Change in Computed Tomography-Derived Fractional Flow Reserve Across the Lesion Improve the Diagnostic Performance of Functional Coronary Stenosis

Aims: This study sought to evaluate the diagnostic performance of change in computed tomography-derived fractional flow reserve (CT-FFR) across the lesion (ΔCT-FFR) for identifying ischemia lesions with FFR as the reference standard.Methods: Patients who underwent coronary CT angiography (CCTA) and FFR measurement within 1 week from December 2018 to December 2019 were retrospectively enrolled. CT-FFR within 2 cm distal to the lesion, ΔCT-FFR and plaque characteristics were analyzed. The diagnostic accuracy of CCTA (coronary stenosis ≥ 50%), CT-FFR ≤ 0.80, and ΔCT-FFR ≥ 0.15 (based on the largest Youden index) were assessed with FFR as the reference standard. The relationship between plaque characteristics and ΔCT-FFR was analyzed.Results: The specificity of ΔCT-FFR and CT-FFR were 70.8 and 67.4%, respectively, which were both higher than CCTA (39.3%) (both P < 0.001), while there were no statistical significance in sensitivity among the three (84.5, 77.4, 88.1%, respectively; P = 0.08). The area under the curves (AUCs) of ΔCT-FFR and CT-FFR were 0.803 and 0.743, respectively, which were both higher than that of CCTA (0.637) (both P < 0.05), and the AUC of ΔCT-FFR was higher than that of CT-FFR (P < 0.001). Multivariable analysis showed that low-attenuation plaque (LAP) volume (odds ratio [OR], 1.006) and plaque length (OR, 1.021) were independently correlated with ΔCT-FFR (both P < 0.05).Conclusions: CT-FFR and ΔCT-FFR and here especially the ΔCT-FFR could improve the diagnostic performance of ischemia compared with CCTA alone. LAP volume and plaque length were the independent risk factors of ΔCT-FFR.

Long-Term Clinical Outcomes of Fractional Flow Reserve-Guided Coronary Artery Revascularization in Chronic Kidney Disease

Fractional flow reserve (FFR)-guided percutaneous coronary intervention has shown favorable long-term clinical outcomes. However, limited data exist evaluating the FFR assessment among the chronic kidney disease (CKD) population. The aim of this study was to evaluate the long-term clinical outcomes of FFR-guided coronary revascularization in patients with CKD. A total of 242 CKD patients who underwent FFR assessment were retrospectively analyzed. Patients were divided into two groups: revascularization (FFR ≤ 0.80) and non-revascularization (FFR > 0.80). The primary endpoint was the composite of cardiac death, non-fatal myocardial infarction, and target vessel failure (TVF). The key secondary endpoint was TVF. The Cox regression model was used for risk evaluation. With 91% of the ischemic vessels revascularized, the revascularization group had higher risks for both the primary endpoint (adjusted hazard ratio [aHR]: 2.06; 95% confidence interval [CI], 1.07–3.97; p = 0.030) and key secondary endpoint (aHR: 2.19, 95% CI: 1.10–4.37; p = 0.026), during a median follow-up of 2.9 years. This result was consistent among different CKD severities. In patients with CKD, functional ischemia in coronary artery stenosis was associated with poor clinical outcomes despite coronary revascularization.

Comparison of Resting Full-Cycle Ratio and Fractional Flow Reserve in a German Real-World Cohort

Objective: The aim of this study was to evaluate non-hyperemic resting pressure ratios (NHPRs), especially the novel “resting full-cycle ratio” (RFR; lowest pressure distal to the stenosis/aortic pressure during the entire cardiac cycle), compared to the gold standard fractional flow reserve (FFR) in a “real-world” setting.Methods: The study included patients undergoing coronary pressure wire studies at one German University Hospital. No patients were excluded based on any baseline or procedural characteristics, except for insufficient quality of traces. The diagnostic performance of four NHPRs vs. FFR ≤ 0.80 was tested. Morphological characteristics of stenoses were analyzed by quantitative coronary angiography.Results: 617 patients with 712 coronary lesions were included. RFR showed a significant correlation with FFR (r = 0.766, p < 0.01). Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of RFR were 78% (95% confidence interval = 75; 81), 72% (65; 78), 81% (77; 84), 63% (57; 69), and 86% (83; 89). Relevant predictors for discordance of RFR ≤ 0.89/FFR > 0.8 were LAD lesions, peripheral artery disease, age, female sex and non-focal stenoses. Predictors for discordance of RFR > 0.89/FFR ≤ 0.8 included non-LCX lesions, percent diameter stenosis and previous percutaneous coronary intervention in the target vessel. RFR and all other NHPRs were highly correlated with each other.Conclusion: All NHPRs have a similar correlation with the gold standard FFR and may facilitate the acceptance and implementation of physiological assessments of lesion severity. However, we found ~20% discordant results between NHPRs and FFR in our “all-comers” German cohort.

Fractional Flow Reserve in the Diagnosis of Ischemic Heart Disease in a Patient with Coronary Artery Ectasia

Coronary artery ectasias (CAE) are diffuse dilatations of coronary artery segments with a diameter 1.5 times greater than the largest adjacent normal segment of the vessel. They are found in 0.3–5.0% of coronary angiography. Risk factors for CAE include atherosclerosis, previous percutaneous coronary interventions, arterial inflammation and connective tissue diseases. The diagnosis of CEA in a patient is a considerable diagnostic and therapeutic problem due to the unfavorable prognosis and the lack of guidelines. We present a case of a 69-year-old male patient with a history of retrosternal pain admitted to the clinic for the diagnosis of coronary artery disease. In coronary angiography, numerous ectases of the main coronary arteries and atherosclerotic lesions causing border stenosis of the left anterior descending (LAD), diagonal (2D) and marginal branch (OM). The heart team decided to assess the significance of the changes with the fractional flow reserve (FFR). The FFR was performed and haemodynamically insignificant stenoses of the ectatically dilated coronary arteries were found. The patient was qualified for conservative treatment.