Non-invasive procedural planning using computed tomography-derived fractional flow reserve

Objectives This study aimed to investigate the performance of computed tomography derived fractional flow reserve based interactive planner (FFR(CT)planner) to predict the physiological benefits of percutaneous coronary intervention (PCI) as defined by invasive post-PCI FFR. Background Advances in FFR(CT)technology have enabled the simulation of hyperemic pressure changes after virtual removal of stenoses. Methods In 56 patients (63 vessels) invasive FFR measurements before and after PCI were obtained and FFR(CT)was calculated using pre-PCI coronary CT angiography. Subsequently, FFR(CT)and invasive coronary angiography models were aligned allowing virtual removal of coronary stenoses on pre-PCI FFR(CT)models in the same locations as PCI was performed. Relationships between invasive FFR and FFRCT, between post-PCI FFR and FFR(CT)planner, and between delta FFR and delta FFR(CT)were evaluated. Results Pre PCI, invasive FFR was 0.65 +/- 0.12 and FFR(CT)was 0.64 +/- 0.13 (p= .34) with a mean difference of 0.015 (95% CI: -0.23-0.26). Post-PCI invasive FFR was 0.89 +/- 0.07 and FFR(CT)planner was 0.85 +/- 0.07 (p< .001) with a mean difference of 0.040 (95% CI: -0.10-0.18). Delta invasive FFR and delta FFR(CT)were 0.23 +/- 0.12 and 0.21 +/- 0.12 (p= .09) with a mean difference of 0.025 (95% CI: -0.20-0.25). Significant correlations were found between pre-PCI FFR and FFRCT(r = 0.53,p< .001), between post-PCI FFR and FFR(CT)planner (r = 0.41,p= .001), and between delta FFR and delta FFRCT(r = 0.57, p < .001). Conclusions The non-invasive FFR(CT)planner tool demonstrated significant albeit modest agreement with post-PCI FFR and change in FFR values after PCI. The FFR(CT)planner tool may hold promise for PCI procedural planning; however, improvement in technology is warranted before clinical application.