MitraClip in CRT Non-responders with Severe Mitral Regurgitation

Background: Severe mitral regurgitation (MR) ≥ 3+ and left ventricular dyssynchrony in heart failure patients are markers of CRT non response. The MitraClip (MC) implantation is a therapy for MR ≥ 3+ in patients with high surgical risk of mitral valve reconstruction.

Methods And Results: We investigated 42 patients with CRT and MR ≥ 3+ who received an MC device at our center. One and two year mortality rates were compared with the predicted mortality by Seattle Heart Failure Model (SHFM) and meta-analysis global group in chronic heart failure (MAGGIC), using the baseline characteristics of patients at the time of MC implantation. The median time interval between CRT and MC implantation was 20.1 (4.5-43.3) months. In 19 patients we observed a functional regurgitation with normal leaflets and in 23 patients a degenerative mechanism for mitral regurgitation. There was no change in mean QRS duration by biventricular pacing or MC implantation. The use of MC led to significant reductions in: median N-terminal pro-brain natriuretic peptide (NT-proBNP) level (pg/ml) from 3923 to 2636 (p = 0.02), tricuspid regurgitation pressure gradient (TRPG) from 43 to 35 mmHg (p = 0.019) and in left ventricular end-diastolic volume (LVEDV) by MC (p = 0.008). At the 2 year follow-up interval the all-cause mortality was 25%.

Conclusion: MC implantation leads to an improvement of NT-proBNP level, TRPG and LVEDV in both functional and degenerative MR but does not influence QRS duration. Two year all-cause mortality was 25% and did not differ significantly from that predicted by SHFM and MAGGIC.