Contrast Fractional Flow Reserve (cFFR) and Computed Tomography Fractional Flow Reserve (CT-FFR) Guidance for Percutaneous Coronary Intervention (PCI)

In this review, we summarize both contrast fractional flow reserve (cFFR) and computed tomography fractional flow reserve (CT-FFR) as novel modalities to evaluate the hemodynamic significance of coronary artery stenoses and to guide percutaneous coronary intervention (PCI). Implementation of cFFR can reduce the time, cost, effort, and patient discomfort associated with traditional adenosine FFR. Clinical outcomes following cFFR-guided revascularization are currently under investigation. Emerging data on the use of CT-FFR in patients with acute coronary syndromes may increase the use of this technology in acute settings, while virtual stenting applications to model the hemodynamic results of stent placement may help optimize PCI planning. Using contrast media already available for traditional angiography, cFFR yields results that are highly reproducible and correlate more closely with traditional adenosine FFR than the distal/aortic pressure ratio (Pd/Pa) or the instantaneous wave-free ratio (iFR). Based upon computational fluid dynamics, CT-FFR provides a non-invasive estimate of the traditional adenosine FFR and predicts ischemia more accurately than nuclear imaging. Therefore, CT-FFR has begun to take on a gatekeeper role to minimize unnecessary invasive angiography.