ISSN 2996-8215
International Journal of Cardiology | Vol. 14, No. 7, July 2023 | pp. 49–56
DOI: 10.46882/2023/IJC/000171
Original Research Article
Diagnostic Performance of Non-Invasive FFR-CT for Identifying Ischemia-Producing Lesions in Severely Calcified Coronary Arteries
Arjun Patel¹, Rohan Mehta¹, Vikram Singh²
¹Department of Cardiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
²Division of Cardiovascular Radiology, All India Institute of Medical Sciences, New Delhi, India
Abstract:
Severe coronary artery calcification introduces severe blooming artifacts during computed tomography coronary angiography (CTCA), which limits structural specificity and results in false-positive findings. Fractional flow reserve derived from standard CTCA datasets (FFR-CT) utilizes computational fluid dynamics to evaluate lesion-specific ischemia non-invasively. This multi-center prospective study evaluated the diagnostic performance of FFR-CT for identifying hemodynamically significant lesions in patients with heavy coronary calcification. We enrolled 115 symptomatic patients with an intermediate anatomical coronary stenosis (30% to 70%) and a baseline Agatston coronary artery calcium (CAC) score greater than 400 who were scheduled for invasive coronary angiography and fractional flow reserve (FFR). FFR-CT was processed off-line using specialized fluid dynamics software, with ischemia defined as an FFR-CT less than or equal to 0.80. On a vessel-based analysis (142 vessels total), invasive FFR confirmed lesion-specific ischemia in 45 vessels (31.7%). Non-invasive FFR-CT demonstrated a diagnostic sensitivity of 86.7% (95% CI: 73.2%–94.9%), a specificity of 81.4% (95% CI: 72.3%–88.6%), and an overall negative predictive value (NPV) of 92.9% (95% CI: 85.3%–97.4%). The area under the receiver operating characteristic curve for FFR-CT was significantly superior to standard anatomical CTCA luminal assessment alone (0.88 vs. 0.65, p < 0.001). Fractional flow reserve computed non-invasively from CTCA datasets maintains high diagnostic precision and high negative predictive value even in severely calcified coronary arteries, reducing unnecessary diagnostic invasive procedures.
Keywords: Computed tomography coronary angiography, Fractional flow reserve, Coronary calcification, Computational fluid dynamics, Myocardial ischemia, Diagnostic accuracy
Received: April 02, 2023; Revised: May 15, 2023; Accepted: June 08, 2023; Published: July 24, 2023