Incidence, characteristics and functional implications of cerebral embolic lesions after the MitraClip procedure

Aims: This study aimed to assess the incidence and impact of cerebral embolic events after the MitraClip procedure. Methods and results: Twenty-seven high-risk patients (logistic EuroSCORE I 25±15%) underwent the MitraClip procedure and cerebral diffusion-weighted magnetic resonance imaging (MRI) in median two days before and three days after the procedure. On the same day, neurocognitive function was assessed using the Montreal Cognitive Assessment (MoCA) questionnaire and thorough clinical examination. Comparison of pre- and post-interventional MRI showed that 23 of 27 patients (85.7%) had newly acquired microembolic lesions with in median three (interquartile range 1-9) new lesions per patient. Of these, three patients (11.1%) had lesions with diameter >5 mm. Patients with >3 new cerebral embolic lesions (n=13, 48%) had a lower post-interventional MoCA score in comparison to patients with ≤3 embolic lesions (23.6±3.6 vs. 20.3±4.5; p=0.046) in univariate analysis. Multivariate stepwise regression analysis identified device time as an independent predictor of the number of post-procedural new lesions (p=0.003) and, for reduced post-interventional MoCA score, a low MoCA score at baseline (p<0.001). Conclusions: The MitraClip procedure results in new ischaemic cerebral lesions in the vast majority of patients. Preliminary data suggest that these lesions are clinically without significant impact on global cognitive function.