Diagnostic Accuracy of an Algorithm for Discriminating Presumed Solid and Gaseous Microembolic Signals During Transcranial Doppler Examinations.

OBJECTIVE: The aim of the work described here was to assess the diagnostic accuracy of a new algorithm (SGA-a) for time-domain analysis of transcranial Doppler audio signals to discriminate presumed solid and gaseous microembolic signals and artifacts (SGAs). METHODS: SGA-a was validated by human experts in an artifact cohort of 20 patients subjected to a 1-h transcranial Doppler exam before cardiac surgery (cohort 1). Emboli were validated in a cohort of 10 patients after aortic valve replacement in a 4-h monitoring period (cohort 2). The SGA misclassification rate was estimated by testing SGA-a on artifact-free test files of solid and gaseous emboli. RESULTS: In cohort 1 (n = 24,429), artifacts were classified with an accuracy of 94.5%. In cohort 2 (n = 12,328), the accuracy in discriminating solid/gaseous emboli from artifacts was 85.6%. The 95% limits of agreement for, respectively, the numbers of presumed solids and gaseous emboli, artifacts and microembolic signals of undetermined origin were [-10, 10], [-14, 7] and [-9, 16], and the intra-class correction coefficients were 0.99, 0.99 and 0.99, respectively. The rate of misclassification of solid test files was 2%, and the rate of misclassification of gaseous test files was 12%. CONCLUSION: SGA-a can detect presumed solid and gaseous microembolic signals and differentiate them from artifacts. SGA-a could be of value when both solid and gaseous emboli may jeopardize brain function such as seen during cardiac valve and/or aortic arch replacement procedures.

Clinical Outcome of Transcatheter Aortic Valve Replacement With TriGUARD 3™ Cerebral Embolic Protection Device.

OBJECTIVE: Periprocedural stroke during transcatheter aortic valve replacement (TAVR) is a highly feared adverse event. The TriGUARD 3 cerebral embolic protection device (CEPD) may have the potential benefit of reduction of embolic events, but it still remains unclear whether it reduces the incidence of periprocedural stroke or transient ischemic attack (TIA). We aimed to investigate whether the latest TriGUARD 3 CEPD reduces the incidence of clinically overt stroke within 72 h or at discharge after TAVR. METHODS: In this prospective single-center study 117 patients (mean age 80.3 years, 53.8 % male) were included from July 2020 to December 2021. RESULTS: The primary efficacy endpoint of this study, periprocedural clinically overt stroke or TIA, within 72 h or at discharge after TAVR with the TriGUARD 3 CEPD occurred in 1/117 pts (0.8 %). Secondary endpoints (device related issues such as life-threatening or disabling bleeding, acute kidney injury, major vascular complications) were reported in 4/117 pts (3.4 %). CONCLUSIONS: This study suggests that the use of the latest TriGUARD 3™ CEPD in transfemoral TAVR seems to be associated with a low rate of clinically overt stroke and a low rate of device related adverse events, reflecting "real world" TAVR practice. However these results should be hypothesis generating and confirmed in a large RCT.