Patterns of solid particle embolization during transcatheter aortic valve implantation and correlation with aortic valve calcification.

Abstract

To evaluate solid embolization during transcatheter aortic valve implantation (TAVI) and correlate this with aortic valve calcification. There is a known stroke risk with TAVI, thought partly to be due to dislodgement of native aortic valve particles during implantation. However, to date there is little evidence that aortic valve calcification actually impacts embolic risk. Transcranial Doppler (TCD) was performed on consecutive suitable patients undergoing TAVI, using hardware and software enabling differentiation between solid and gaseous emboli. Data was analyzed by time points during the TAVI procedure. These results were correlated with aortic valve calcification. TCD was successfully performed on 63 patients. The median number of solid emboli was 76.0. The most common time point for solid embolization was during valve positioning. Forty-five of these patients had an appropriate CT scan which could be analyzed for an Agatston calcium score. The mean scores in the aortic valve and aortic root were 3382.4 and 754.9. There were significant correlations between the total number of solid emboli and valve calcium score (P = 0.033) and solid emboli during valve positioning and valve calcium score (P = 0.035). There was no relationship between gaseous emboli and valve calcium score. TAVI is associated with significant solid particle embolization, with the most common time point being during valve positioning. Solid embolization correlates with aortic valve calcium score, suggesting that valve calcification is a factor in embolic risk. This should be taken into consideration along with other clinical factors when assessing embolic risk.