Usefulness of FFR-CT to exclude haemodynamically significant lesions in high-risk NSTE-ACS
David Meier, Daniele Andreini, Bernard Cosyns, Ioannis Skalidis, Tatyana Storozhenko, Thabo Mahendiran, Emilio Assanelli, Jeroen Sonck, Bram Roosens, David C. Rotzinger, Salah D. Qanadli, Γεώργιος Τζίμας, Olivier Müller, Bernard De Bruyne, Carlos Collet, Stéphane Fournier
Abstract
BACKGROUND: Coronary computed tomography angiography (CCTA) and fractional flow reserve (FFR) derived from CCTA (FFR-CT) may provide a means of reducing unnecessary invasive coronary angiography (ICA) in patients with suspected non-ST-elevation acute coronary syndromes (NSTE-ACS). AIMS: The aim of this study was to evaluate the capacity of FFR-CT and CCTA to rule out significant lesions in high-risk NSTE-ACS patients, using ICA with invasive FFR as the gold standard. METHODS: High-risk NSTE-ACS patients admitted to 4 European centres were enrolled in this single-arm, prospective core lab-adjudicated study. Patients underwent CCTA with FFR-CT analysis, followed by ICA with invasive FFR. RESULTS: Out of the 250 initially planned NSTE-ACS patients, 168 were included, of whom 151 (92%) had sufficient CCTA image quality to undergo CCTA and FFR-CT analysis. The median high-sensitivity troponin T level at 1 hour post-hospitalisation was 5.3 (interquartile range: 1.8-18.6) times the upper reference limit. At the patient level, the diagnostic performance of FFR-CT was numerically higher as compared to CCTA though not statistically significant (sensitivity: 94% vs 93%, specificity: 63% vs 54%, positive predictive value: 83% vs 79%, negative predictive value: 85% vs 80% and accuracy: 83% vs 79%; p=0.58), suggesting an enhanced capability to avoid unnecessary ICA. At the lesion level, the ability of FFR-CT to detect significant lesions was significantly better than that of CCTA (receiver operating characteristic curves: 0.84 vs 0.65 respectively; p<0.01). CONCLUSIONS: In patients with high-risk NSTE-ACS, FFR-CT offers better diagnostic accuracy - though not statistically significant - and a higher ability to rule out haemodynamically significant stenoses as compared to CCTA. This indicates that FFR-CT can reduce unnecessary invasive procedures by more accurately identifying patients requiring further intervention.