ABSTRACT NUMBER: ESOC2026A621 INTRA-CARDIAC THROMBUS IDENTIFIED IN A HIGHER PROPORTION OF CARDIAC CT STUDIES WITH USE OF ELECTROCARDIOGRAM-GATING

Abstract Background and aims Cardiac computed tomography (CT) is increasingly used as part of acute stroke brain imaging, but heterogeneity exists with respect to imaging protocols. We compared the proportion of patients diagnosed with intra-cardiac thrombus on ECG-gated and non-ECG-gated cardiac CT. Methods An individual patient data meta-analysis was undertaken of data from an international observational registry (The Netherlands, New Zealand and Australia), which included patients who underwent cardiac CT as part of acute stroke imaging. Data were obtained from between May 2018 and June 2024. The primary outcome was the proportion of cases with thrombus identified on cardiac CT. Results There were 3906 patients included in the analysis: 1457 (37.3%) underwent ECG-gated cardiac CT and 2449 (62.7%) underwent non-ECG-gated cardiac CT. Patients who underwent ECG-gating were younger (median age 72 versus 74, P < 0.001) and had a lower baseline prevalence of AF (17.4% versus 26.7%, P < 0.001), chronic heart failure (5.6% versus 12.6%, P < 0.001), hypertension (50.0% versus 61.7%, P < 0.001), dyslipidaemia (16.4% versus 34.2%, P < 0.001) and ischaemic heart disease (18.3% versus 23.1%, P < 0.001). The pooled positivity rate for thrombus was higher in the ECG-gated group (7.8% versus 5.5% respectively, odds ratio 1.44, 95% CI 1.11—1.87, P = 0.006). After adjustment for confounders, the association remained significant (adjusted OR 2.18, 95% CI: 1.60-2.96, P < 0.001). Conclusions ECG-gated cardiac CT identified thrombus in a higher proportion of patients compared to those who underwent cardiac CT without ECG-gating. Conflict of interest Daniel S Green: This research was supported by the Australian Government Research Training Program Scholarship. Shan Sui Nio: Funding support from the Dutch Heart Foundation and travel grants (Cultuurfonds, Remmert Adriaan Laan Fonds, CONTRAST, Dr Jan Meerwaldt Stichting). Luis Mena-Romo: Nothing to disclose. Alexander Berry-Noronha: Nothing to disclose. Beng Lim Alvin Chew: Nothing to disclose. Leon Rinkel: Leon is supported by the Dutch Heart Foundation (Junior Clinical Scientist Grant). Teddy Y Wu: Nothing to disclose. Jonathan M Coutinho: JMC reports research support from Bayer and AstraZeneca (all paid to his employer) and is co-founder and shareholder of TrianecT. Mark W Parsons: Nothing to disclose. Carlos Garcia-Esperon: Funding support from the NSW Health Cardiovascular Researcher Grants (2024).