Elevated preprocedural CT-ECV predicts residual LV morphological and functional impairment after TAVI

Background Elevated computed tomography-derived myocardial extracellular volume (CT-ECV) levels reflect the extent of myocardial fibrosis and are associated with adverse cardiac events after transcatheter aortic valve implantation (TAVI). Consequently, incorporating CT-ECV evaluation into TAVI planning may provide valuable prognostic information for risk stratification. This study aims to explore the relationship between CT-ECV and markers of left ventricular decompensation, contributing to a better understanding of its clinical implications in aortic stenosis management. Methods From March 2023 to November 2024, we enrolled patients who underwent TAVI in our institution. CT-ECV was measured as part of routine CT imaging before and one month after TAVI. To explore associations between ECV% and clinical variables, the cohort was divided into tertiles based on the baseline ECV% values: tertile 1 (<26.52%), tertile 2 (26.52% - 30.44%), and tertile 3 (>30.44%). Results Of the 217 TAVI patients, 195 completed one-month follow-up. The mean ECV% at baseline was 28.72 ± 4.25%. At one-month after TAVI, a stepwise increase in BNP levels was found across tertiles (69.4 [43.7 - 115.2] pg/mL in tertile 1, 131.1 [80.6 - 227.3] pg/mL in tertile 2, and 206.5 [94.4 - 284.8] pg/mL in tertile 3, p < 0.0001). Consistently, left ventricular ejection fraction (LVEF) showed a decreasing trend (70.4% [65.9 -73.5] in tertile 1, 69.2% [63.5 - 73.1] in tertile 2, and 62.6% [55.8 - 68.1] in tertile 3, p < 0.0001). In addition, left ventricular mass index (LV mass index) showed an increasing trend (108.7 [93.4 -125.9] g/m2 in tertile 1, 113.5 [91.6 – 134.8] g/m2 in tertile 2, and 125.8 [114.6 – 141.3] g/m2 in tertile 3, p = 0.003). A non-significant impairment in global longitudinal strain (GLS) was found as the ECV% increases (16.5% [14.1 -18.1] in tertile 1, 16.2% [13.4 – 18.7] in tertile 2, and 15.4% [13.2 – 17.6] in tertile 3, p = 0.487). Patients with higher baseline ECV% remained elevated at one-month after TAVI (28.24% [25.19 - 30.98] in tertile 1, 29.25% [25.93 - 33.31] in tertile 2, and 31.36% [27.87 - 34.33] in tertile 3, p = 0.009). Conclusions In patients with severe aortic stenosis undergoing TAVI, elevated preprocedural ECV% was associated with limited LVEF recovery, continuous elevation in BNP levels, and persistent myocardial fibrosis, suggesting the need for intensive pharmacological management following TAVI.