfieri technique. The clip is introduced via the femoral vein by transseptal puncture under echo surveillance. Once echo assures that both leaflets have been grasped by the clip and mitral regurgitation is substantially reduced, the clip is released. First results have been published and the safety and efficacy profile is certainly promising.