Objective:To assess the predictive value for the risk of cardiogenic stroke (CS) in patients with paroxysmal atrial fibrillation (PAF) using quantification of left atrial appendage early blood stasis (LAA-BS) signs derived from left atrium-pulmonary vein CT examination.Methods:A retrospective analysis of 187 patients with PAF, who were confirmed to have LAA-BS by left atrium-pulmonary vein CT examinations, was conducted at Second Affiliated Hospital of Nantong University from January 2019 to December 2021. The ratio of LAA-BS CT values to ascending aorta (AA) CT values (HU BS/HU AA) and the ratio of LAA-BS volume to LAA volume (V BS/V LAA) were measured at the peak time of AA enhancement, which were used as characteristic quantitative indicators of LAA-BS. Using the median values of HU BS/HU AA and V BS/V LAA as cut-off points for grouping, the differences between the high-ratio and low-ratio groups were compared in terms of general information, clinical characteristics, and imaging characteristics. All enrolled patients were followed up with the primary outcome event of CS occurrence. The differences in the proportion of CS occurrence between the high-ratio and low-ratio groups were compared. The risk stratification analysis of the occurrence of CS in PAF patients was performed using Kaplan-Meier curves. Additionally, the predictive value of HU BS/HU AA, V BS/V LAA and other imaging indices for the risk of CS occurrence was assessed using Cox proportional risk regression models. Results:The incidence of hypertension and the proportion of patients with atrial fibrillation-stroke risk score (CHA 2DS 2-VASc)≥3 in the high V BS/V LAA group were higher than that in the low V BS/V LAA group, and the difference was statistically significant ( P=0.041, P=0.011). The left atrial volume (LAV) in patients in the low HU BS/HU AA group was greater than in the high HU BS/HU AA group, and the difference was statistically significant ( P=0.040). Kaplan-Meier analysis showed a higher incidence of CS in the low HU BS/HU AA group than in the high HU BS/HU AA group ( P=0.012). Similarly, the high V BS/V LAA group had a higher incidence of CS compared with the low V BS/V LAA group ( P=0.019). Subgroup analysis revealed a significantly higher incidence of CS in the subgroup with low HU BS/HU AA and high V BS/V LAA compared to other subgroups (all P<0.05). The Cox proportional hazards regression model, adjusting for confounding factors, identified low HU BS/HU AA and high V BS/V LAA as independent risk factors for CS occurrence in PAF patients ( P=0.005 and P=0.029). Conclusion:The HU BS/HU AA and V BS/V LAA quantified using left atrium-pulmonary vein CT imaging are predictive factors for CS occurrence in patients with PAF. These ratios synergistically contribute to the risk assessment of CS.

Objective:To assess the predictive value for the risk of cardiogenic stroke (CS) in patients with paroxysmal atrial fibrillation (PAF) using quantification of left atrial appendage early blood stasis (LAA-BS) signs derived from left atrium-pulmonary vein CT examination.Methods:A retrospective analysis of 187 patients with PAF, who were confirmed to have LAA-BS by left atrium-pulmonary vein CT examinations, was conducted at Second Affiliated Hospital of Nantong University from January 2019 to December 2021. The ratio of LAA-BS CT values to ascending aorta (AA) CT values (HU BS/HU AA) and the ratio of LAA-BS volume to LAA volume (V BS/V LAA) were measured at the peak time of AA enhancement, which were used as characteristic quantitative indicators of LAA-BS. Using the median values of HU BS/HU AA and V BS/V LAA as cut-off points for grouping, the differences between the high-ratio and low-ratio groups were compared in terms of general information, clinical characteristics, and imaging characteristics. All enrolled patients were followed up with the primary outcome event of CS occurrence. The differences in the proportion of CS occurrence between the high-ratio and low-ratio groups were compared. The risk stratification analysis of the occurrence of CS in PAF patients was performed using Kaplan-Meier curves. Additionally, the predictive value of HU BS/HU AA, V BS/V LAA and other imaging indices for the risk of CS occurrence was assessed using Cox proportional risk regression models. Results:The incidence of hypertension and the proportion of patients with atrial fibrillation-stroke risk score (CHA 2DS 2-VASc)≥3 in the high V BS/V LAA group were higher than that in the low V BS/V LAA group, and the difference was statistically significant ( P=0.041, P=0.011). The left atrial volume (LAV) in patients in the low HU BS/HU AA group was greater than in the high HU BS/HU AA group, and the difference was statistically significant ( P=0.040). Kaplan-Meier analysis showed a higher incidence of CS in the low HU BS/HU AA group than in the high HU BS/HU AA group ( P=0.012). Similarly, the high V BS/V LAA group had a higher incidence of CS compared with the low V BS/V LAA group ( P=0.019). Subgroup analysis revealed a significantly higher incidence of CS in the subgroup with low HU BS/HU AA and high V BS/V LAA compared to other subgroups (all P<0.05). The Cox proportional hazards regression model, adjusting for confounding factors, identified low HU BS/HU AA and high V BS/V LAA as independent risk factors for CS occurrence in PAF patients ( P=0.005 and P=0.029). Conclusion:The HU BS/HU AA and V BS/V LAA quantified using left atrium-pulmonary vein CT imaging are predictive factors for CS occurrence in patients with PAF. These ratios synergistically contribute to the risk assessment of CS.

Objective:To investigate the predictive value for major adverse cardiovascular events (MACE) occurring within 1 year in patients with old myocardial infarction(OMI) using characteristics of myocardial scar derive from dual-energy CT (DECT) post-processing technique.Methods:OMI patients who received coronary CT angiography following dual-energy CT with late iodine enhancement (LIE-DECT) in the Second Affiliated Hospital of Nantong University from November 2019 to October 2022 were continuously included, and the images of all enrolled patients were reconstructed using 40 keV monoenergetic plus (Mono+) map, LIE (representing myocardial scar) was quantified on left ventricular short-axis images, including the LIE segments, the LIE score, and the LIE degree. All enrolled patients were followed up for MACE, defined as hospitalization for heart failure, malignant arrhythmia, and cardiac death. Regression analysis was used to investigate the relationship between the quantified value of myocardial scar and the occurrence of MACE, and receiver operating characteristic curve (ROC) was used to evaluate the efficacy of quantified value of myocardial scar in predicting MACE. The area under the curve (AUC) was compared using the DeLong test.Results:Finally, 231 patients with OMI were included, and MACE occurred in 37 cases (16.0%) within 1 year after LIE-DECT examination. The LIE segments 5 (4, 7), the LIE score 27 (13, 49) and the LIE degree 9.4%(7.5%, 15.5%) in the MACE group were higher than those in the non-MACE group 3 (2, 5), 9 (6, 15) and 6.7%(6.3%, 7.9%) (all P<0.001). Multivariable logistic regression analysis showed that after adjusting for confounders, the LIE segments ( OR=2.118, P<0.001), the LIE score ( OR=3.168, P<0.001), and the LIE degree ( OR=3.092, P<0.001) remained risk factors for the development of MACE. On ROC analysis, AUC of LIE segments, LIE score and LIE degree were 0.715, 0.822 and 0.806 (all P<0.001), with sensitivities of 81.1%, 86.5%, and 91.9%, and specificities of 53.6%, 69.6%, and 60.8%, respectively. DeLong′s test showed that the predictive efficacy of LIE score and LIE degree was higher than that of LIE segments ( Z=2.63, P=0.008; Z=1.96, P=0.049), and there were no significant differences in the predictive efficacy of LIE score and LIE degree ( Z=0.60, P=0.551). Conclusion:The LIE segments, the LIE score and the LIE degree detected by LIE-DECT 40 keV Mono+maps are risk factors for the occurrence of MACE in patients with OMI and have good efficacy in predicting the occurrence of MACE, which can be used as important indicators for assessing the clinical prognosis of OMI.