A study has indicated that percutaneous edge-to-edge mitral valve repair with the MitraClip (Abbott Vascular) can be performed safely and effectively, in experienced centres, in both patients with central degenerative mitral regurgitation and those with non-central degenerative mitral regurgitation
Writing in the Journal of the American College of Cardiology, study authors Rodrigo Estévez-Loureiro (National Institute Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK) and others comment that reports have indicated that the MitraClip can be used successfully to treat mitral regurgitation in patients with more complex pathologies than those in the EVEREST II trial, which showed the MitraClip device was less effective but safer than surgery in patients with central mitral regurgitation. They add: “However, little is known regarding applicability of the procedure in non-central degenerative mitral regurgitation. The aim of this study was to compare acute and mid-term safety and efficacy of MitraClip treatment of patients with central vs. non-central degenerative mitral regurgitation.”
The authors performed a retrospective analysis of patients who had been implanted with the MitraClip between 2009 and 2012 (at one of three centres: Royal Brompton Hospital, UK; Karolinska University Hospital, Sweden; and Rigshospitalet, Denmark). The inclusions criteria for the analysis were severe degenerative mitral regurgitation, a predicted benefit of mitral regurgitation, and high surgical risk.
Of the 79 patients in the study, 49 had central degenerative mitral regurgitation and 30 had non-central degenerative regurgitation. All patients underwent transthoracic and transoesophageal echocardiography (TEE) prior to the intervention and all were examined with 2D and 3D-TEE during the procedure. Estévez-Loureiro et al report that there no significant differences in the rate of procedure success or the rate of procedure complications between groups. However although there were also no significant differences in procedure time or the number of clips used, the procedure time was slightly longer and numerically more patients received more than one clip in the non-central group compared with the central group.
They add: “We observed a reduction in mitral regurgitation severity in all patients, with most of the patients having mitral regurgitation ≤2. There were no differences in the extent of reduction of mitral regurgitation between the central and non-central group. The reduction in mitral regurgitation was sustained in both groups at six months, with non-significant differences in the proportion of patients with mitral regurgitation >2.”
According to the authors, their results show, for the first time, the feasibility of treating non-central degenerative mitral regurgitation with the MitraClip. They note: “These findings challenge the concept that non-central positioning of a MitraClip is associated with worse clinical outcomes because of interference with the subvalvular apparatus. There was no prolonged clip entanglement in the non-central group. It suggests that the indication for MitraClip implantation may be expanded to non-central degenerative mitral regurgitation.”
However, Estévez-Loureiro et al say that “certain practical issues” need to be considered before the indication is expanded, including that intraprocedural 3D-TEE was “felt essential” for non-central patients undergoing MitraClip implantation, that there were procedural changes in the non-central group (such as guide catheter positioning), and that the rate of MitraClip implantation in patients with non-central degenerative mitral regurgitation increased over time (suggesting that there is learning curve).
“MitraClip treatment of non-central degenerative mitral regurgitation is safe and associated with similar acute and mid-term outcome as the treatment of central mitral regurgitation,” the authors conclude.