Clinically relevant perioperative neurological events during transcatheter aortic valve implantation compared to high-risk open aortic valve replacement: results from prospective randomised data.

Introduction: Transcatheter aortic valve implantation (TAVI) has emerged as a minimally invasive surgical option for patients with severe aortic stenosis who are deemed high risk for open aortic valve replacement (AVR). Complication rates for TAVI should be less than or equal to those of traditional AVR in order to justify its use.

Methods: This study was part of a clinical trial studying patients that suffer from aortic stenosis whose surgical mortality risk was deemed to be greater than 15%. The purpose of this study was to determine the perioperative neurological event rates seen in TAVI when compared to traditional open AVR. Patients exhibiting signs of neurological changes were examined by a neurologist and assigned a score on the NIH Stroke Scale (NIHSS). Patients with a NIHSS change of at least 2 and/or neurological changes from baseline within 30 days of operation were identified and compared across both cohorts and within each randomised group. In this study, cohort A refers to patients who were deemed to be of moderate surgical risk of mortality (≥15%), while cohort B refers to patients deemed to be at a high risk of surgical mortality (≥50%).

Results: Incidence of neurological events was compared based on cohort designation and procedure type. The overall perioperative neurological event rate for all patients in the trial was 5.30% (8/151), with no events coming from cohort B (0/36). Eight out of 115 patients (6.96%) in cohort A demonstrated neurological events. Two of 25 patients (8.00%) who underwent open AVR demonstrated neurological changes. Of 50 patients undergoing transfemoral TAVI, five (10%) exhibited neurological changes. Of 40 patients undergoing transapical TAVI, one (2.5%) showed neurological changes. Relevant cross comparisons were made, none of which demonstrated significance.

Discussion: No statistically significant difference was shown between patient groups receiving different interventions, suggesting that TAVI does not pose an increased risk of perioperative neurological changes when compared to open AVR. Diffusion-weighted MRI should be considered to detect clinically silent neurological events for a more correct assessment of risk.