Edge-to-edge percutaneous mitral repair for functional ischaemic and non-ischaemic mitral regurgitation: a systematic review and meta-analysis

Aim: Randomized controlled trials comparing the use of the MitraClip device in addition to guideline directed medical therapy (GDMT) to GDMT alone in patients with secondary mitral regurgitation (MR) have shown conflicting results. However, if these differences could be due to the underlying MR aetiology is still unknown. Therefore, we aimed to evaluate if the effects of percutaneous edge-to-edge repair with MitraClip implantation could differ in patients with ischaemic (I-MR) and non-ischaemic mitral regurgitation (NI-MR).

Methods and results: PubMed, Embase, BioMed Central, and the Cochrane Central Register of Controlled Trials were searched for all studies including patients with secondary MR treated with the MitraClip device. Data were pooled using a random-effects model. Primary endpoint was the composite of all-cause death and heart failure-related hospitalization. Secondary endpoints were the single components of the primary endpoint, New York Heart Association functional Classes III and IV, and mitral valve re-intervention. Seven studies enrolling 2501 patients were included. Patients with I-MR compared with patients with NI-MR had a similar risk of the primary endpoint (odds ratio: 1.17; 95% confidence interval: 0.93 to 1.46; I² : 0%). The risk of all-cause death was increased in patients with I-MR (odds ratio: 1.31; 95% confidence interval: 1.07 to 1.62; I² : 0%), while no differences were observed between the two groups in terms of the other secondary endpoints.

Conclusions: The risk of mortality after MitraClip implantation is lower in patients with NI-MR than in those with I-MR. No absolute differences in the risk of heart failure related hospitalization were observed between groups.