scholarly journals Coronary artery stenosis-related perfusion ratio using dynamic computed tomography myocardial perfusion imaging: a pilot for identification of hemodynamically significant coronary artery disease

2019 ◽  
Vol 35 (4) ◽  
pp. 327-335 ◽  
Author(s):  
Natsumi Kuwahara ◽  
Yuki Tanabe ◽  
Teruhito Kido ◽  
Akira Kurata ◽  
Teruyoshi Uetani ◽  
...  

Abstract The purpose of this study was to evaluate the feasibility of the stenosis-related quantitative perfusion ratio (QPR) for detecting hemodynamically significant coronary artery disease (CAD). Twenty-seven patients were retrospectively enrolled. All patients underwent dynamic myocardial computed tomography perfusion (CTP) and coronary computed tomography angiography (CTA) before invasive coronary angiography (ICA) measuring the fractional flow reserve (FFR). Coronary lesions with FFR ≤ 0.8 were defined as hemodynamically significant CAD. The myocardial blood flow (MBF) was calculated using dynamic CTP data, and CT-QPR was calculated as the CT-MBF relative to the reference CT-MBF. The stenosis-related CT-MBF and QPR were calculated using Voronoi diagram-based myocardial segmentation from coronary CTA data. The relationships between FFR and stenosis-related CT-MBF or QPR and the diagnostic performance of the stenosis-related CT-MBF and QPR were evaluated. Of 81 vessels, FFR was measured in 39 vessels, and 20 vessels (51%) in 15 patients were diagnosed as hemodynamically significant CAD. The stenosis-related CT-QPR showed better correlation (r = 0.70, p < 0.05) than CT-MBF (r = 0.56, p < 0.05). Sensitivity and specificity for detecting hemodynamically significant CAD were 95% and 58% for CT-MBF, and 95% and 90% for CT-QPR, respectively. The area under the receiver operating characteristic curve for the CT-QPR was significantly higher than that for the CT-MBF (0.94 vs. 0.79; p < 0.05). The stenosis-related CT-QPR derived from dynamic myocardial CTP and coronary CTA showed a better correlation with FFR and a higher diagnostic performance for detecting hemodynamically significant CAD than the stenosis-related CT-MBF.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Ray ◽  
K Green ◽  
A Shamsi ◽  
A Mahmood ◽  
A Hatrick ◽  
...  

Abstract   Background/Introduction - Fractional flow reserve (FFR), a pressure wire-based index used during coronary angiography to assess the severity of potential coronary stenosis, is considered as the reference standard for evaluating the severity of stenosis in coronary artery disease (CAD). Recently, computed tomography angiography-derived fractional flow reserve (FFRct) has been recommended for evaluating functional severity of stenoses as it improves diagnostic accuracy and reduces the need for invasive coronary angiography. Purpose To determine whether non-invasive FFRct predicts severity of coronary artery disease and whether its addition improves efficiency of proceeding to revascularisation and invasive coronary angiography (ICA) compared to coronary computed tomography angiography (CTA) without FFR. Methods This observational retrospective single center study included two cohorts of patients who presented in a District General Hospital in UK. The first group consisted of all patients who underwent coronary CTA for chest pain from January 2013 to December 2014. The second cohort consisted of all patients who proceeded to have measurement of FFRct from April 2018 to June 2019 after routine coronary CTA for chest pain. The two groups showed similar demographics. FFRct was analysed using the software HeartFlow. We determined the agreement of FFRct (positive if &lt;0.80) with stenosis on CTA and ICA (positive if &gt;50% left main or &gt;70% other coronary artery) and whether it correlated with need for revascularisation. We also assessed if adding FFRct &lt;0.80 improved efficiency of referral to ICA, defined as decreased diagnosis of mild or moderate stenosis (&lt;70%) and higher yield of severe disease (&gt;70%). The two cohorts were compared to determine the above specific end-points. Results In the first cohort, data was collected for 915 patients. 240 (26.2%) of these patients proceeded to ICA, which showed severe disease in 31 (3.3%) patients needing revascularisation. In the second cohort of patients, 824 patients underwent coronary CTA and 201 (24.4%) proceeded to have FFRct measurements. 99 (49%) of these patients had a negative FFR and 65 (32%) patients had a positive result (&lt;0.80). There was agreement between FFRct and invasive coronary angiography/stress echo in 44 (77%) patients, with regards to severity /revascularisation. The need for ICA was significantly reduced if coronary CTA and FFRct were both done (240/915; 26.2% vs 54/824; 6.5%: p value &lt;0.00001). Conclusion Reserving ICA for patients with a positive FFRct (&lt;0.80) could reduce the number of ICA after coronary CTA and augment the number of ICA leading to revascularisation. Use of FFRct as a gatekeeper to ICA will improve appropriate selection of patients referred and this in-turn will reduce the burden of complications associated with invasive procedures, reduce costs and ensure better utilization of Cath-lab resources. Funding Acknowledgement Type of funding source: None


Author(s):  
J. Peper ◽  
J. Schaap ◽  
B. J. W. M. Rensing ◽  
J. C. Kelder ◽  
M. J. Swaans

Abstract Purpose Invasive fractional flow reserve (FFR), the reference standard for identifying significant coronary artery disease (CAD), can be estimated non-invasively by computed tomography-derived fractional flow reserve (CT-FFR). Commercially available off-site CT-FFR showed improved diagnostic accuracy compared to coronary computed tomography angiography (CCTA) alone. However, the diagnostic performance of this lumped-parameter on-site method is unknown. The aim of this cross-sectional study was to determine the diagnostic accuracy of on-site CT-FFR in patients with suspected CAD. Methods A total of 61 patients underwent CCTA and invasive coronary angiography with FFR measured in 88 vessels. Significant CAD was defined as FFR and CT-FFR below 0.80. CCTA with stenosis above 50% was regarded as significant CAD. The diagnostic performance of both CT-FFR and CCTA was assessed using invasive FFR as the reference standard. Results Of the 88 vessels included in the analysis, 34 had an FFR of ≤ 0.80. On a per-vessel basis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 91.2%, 81.4%, 93.6%, 75.6% and 85.2% for CT-FFR and were 94.1%, 68.5%, 94.9%, 65.3% and 78.4% for CCTA. The area under the receiver operating characteristic curve was 0.91 and 0.85 for CT-FFR and CCTA, respectively, on a per-vessel basis. Conclusion On-site non-invasive FFR derived from CCTA improves diagnostic accuracy compared to CCTA without additional testing and has the potential to be integrated in the current clinical work-up for diagnosing stable CAD.


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