Cerebral embolic exposure during transfemoral and transapical transcatheter aortic valve replacement

To characterize the cerebral embolic exposure during transfemoral (TF) and transapical (TA) TAVR.

To detect cerebral embolic events during TAVR, intraoperative neuromonitoring using transcranial Doppler (TCD) was utilized in 28 patients (Edwards SAPIEN valve TF n = 18, TA n = 10). High intensity transient signals (HITS) reflective of embolic events were recorded.

The mean age was 83.4 ± 7.4 years. The Society of Thoracic Surgeons predicted risk of mortality score was 11.7 ± 2.9. The total number of HITS during TAVR was not significantly different between the TF and the TA groups, respectively (375 ± 301, 440 ± 283, p = 0.58). The highest number of HITS occurred during wire manipulation in the arch and valve insertion (TF, 80 ± 110, 107 ± 81; TA, 120 ± 80, 92 ± 80). In the TF group only, severe arch calcification was associated with significantly higher number of HITS both in total number of HITS (Grade I/II, 278 ± 71; Grade III/IV, 568 ± 479, p = 0.05) and during wire manipulation in the arch and valve insertion (Grade I/II, 140 ± 46, Grade III/IV 294 ± 239, p = 0.04).

Highest cerebral embolic exposure occurred during wire manipulation in the arch and valve insertion in both the TF and TA groups. Arch calcification appears to be associated with increased embolic risk, specifically in the TF approach. Understanding of the mechanism of cerebral embolism is needed for future strategies of cerebral protection during TAVR.