Research Presentation Session
04:34G. Tessarin, Padua / IT
Purpose:
Observational cohort study evaluating neutrophil extracellular traps (NET)-osis' activation in patients with acute coronary syndrome and in patients with and without coronary artery disease investigated with coronary CT angiography.
Methods and materials:We enrolled 27 patients with an acute coronary syndrome (ACS), 86 patients with non-complicated coronary artery disease (CAD) diagnosed with coronary computed tomography angiography, and 114 patients with no CT signs of coronary artery disease from March 2016 to October 2017. Each patient underwent blood sampling to assess circulating markers of NETosis, such as lactoferrin, proteinase PR3, PMN elastase, and neutrophil gelatinase-associated lipocalin (NGAL). The circulating levels of these markers were then compared between the three groups of patients.
Results:Increased levels of neutrophils and decreased levels of lymphocytes (p<0.001) were found in patients with acute coronary syndrome compared to the other two populations. Analysis of NETosis's markers showed a significant increase of NGAL and PMN-Elastase in ACS patients compared to the ones with NO-CAD (respectively, p=0.005 and p=0.009) and with CAD (respectively, p=0.002 and p=0.010). A significant increase of lactoferrin was also recorded in CAD versus NO-CAD populations (p=0.014). No significant differences for PR3 were found. Furthermore NGAL plasmatic levels resulted independently associated to ACS presence (p=0.013) also after traditional risk factors adjustment.
Conclusion:This study showed a significant increased level of some NETosis’ markers in subjects with ACS compared to patients with and without CAD, suggesting a role of neutrophils activation in atherothrombotic complications of atherosclerosis.
Limitations:A limited number of patients analysed, especially patients with acute coronary syndrome.
Ethics committee approvalApproval of the ethics committee for the clinical trial of provinces of Treviso and Belluno (Italy). Written informed consent acquired.
Funding:No funding was received for this work.
05:49R. Ma, Groningen / NL
Purpose:
To investigate differences in fat attenuation index (FAI) between coronary arteries with and without plaque and relationships with plaque morphology.
Methods and materials:We retrospectively investigated 165 patients with clinically indicated cCTA between January 2015 and November 2017 (72 patients without and 93 patients with plaque). Scanning involved 3rd generation dual-source CT (SOMATOM Force, Siemens Healthineers) at 70kV. For healthy coronary arteries, FAI was measured at the proximal coronary segment. For diseased coronary arteries, FAI was measured across the plaque-causing most luminal narrowing. The first regression model compared FAI in healthy and diseased coronary arteries. A second model, including only diseased coronary arteries, evaluated the relationship of plaque-type and stenosis severity with FAI. Plaque type was divided into non-calcified, mixed, and calcified. Stenosis severity was categorised as minimal (1-24%), mild (25-49%), moderate (50-69% ), and severe (70-100%).
Results:FAI in healthy and diseased coronary arteries were -98.0±10.1HU versus -100.5±10.1HU, -93.9±8.5HU versus -91.4±11.2HU, and -96.1±9.0HU versus -93.7±10.8HU for LAD, LCX, and RCA, respectively. There was a significant difference in FAI between healthy vessels and diseased vessels (p=0.018). FAI of non-calcified, mixed, and calcified plaque was -90.7±12.0HU, -95.0±10.5HU, and -97.9±10.8HU, with a significant difference between FAI of non-calcified and calcified plaque (p=0.025) and between non-calcified and mixed plaque (p<0.001). FAI of minimal, mild, moderate, and severe stenosis was -94.7±10.6HU, -95.5±11.2HU, -95.8±11.9HU, and -99.1±12.0HU. FAI was significantly different between minimal/mild and severe stenosis (p=0.011/0.016).
Conclusion:FAI showed differences by coronary plaque composition and degree of stenosis. These results may offer insight into the development of coronary artery disease and plaque vulnerability.
Limitations:The study lacked pathology results.
Ethics committee approvalThe Medical Ethical Board waived the need for informed consent.
Funding:The first author was sponsored by the China Scholarship Council.
07:22P. Palumbo
06:19G. Muscogiuri, Milan / IT
Purpose:
To develop a deep convolutional neural network (CNN) to classify coronary computed tomography angiography (CCTA) in the correct coronary artery disease reporting and data system (CAD-RADS) category.
Methods and materials:288 patients who underwent clinically indicated CCTA were included in this single-centre retrospective study. The CCTAs were stratified by CAD-RADS scores by expert readers and considered as a reference standard. A deep CNN was designed and tested on the CCTA dataset and compared to on-site reading. The deep CNN analysed the diagnostic accuracy of the following three models based on CADRADS classification: Model A (CADRADS 0 vs CADRADS 1-2 vs CADRADS 3,4,5), Model 1 (CADRADS 0 vs CADRADS>0), and Model 2 (CADRADS 0-2 vs CADRADS 3-5). The time of analysis for both physicians and CNN were recorded.
Results:Model A showed a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 47%, 74%, 77%, 46%, and 60%, respectively. Model 1 showed a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 66%, 91%, 92%, 63%, 86%, and 89%, respectively. Conversely, Model 2 demonstrated the following sensitivity, specificity, negative predictive value, positive predictive value, and accuracy: 82%, 58%, 74%, 69%, 71%, and 78%, respectively. Time of analysis was significantly lower using CNN as compared to on-site reading (530.5±179.1vs104.3±1.4 seconds, p:0.01).
Conclusion:Deep CNN yielded accurate automated classification of patients with CAD-RADS.
Limitations:A small sample size was used for the study.
Ethics committee approvalIn process.
Funding:No funding was received for this work.
06:04R. Bayer, Charleston / US
Purpose:
Fractional flow reserve derived from coronary CTA (FFR-CT) has demonstrated utility in the evaluation of coronary artery disease in stable outpatients. However, the utility of FFR-CT in the emergency department (ED) setting in patients with acute chest pain (ACP) is insufficiently studied. We evaluated 30-day clinical outcomes (major adverse cardiovascular events (MACE), revascularisation, and readmission) in patients presenting to the ED with ACP.
Methods and materials:Patients between the ages of 18-95 years who presented to our ED with ACP and underwent clinically indicated cCTA and FFR-CT were included. cCTA was acquired using 3rd generation dual-source CT and FFR-CT was performed HearFlow®. Patients were retrospectively evaluated for 30-day MACE, readmission, revascularisation, and additional testing.
Results:A total of 59 patients underwent CCTA and subsequent FFRCT. 32 out of 59 patients (54%) had negative FFRCT (≥0.80) out of whom 18 patients (55%) were discharged from the ED. Out of the 32 patients without functionally significant CAD by FFRCT, 32 patients (100%) underwent no revascularisation and 32 patients (100%) had no MACE at the 30-day follow-up period. Conversely, there were 3 MACE in the group of 27 patients with an FFRCT <0.8. The average turnaround time for FFRCT results was 3.5 hrs.
Conclusion:This preliminary data demonstrates that cCTA and subsequent FFRCT has the potential for accurate and safe evaluation of CAD in patients presenting to the ED with acute chest pain. In this small cohort of patients, FFRCT yielded a negative predictive value of 100%.
Limitations:The limitations of the study included a small sample size at a single centre. The high disease prevalence and severe may have resulted in selection bias.
Ethics committee approvalIRB approval with waiver of consent.
Funding:Research support provided by HeartFlow.
05:43S. Martin, Frankfurt / DE
Purpose:
Coronary artery disease reporting and data system (CAD-RADS) is a standardised classification system for coronary CT angiography (CCTA). We aimed to investigate the impact of fractional flow reserve (FFRCT) derived from CCTA on CAD-RADS stratifications in patients presenting with acute chest pain (ACP).
Methods and materials:FFRCT analysis was included in the diagnostic workup of 94 patients (mean age 65.7±9.6 years) who presented to the emergency department (ED) with ACP and were referred for CCTA. We evaluated the rate of CAD-RADS reclassifications from the initial interpretation of the CCTA study alone versus after FFRCT results were obtained. Other reported data included downstream resource use and 90-day clinical outcomes.
Results:3 patients were initially classified as CAD-RADS 1, 18 as CAD-RADS 2, 44 as CAD-RADS 3, and 29 as CAD-RADS 4 based on CCTA alone. No patient with an initial CAD-RADS 1, 2, or 4 classification was reclassified following the addition of FFRCT results. However, in patients with CAD-RADS 3, where function testing is often recommended for further evaluation, 41% (18/44) were reclassified to CAD-RADS 2 after FFRCT results were obtained. This assessment may decrease the rate of additional diagnostic testing by 64%. Additionally, no clinical events occurred in the group of patients with FFRCT >0.80 at 90-day follow up.
Conclusion:Adding FFRCT analysis in patients presenting with ACP substantially decreases equivocality in CCTA interpretation, drastically reduces CAD-RADS 3 classifications, and has the potential to obviate unnecessary downstream testing. One should consider an update to the CAD-RADS classification to account for the availability of FFRCT.
Limitations:Single-centre, short follow-up time, small sample.
Ethics committee approvalIRB-approved. Informed consent waived.
Funding:No funding was received for this work.