Cerebral Embolization During Transcatheter Aortic Valve Implantation: A Transcranial Doppler Study

Transcatheter aortic valve implantation (TAVI) is associated with a higher risk of neurological events for both the transfemoral and transapical approach than surgical valve replacement. Cerebral magnetic resonance imaging has revealed more new, albeit clinically silent lesions from procedural embolization, yet the main source and predominant procedural step of emboli remain unclear. Eighty-three patients underwent transfemoral (Medtronic CoreValve [MCV(TF)], n=32; Edwards Sapien [ES(TF)], n=26) and transapical (ES(TA): n=25) TAVI. Serial transcranial Doppler examinations before, during, and 3 months after TAVI were used to identify high-intensity transient signals (HITS) as a surrogate for microembolization. Procedural HITS were detected in all patients, predominantly during manipulation of the calcified aortic valve while stent valves were being positioned and implanted. The balloon-expandable ES prosthesis caused significantly more HITS (mean [95% CI]) during positioning (ES(TF), 259.9 [184.8-334.9]; ES(TA), 206.1[162.5-249.7]; MCV(TF), 78.5 [25.3-131.6]; P