ISSN 2996-8215
International Journal of Cardiology | Vol. 6, No. 7, July 2015 | pp. 49–56
DOI: 10.46882/2015/IJC/000076
Original Research Article
Diagnostic Performance of Fractional Flow Reserve derived from Computed Tomography in Patients with Severe Coronary Calcification
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:
Computed tomography coronary angiography (CTCA) exhibits lower diagnostic specificity in patients with heavy coronary calcification due to blooming artifacts that falsely accentuate luminal narrowing. Fractional flow reserve derived from standard CTCA datasets (FFR-CT) applies computational fluid dynamics to evaluate lesion-specific ischemia non-invasively. This study evaluated the diagnostic performance of FFR-CT for identifying ischemia-producing lesions specifically in patients with high baseline coronary artery calcium (CAC) scores. We prospectively enrolled 115 symptomatic patients with intermediate anatomical coronary stenoses and an Agatston CAC score greater than 400 who were scheduled for diagnostic invasive angiography and fractional flow reserve (FFR). FFR-CT was processed off-line using specialized fluid software. Ischemia was defined as an invasive FFR 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 a 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 narrowing criteria alone (0.88 vs. 0.65, p < 0.001). Fractional flow reserve computed from CTCA datasets maintains high diagnostic accuracy and strong negative predictive value for identifying hemodynamically significant lesions even in the presence of severe calcification, optimizing triage and avoiding unnecessary invasive procedures.
Keywords: Computed tomography coronary angiography, Fractional flow reserve, Coronary calcification, Computational fluid dynamics, Myocardial ischemia, Diagnostic accuracy
Received: April 02, 2015; Revised: May 15, 2015; Accepted: June 08, 2015; Published: July 24, 2015