Diagnostic accuracy of a novel optical coherence tomography-based fractional flow reserve algorithm for assessment of coronary stenosis significance.

BACKGROUND: This study aimed to introduce a novel optical coherence tomography-derived fractional flow reserve (FFR) computational approach and assess the diagnostic performance of the algorithm for assessing physiological function. METHODS: The fusion of coronary optical coherence tomography and angiography was used to generate a novel FFR algorithm (AccuFFRoct) to evaluate functional ischemia of coronary stenosis. In the current study, a total of 34 consecutive patients were included, and AccuFFRoct was used to calculate the FFR for these patients. With the wire-measured FFR as the reference standard, we evaluated the performance of our approach by accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: Per vessel accuracy, sensitivity, specificity, PPV, and NPV for AccuFFRoct in identifying hemodynamically significant coronary stenosis were 93.8%, 94.7%, 92.3%, 94.7%, and 92.3%, respectively, were found. Good correlation (Pearson's correlation coefficient r = 0.80, p < 0.001) between AccuFFRoct and FFR was observed. The Bland-Altman analysis showed a mean difference value of -0.037 (limits of agreement: -0.189 to 0.115). The area under the receiver-operating characteristic curve (AUC) of AccuFFRoct in identifying physiologically significant stenosis was 0.94, which was higher than the minimum lumen area (MLA, AUC = 0.91) and significantly higher than the diameter stenosis (%DS, AUC = 0.78). CONCLUSIONS: This clinical study shows the efficiency and accuracy of AccuFFRoct for clinical implementation when using invasive FFR measurement as a reference. It could provide important insights into coronary imaging superior to current methods based on the degree of coronary artery stenosis.

Functional Assessment of Coronary Artery Stenosis from Coronary Angiography and Computed Tomography: Angio-FFR vs. CT-FFR.

This study was designed to compare the diagnostic performance of angio-FFR and CT-FFR for detecting hemodynamically significant coronary stenosis. Angio-FFR and CT-FFR were measured in 110 patients (139 vessels) with stable coronary disease using invasive FFR as the reference standard. On per-patient basis, angio-FFR was highly correlated with FFR (r =0.78, p <0.001), while the correlation was moderate between CT-FFR and FFR (r =0.68, p <0.001). Diagnostic accuracy, sensitivity, and specificity for angio-FFR were 94.6%, 91.4%, and 96.0%, respectively; and those of CT-FFR were 91.8%, 91.4%, and 92%, respectively. Bland-Altman analysis showed that angio-FFR had a larger average difference and a smaller root mean squared deviation than CT-FFR compared with FFR (-0.014±0.056 vs. 0.0003±0.072). Angio-FFR had a slightly higher AUC than that of CT-FFR (0.946 vs. 0.935, p =0.750). Angio-FFR and CT-FFR computed from coronary images could be accurate and efficient computational tools for detecting lesion-specific ischemia of coronary artery stenosis. Angio-FFR and CT-FFR calculated based on the two types of images can both accurately diagnose functional ischemia of coronary stenosis. CT-FFR can act as a gatekeeper to the catheter room, assisting doctors in determining whether patients need to be screened by coronary angiography. Angio-FFR can be used in the catheter room to determine the functional significant stenosis for helping decision-making in revascularization.

Diagnostic performance of AccuFFRangio in the functional assessment of coronary stenosis compared with pressure wire-derived fractional flow reserve.

BACKGROUND: Non-invasive fractional flow reserve (FFR) has been increasingly used in the clinical workflow to assist clinical decision-making for percutaneous coronary intervention (PCI). This clinical study evaluates the diagnostic accuracy of coronary stenosis assessed by a non-invasive FFR analysis method (termed AccuFFRangio) based on invasive coronary angiography (ICA). It is a blinded, self-controlled, retrospective, and dual-center clinical investigation study. METHODS: Coronary angiography data and the related information of 320 patients with 320 vessels were collected, and AccuFFRangio was used to assess the FFR for these patients. Compared with the wire-measured FFR values, we evaluated AccuFFRangio performance by its accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: The diagnostic accuracy, sensitivity, specificity, PPV, and NPV for AccuFFRangio in identifying hemodynamically significant coronary stenosis were 93.3%, 92.6%, 93.5%, 84.3%, and 97.1%, respectively. The direct correlation between computed AccuFFRangio and measured FFR was 0.812 (P<0.001), and the area under the receiver operating characteristic curve (AUC) value of AccuFFRangio was 0.96. CONCLUSIONS: This clinical study demonstrates the efficiency and accuracy of AccuFFRangio for clinical implementation when using invasive wire-measured FFR as a reference. Further validation is required in a large prospective multicenter study.

Fractional flow reserve for coronary stenosis assessment derived from fusion of intravascular ultrasound and X-ray angiography.

BACKGROUND: Intravascular ultrasound (IVUS) provides good insight into lumen boundary and plaques; however, it is still difficult to detect functionally significant stenosis from IVUS images for the guidance of coronary percutaneous intervention (PCI). This study aimed to develop a novel method to estimate fractional flow reserve (FFR) value for determining the functional significance of coronary artery disease through the fusion of IVUS and X-ray angiographic images. METHODS: We developed a novel approach to 3D vessel reconstruction by integrating IVUS with X-ray angiographic images. Based on the reconstructed geometry and the inlet flow derived from the thrombolysis in myocardial infarction (TIMI) frame count, a simplified fluid dynamics equation was established to compute the pressure drop and IVUS-derived FFR (AccuFFRivus) was subsequently obtained. To validate the feasibility and performance of this IVUS-based FFR method, we performed AccuFFRivus calculations on 32 coronary vessels with invasive FFR as the reference standard. RESULTS: Great correlation (r=0.86, P<0.001) was observed between AccuFFRivus and FFR. The area under the receiver-operating characteristic curve (AUC) was higher for AccuFFRivus than minimal lumen area (MLA, <4 mm2) and diameter stenosis rate (DS% ≥50%) [0.98 (95% CI: 0.86 to 1.0) vs. 0.78 (95% CI: 0.60 to 0.91) and 0.66 (95% CI: 0.47 to 0.82)]. Bland-Altman plot showed a mean difference value of -0.011 (limits of agreement: -0.156 to 0.134). CONCLUSIONS: AccuFFRivus is a novel method for hybridizing IVUS and X-ray angiographic images to identify functionally significant stenosis with FFR ≤0.80. The good diagnostic performance from the initial validation study demonstrates the potential for clinical utilization of physiologically guided decision-making. Further validation is required in future studies with a large number of cases.

Fractional Flow Reserve Guided Percutaneous Coronary Intervention Improves Clinical Outcome with Reduced Cost in Contemporary Clinical Practice.

BACKGROUND: Fractional flow reserve (FFR) is currently considered as the gold standard for evaluating the functional significance of coronary stenosis. However, its potential benefits in real-world practice remain unknown in China. This study aimed to test the hypothesis that the use of FFR is associated with improved outcome and reduced cost in Chinese real-world clinical practice. METHODS: A retrospective cohort study was carried out using the database of Second Affiliated Hospital of Zhejiang University, a tertiary and high-volume center in China. Clinical events were compared using the Cox proportional hazards model during a median follow-up of 13 months. RESULTS: The study cohort consisted of 366 consecutive patients referred for coronary revascularization with adjunct FFR and 366 matched controls, from 2010 to 2014. Major adverse cardiac events (MACEs) (death, myocardial infarction, repeated revascularization, or hospitalization for angina) at 4 years were found in 12.0% of angiography-guided patients and 4.9% in the FFR-guided group (P < 0.001). The mean number of implanted stents was significantly lower in FFR treated subjects (0.52 ± 0.82 stents) compared with the angiography-guided group (0.93 ± 0.96 stents) (P < 0.001). No difference in overall costs at initial hospitalization was observed between angiography-guided percutaneous coronary intervention (PCI) compared with FFR-guided PCI (RMB 33,000 Yuan, range: RMB 7393-44,700 Yuan) versus RMB 21,200 Yuan (RMB 19,100-47,100 Yuan) (P = 0.54). However, costs for MACEs during follow-up were significantly reduced in the FFR-guided arm (P < 0.001). CONCLUSIONS: In the contemporary clinical practice, FFR-guided PCI is associated with decreased use of stents, improved clinical outcome, and reduced costs, compared with angiography-guided PCI.

[Assessment on anti-nociception and anti-inflammation pharmacodynamics of Asarum heterotropoides var. mandshuricum and Asarum sieboldii].

OBJECTIVE: To assess the anti-nociception and anti-inflammation pharmacodynamics of Asarum heterotropoides var. mandshuricum and A. sieboldii. METHOD: Both the writhing test and hot plate test were conducted to assess the anti-nociceptive effect of Asarum and Xylene-induced mouse ear edema was conducted to assess the anti-inflammatory effect of Asarum. RESULT: Twelve samples of A. heterotropoides var. mandshuricum and A. sieboldii from different producing areas showed anti-nociceptive and anti-inflammatory effects. Specifically, 27% to 61% of the seven samples of A. heterotropoides var. mandshuricum showed anti-nociceptive effect and while 34% to 48% of A. sieboldi showed anti-nociceptive effect. The inflammatory inhibition rate of A. heterotropoides var. mandshuricum produced in six producing areas (38%-57%) is higher than that of A. heterotropoides var. mandshuricum produced in five producing areas (34%-48%). The same kind of Asarum produced in different areas showed significant differences. A. heterotropoides var. mandshuricum produced in Jilin province (38%-57%) showed better anti-nociceptive effect than sample produced in Heilongjiang province (34%) in writhing test. A. heterotropoides var. mandshuricum produced in Heilongjiang (43%) province showed a better anti-nociceptive effect than samples produced in Liaoning province (29%-36%) in hot plate test. A. sieboldii produced in Shaanxi province (47%-49%) showed a better anti-nociceptive effect than samples produced in Hubei province (40%) in writhing test. A. sieboldii produced in Shaanxi province (45%-59%) showed better anti-nociceptive effect than samples produced in Chongqing (40%) in hot plate test. A. heterotropoides var. mandshuricum produced in Jilin province (51%-63%) showed better anti-inflammatory effect than samples produced in Heilongjiang province (50%). In totality, the results from analysis of geoherbalism showed that famous-region A. heterotropoides var. mandshuricum and A. sieboldii had a better anti-nociception effect than Asarum produced in other producing areas, famous-region A. heterotropoides var. mandshuricum had a better effect than those produced in other producing areas in anti-inflammation. But famous-region A. sieboldii showed no obvious difference from those produced in other producing areas in anti-inflammation. CONCLUSION: All samples of Asarum showed anti-nociceptive and anti-inflammatory effects, but with significant differences among Asarum produced in different areas, indicating the eoherbalism to some extent.