Left ventricular ejection fraction by computed tomography in severe aortic stenosis patients - real world experience

Introduction The left ventricular ejection fraction (LVEF) is pivotal for predicting cardiac outcomes and treatment decisions, with multiple imaging methods available for its assessment. While cardiac computed tomography (CCT) serves as a standard test to evaluate the aortic valve structure prior to transcatheter aortic valve implantation (TAVI), it typically focuses on assessing the aortic valve rather than routinely providing quantitative information about LVEF despite its capability to offer insights into other cardiac structures. Purpose The aim of this study is to assess the correlation and agreement between LVEF measured by two-dimensional transthoracic echocardiography (TTE) and CCT in severe aortic stenosis patients. Methods Single-center, retrospective study. Patients undergoing CCT preceding TAVI for severe aortic stenosis from June until December 2023 were selected. Patients without measurements for both TTE and CCT LVEF were excluded from the analysis. The paired-sample T-test and Pearson's coefficient of correlation (r) were calculated, and the Bland-Altman plot was inspected to assess the between-agreement measurements of the two modalities, using SPSS 28.0.1.1 software. Results Of the 113 patients with severe aortic stenosis identified, only 42 (37.2%) had measurements of both TTE and CCT LVEF and were enrolled in the analysis. The mean age of the population was 82.3 (±6.8) years, 64.3% female. Cardiovascular risk factors were significantly prevalent: 90.0% had arterial hypertension, 75.0% had dyslipidemia, and 47.5% had diabetes. The prevalence of coronary artery disease was considerable (28.2%). Based on the LVEF-TTE assessment, 21.4% of patients had LVEF inferior to 50%. Despite a statistically significant difference between TTE and CCT LVEF means (55.5±10.6% vs. 61.9±15.4%, p<0.001), a positive moderate correlation was observed between the measurements (r=0.606; p<0.001). In the subgroup analysis, the correlation was stronger in patients with LVEF lower than 50% (r=0.759, p=0.018) when compared with the higher LVEF group (r=0.427; p=0.013). Analyzing the Bland-Altman plot of LVEF from the comparison between the two imaging modalities, CCT showed an overall tendency to overestimate LVEF (mean difference=-6.43±10.56%), particularly with LVEF increasing. Conclusion Despite a moderate correlation, CCT gives considerably different LVEF measurements than TTE in severe aortic stenosis patients undergoing CCT prior to TAVI. CCT showed a tendency to systematically overestimate LVEF, highlighting the importance of careful interpretation when comparing these imaging findings.