ABSTRACT NUMBER: ESOC2026A784 EARLY CEREBRAL MICRO-EMBOLIZATION AFTER CARDIAC VALVE SURGERY: A TRANSCRANIAL DOPPLER STUDY USING A SOLID–GASEOUS EMBOLUS CLASSIFICATION ALGORITHM

Abstract Background and aims Micro-embolic signals (MES) can be detected by transcranial Doppler (TCD), but data on their occurrence immediately after cardiac valve surgery remain limited. This study evaluated the incidence, characteristics, and clinical relevance of MES during the early postoperative period. Methods A number of 93 patients (mean age 67 years; 83.9% male) undergoing aortic (AVS, n=70) or mitral valve surgery (MVS, n=23) between 2019 and 2022 were monitored using TCD during the first four postoperative hours. MES were identified and classified using a peer-validated solid–gaseous–artefact algorithm. Associations between MES burden, embolus type, valve characteristics, and early postoperative outcomes were analyzed. Results Baseline preoperative recordings in 20 patients showed no MES except for one presumed solid embolus. Postoperatively, MES were detected in 85% of patients, with counts ranging from 1 to 88 per hour. Sixteen percent of patients exhibited a high MES burden (>20/hour), predominantly after AVS. Overall, 43% of MES were classified as solid and 57% as gaseous. MES burden was significantly higher after AVS than MVS (48.5 vs 3.2 MES/hour; p<0.005). Mechanical AVS was associated with a higher proportion of gaseous emboli than biological valves (gaseous/solid ratio 10.1 vs 1.1; p<0.05). Higher solid MES counts correlated with increasing age. Adverse events occurred in 9.7% of patients. Conclusions The application of a validated solid–gaseous embolus classification algorithm enabled structured interpretation of a large and complex Doppler dataset, revealing clinically relevant differences in embolus burden and composition related to valve type and patient age. The clinical relevance needs further exploration. Conflict of interest Keunen ahs a disclosure: he is owner of Keunen Medical a developer of TCD software algorithms. Daal, Romers, Keyhan-Falsafi, Hoohenkerk, Mariani, Teeuws, van Kampen have nothing to disclose