Accuracy of on-site CT-uFR analyses for evaluation of intermediate coronary stenoses in patients undergoing TAVI

Abstract Background Recent studies showed the clinical benefit of functional evaluation of coronary stenoses among patients undergoing transcatheter valve implantation (TAVI). Novel solutions enabled the non-invasive assessment directly from coronary computed tomography angiography (CCTA); however, current approaches are limited. A recently developed software enables on-site evaluation of computed tomography-derived Murray law-based quantitative flow ratio (CT-μFR), yet its diagnostic accuracy has not been validated in patients undergoing TAVI. This study aimed to assess the diagnostic utility of CT-μFR in patients undergoing TAVI. Methods This multicenter, cross-sectional study included patients who underwent CCTA and fractional flow reserve (FFR) assessment prior to TAVI. CT-μFR and plaque characteristics were evaluated using dedicated software (CtaPlus, Pulse Medical Technology) by an analyst blinded to the initial FFR results. The two coprimary endpoints were the accuracies of CT-μFR in identifying physiologically significant coronary artery stenosis, defined as FFR values ≤ 0.80 and ≤ 0.83, respectively. Results This study included 50 vessels from 42 patients (mean age of 78.9±8.0). Median FFR was 0.87 (IQR: 0.82–0.90) and median CT-μFR was 0.89 (IQR: 0.82–0.92)(p = 0.45); a strong correlation was observed between the two modalities (r=0.832, p<0.001). At the lesion level, using an FFR threshold of 0.80, CT-μFR demonstrated 92% diagnostic agreement, with 82% sensitivity and 95% specificity. Using an FFR threshold of 0.83, the agreement remained 92%, with sensitivity of 87% and specificity of 94%. Conclusion CT-μFR demonstrated strong agreement with invasive FFR among patients undergoing TAVI. These results underscore the need for prospective studies to validate the clinical applicability.Figure 1For image description, please refer to the figure legend and surrounding text.