Detection Of Significant Coronary Stenosis Research Articles

Abstract 16473: Validation of the Artificial Intelligence-Based 5-Lead 3D Vectorcardiography in Comparison to the 12-Lead ECG in a Mixed Population

Introduction: Artificial Intelligence-based 5-lead 3D-vectorcardiography (5L3DVCG-AI) offers additional information over 12-lead electrocardiography (ECG) in the detection of significant coronary stenoses. 5L3DVCG-AI is under investigation as a new screening tool for coronary vascular disease (CVD). Hypothesis: We tested the hypothesis of variables from the reconstructed “12-lead ECG” (5L12L-ECG, modified Dower transformation) corresponding with the standard 12-lead ECG (ECG). Methods: In this monocentric exploratory retrospective study, raw data of 331 patients with 5L3DVCG-AI and ECG were included. Cardiac pathology (CP) was categorised as exclusion of any CP (control), mild CP or overt CP by 2 independent cardiologists. The following variables were compared: RR-interval, P, PQ, QRS, QT, QTcB, QTcF, QRS-morphology, and ST-morphology. Cardiovascular risk factors (CVRF) were quantified with the modified PROCAM score. Results: From 331 patients (m:w 60:40%, 50.0 ± 19.8 years) of mixed ethnicity and moderate CVRF (2.1 ± 1.2), 70% were controls, 21% had mild CP and 9% overt CP. All variables from reconstructed 5L12L-ECG correlated to the corresponding individual variables from ECG (r= 0.49 to 0.7, p<0.001). With identical RR-intervals in both methods, all defined variables were significantly, but irrelevantly or mildly (Cohen’s d) different in 5L12L-ECG compared to ECG (P 106 ± 12 vs. 109 ±20 ( d =0.3), PQ 152 ± 24 vs. 159 ± 26 ( d =0.3), QRS 105 ± 16 vs. 97 ± 14 ( d =0.7), QT 380 ± 33 vs. 396 ± 27 ( d =0.46), QTcB 432 ± 31 vs. 426 ± 25 ( d =0.57), QTcF 414 ± 26 vs. 416 ± 19 ( d =0.53). 5L3DVCG-AI was able to distinguish between controls and patients with CVD (Sensitivity 78%, Specificity 66%, p=0.01). Comparing heart axis, there was a small, but significant difference with a significant correlation between methods (r=0.30, p<0.01). Conclusions: The easy to use 5-lead ECG may thus be used in clinical practice to reconstruct valid 12-lead ECG curves without major training or expertise. Additionally, 5L3DVCG-AI can identify persons at risk for CVD. Shorter values for the defined variable will have to be considered when interpreting 5L12L-ECG and separate “normal” value ranges will be given and validated in the ongoing prospective large-scale performance clinical trials.

The feasibility, reliability, and incremental value of two-dimensional speckle-tracking for the detection of significant coronary stenosis after treadmill stress echocardiography

BackgroundTwo-dimensional speckle-tracking echocardiography (STE) may help detect coronary artery disease (CAD) when combined with dobutamine stress echocardiography. However, few studies have explored STE with exercise stress echocardiography (ESE). We aimed to evaluate the feasibility, reliability, and incremental value of STE combined with treadmill ESE compared to treadmill ESE alone to detect CAD.MethodsWe conducted a case–control study of all consecutive patients with abnormal ESE in 2018–2020 who subsequently underwent coronary angiography within a six-month interval. We 1:1 propensity score-matched these patients to those with a normal ESE. Two blinded operators generated a 17-segment bull's-eye map of longitudinal strain (LS). We utilized the mean differences between stress and baseline LS values in segments 13–17, segment 17, and segments 15–16 to create receiver operator curves for the overall examination, the left anterior descending artery (LAD), and the non-LAD territories, respectively.ResultsWe excluded 61 STEs from 201 (30.3%) eligible ESEs; 47 (23.4%) because of suboptimal image quality and 14 (7.0%) because of excessive heart rate variability precluding the calculation of a bull's-eye map. After matching, a total of 102 patients were included (51 patients in each group). In the group with abnormal ESE patients (mean age 66.4 years, 39.2% female), 64.7% had significant CAD (> 70% stenosis) at coronary angiogram. In the group with normal ESE patients (mean age 65.1 years, 35.3% female), 3.9% were diagnosed with a new significant coronary stenosis within one year. The intra-class correlation for global LS was 0.87 at rest and 0.92 at stress, and 0.84 at rest, and 0.89 at stress for the apical segments. The diagnostic accuracy of combining ESE and STE was superior to visual assessment alone for the overall examination (area under the curve (AUC) = 0.89 vs. 0.84, p = 0.025), the non-LAD territory (AUC = 0.83 vs. 0.70, p = 0.006), but not the LAD territory (AUC = 0.79 vs. 0.73, p = 0.11).ConclusionsTwo-dimensional speckle-tracking combined with treadmill ESE is relatively feasible, reliable, and may provide incremental diagnostic value for the detection and localization of significant CAD.

Coronary artery calcium score above 250 confirms the presence of significant stenosis in coronary CT angiography of symptomatic patients.

Evaluation of coronary artery calcium score (CACS) at multiple low and high cutoff values for the detection of significant coronary stenosis at two different cutoffs (50 and 70%) in a large number of symptomatic patients was not investigated previously in one study. This study aims to investigate if there are a correlation and statistical significance between different CACS cutoffs and the severity of coronary artery stenosis by coronary CT angiography (CCTA) in symptomatic patients. This is a retrospective study that included all symptomatic patients who had CCTA in a tertiary care hospital over a period of 7 years. CCTA of 502 patients was evaluated (406 included, mean age 56.2 years); 230 were males (56.7%). The prevalence of stenosis at any percentage was 53.7%, ≥50% was 26.6% and ≥70% was 12.3%. The mean CACS was 84.5 (range 0-1860), for males was 124.5 and for females was 32.1. Patients with CACS of zero (59%) and CACS of ≥1 (41%) had a mean stenosis of 8.9% (range 0-75%) and 52.6% (range 0-100%), respectively. All patients with a CACS of ≥250 were found to have ≥50% stenosis (100% specificity and positive predictive value, 35.2% sensitivity, 81% negative predictive value and 82.6% accuracy). The percentage of stenosis increased as CACS increased with strong statistical significance (P value < 0.0001) and a positive correlation (r = 0.58). CACS is a valuable diagnostic tool to predict the severity of coronary artery stenosis. A cutoff value of 250 confirmed the presence of at least 50% stenosis in symptomatic patients.

Coronary computed tomography angiography using model-based iterative reconstruction algorithms in the detection of significant coronary stenosis: how the plaque type influences the diagnostic performance.

PurposeTo evaluate the ability of coronary computed tomography angiography (CCTA) with model-based iterative reconstruction (MBIR) algorithm in detecting significant coronary artery stenosis compared with invasive coronary angiography (ICA).Material and methodsWe retrospectively identified 55 patients who underwent CCTA using the MBIR algorithm with evidence of at least one significant stenosis (≥ 50%) and an ICA within three months. Patients were stratified based on calcium score; stenoses were classified by type and by coronary segment involved. Dose-length-product was compared with the literature data obtained with previous reconstruction algorithms. Coronary artery stenosis was estimated on ICAs based on a qualitative method.ResultsCCTA data were confirmed by ICA in 89% of subjects, and in 73% and 94% of patients with CS < 400 and ≥ 400, respectively. ICA confirmed 81% of calcific stenoses, 91% of mixed, and 67% of soft plaques. Both the dose exposure of patients with prospective acquisition (34) and the exposure of the whole population were significantly lower than the standard of reference (p < 0.001 and p = 0.007).ConclusionsCCTA with MBIR is valuable in detecting significant coronary artery stenosis with a solid reduction of radiation dose. Diagnostic performance was influenced by plaque composition, being lower compared with ICA for patients with lower CAC score and soft plaques; the visualisation of an intraluminal hypodensity could cause false positives, particularly in D1 and MO segments.

CT Angiography for the Detection of Coronary Artery Stenoses in Patients Referred for Cardiac Valve Surgery: Systematic Review and Meta-Analysis

ObjectivesThis study aimed to evaluate the diagnostic accuracy of coronary computed tomography angiography (CTA) for detecting coronary artery stenoses in patients with valvular heart disease undergoing valve surgery. BackgroundCoronary CTA is currently not routinely recommended for detecting coronary artery stenoses before cardiac valve surgery. However, recent improvements in computed tomography technology may enable the identification of the most appropriate candidates for coronary CTA before valve surgery. MethodsA systematic review was performed of PubMed, EMBASE, and the Cochrane databases for all studies that used ≥16-detector row computed tomography scanning to perform coronary CTA in patients with valvular heart disease scheduled for valve surgery and validated the results against invasive angiography. Summary diagnostic accuracies were calculated by using a bivariate random effects model, and a generalized linear mixed model was applied for heterogeneity analysis. ResultsSeventeen studies analyzing 1,107 patients and 12,851 coronary segments were included. Patient-based analysis revealed a pooled sensitivity of 93% (95% confidence interval [CI]: 86 to 97), specificity of 89% (95% CI: 86 to 91), a negative likelihood ratio (LR) of 0.07 (95% CI: 0.04 to 0.16), and a positive LR of 8.44 (95% CI: 6.49 to 10.99) for coronary CTA to identify individuals with stenosis ≥50%. Specificity and positive LR were higher in patients without aortic stenosis (AS) versus those with AS (96% vs. 87% and 21.2 vs. 7.4, respectively), as well as with ≥64 detectors versus <64 detectors (90% vs. 86% and 9.5 vs. 6.9). Heterogeneity analysis revealed a significant impact of AS and the number of detectors on specificity of CTA. ConclusionsCoronary CTA using currently available technology is a reliable imaging alternative to invasive angiography with excellent sensitivity and negative LR for the detection of significant coronary stenoses in patients undergoing cardiac valve surgery. The specificity of coronary CTA may be decreased against the background of AS (Computed Tomography Angiography for the Detection of Coronary Artery Disease in Patients Referred for Cardiac Valve Surgery: A Meta-Analysis; CRD42015016213)

Segmental quantitative myocardial perfusion with PET for the detection of significant coronary artery disease in patients with stable angina.

The goal of this study is to determine the technical accuracy of segmental perfusion parameters assessed with quantitative cardiac PET imaging in the evaluation of coronary artery disease (CAD) in patients with stable angina. A cohort of patients who participated in the EVINCI protocol underwent an evaluation of coronary anatomy by invasive coronary angiography (ICA) and/or coronary computed tomography angiography (CCTA) and PET myocardial perfusion imaging with H2 (15)O, (13)NH3 or (82)Rb. PET studies were analyzed by two independent observers blinded to clinical and instrumental data, and classified as positive or negative for significant CAD using only segmental perfusion measurements and cut-off values from literature. On a per-patient basis, the overall inter-observer agreement on PET results was 90% (kappa = 0.79), indicating substantial agreement. On a per-vessel basis, the inter-observer agreement on PET results was 88% (kappa = 0.74) in the RCA territory, 94% (kappa = 0.84) in the LAD territory and 94% (kappa = 0.85) in the LCX territory. Segmental PET measurements correctly identified 85% of the patients, resulting in a global sensitivity of 86%, a specificity of 84%, a positive predictive value (PPV) of 69% and a negative predictive value (NPV) of 93%. In vessel-based analyses, quantitative perfusion parameters had a sensitivity, specificity, PPV and NPV of 92%, 82%, 42% and 99%, respectively, for the detection of significant coronary stenoses in all major coronary arteries. The assessment of absolute myocardial perfusion parameters measured at a segment level lead to reliable and accurate identification of patients with significant coronary stenosis at ICA and/or CCTA.

Established and emerging cardiovascular magnetic resonance techniques for the assessment of stable coronary heart disease and acute coronary syndromes.

Coronary heart disease (CHD) is a leading cause of death and disability worldwide. International guidelines recommend cardiovascular magnetic resonance (CMR) as an investigative option in those presenting with chest pain to inform diagnosis, risk stratify and determine the need for revascularization. CMR offers a unique method to assess global and regional cardiac function, myocardial perfusion, myocardial viability, tissue characterisation and proximal coronary anatomy all within a single study. This results in high diagnostic accuracy for the detection of significant coronary stenoses and an established role in the management of both stable CHD and acute coronary syndromes (ACS). The growing evidence base for the prognostic value of CMR, emerging advances in acquisition techniques, improvements in hardware and the completion of current major multi-centre clinical CMR trials will further raise its prominence in international guidelines and routine cardiological practice. This article will focus on the rapidly evolving role of the multi-parametric CMR examination in the assessment of patients with stable and unstable CHD.

Das Herz beim Seniorensportler: Benefit und Risiken

Regular physical activity (PA) is a cornerstone of good health in the ageing population. Cardiorespiratory fitness is an important surrogate marker for survival. In primary cardiovascular disease prevention, PA is considered an effective mono­therapy with beneficial effects on the cardiovascular risk profile (e.g. lipid profile, blood pressure, diabetes mellitus, body composition) and endothelial function. In secondary prevention, PA is an addition to, rather than a replacement for evidence-based medication. There is growing evidence that high intensity interval training (HIIT) has superior effects on relevant clinical endpoints (cardiorespiratory fitness, cardiac remodeling, quality of life) compared to the established continuous moderate intensity training. Prevalence of coronary artery disease increases with age. Therefore the risk for exercise-induced sudden cardiac death should be taken into account in middle-aged/senior athletes. Determination of the cardiovascular risk profile and according lifestyle-modifications are crucial in the aging non-athlete population. While exercise testing is used for detection of significant coronary stenosis in the clinical setting, it does not reliably predict the risk of plaque rupture.

Cardiac computed tomography guided treatment strategy in patients with recent acute-onset chest pain: Results from the randomised, controlled trial: CArdiac cT in the treatment of acute CHest pain (CATCH)

ObjectivesIn patients admitted on suspicion of acute coronary syndrome, with normal electrocardiogram and troponines, we evaluated the clinical impact of a Coronary CT angiography (CCTA)-strategy on referral rate for invasive coronary angiography (ICA), detection of significant coronary stenoses (positive predictive value [PPV]) and subsequent revascularisations, as compared to a function-based strategy (standard care). Secondarily we assessed intermediate term clinical events. Methods and resultsWe randomised 600 patients to a CCTA-guided strategy (299 patients) or standard care (301 patients). In the CCTA-guided group referral for ICA required a coronary stenosis >70% or >50% in the left main, and for intermediate stenoses (50–70%), a stress test was used. A significant stenosis on ICA was defined as a stenosis ≥70% or reduced FFR ≤0.75 in intermediate stenoses (50–70%). Referral rate for ICA was 17% with CCTA vs. 12% with standard care (p=0.1). ICA confirmed significant coronary artery stenoses in 12% vs. 4% (p=0.001), and 10% vs. 4% were subsequently revascularised (p=0.005). PPV for the detection of significant stenoses was 71% with CCTA vs 36% with standard care (p=0.001). Clinical events (cardiac death, myocardial infarction, unstable angina pectoris, revascularisation and readmission for chest pain), during 120days of follow-up, were recorded in 8 patients (3%) in the CCTA-guided group vs. 15 patients (5%) in the standard care group (p=0.1). ConclusionIn patients with recent acute-onset chest pain, a CCTA-guided diagnostic strategy improves PPV for the detection of significant coronary stenoses, and increases the frequency of revascularisations, when compared to a conventional functional approach.

Non rate-controlled CT coronary angiography for the exclusion of obstructive coronary artery disease in the assessment of patients referred for transcatheter aortic valve implantation

Purpose: Optimal management of concomitant coronary artery disease (CAD) in patients undergoing transcatheter aortic valve implantation (TAVI) is contentious. This study aimed to assess the role of routine non rate-controlled CT coronary angiography (CTCA) in assessing CAD in patients referred for TAVI, thereby potentially precluding the need for invasive coronary angiography (ICA). CTCA in this cohort can be difficult due to the high burden of coronary calcium and the inability to perform standard pharmacological rate control. Methods: All patients underwent an ECG-gated 128-slice calcium score and CT angiogram to assess peripheral vasculature, aortic anatomy, aortic valve calcification and location of the coronary ostia. Coronary artery calcium scores (CACS) and CTCA images were scored by two independent, blinded observers and compared with ICA performed prior to TAVI. Significant coronary stenosis was defined as ≥70% and ICA was deemed the gold standard for true disease status. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated for CTCA at a patient level. Results: 70 consecutive patients referred for consideration of TAVI were studied: 40% male (n=28), mean age 78.9yrs (±7.91), 23% diabetic (n=16). Significant CAD was demonstrated in 30% of ICA studies (1 vessel disease (VD) 20% [n=14], 2VD 8.6% [n=6], 3VD 1.4% [n=1]). The sensitivity, specificity, PPV and NPV of CTCA for the detection of significant coronary stenoses were 57.9% (CI: 33.5% to 79.7%), 87.0% (CI: 75.1% to 94.6%), 61.1% (CI: 35.8% to 82.6%) and 85.4% (CI: 73.3% to 93.5%) respectively. The vast majority of false positive (5/6; 83%) and false negative (6/7; 86%) CTCAs were seen in patients in the highest quartile of CACS (>400). Conclusions: In patients undergoing CT assessment prior to TAVI, non rate-controlled CTCA shows poor sensitivity but good specificity and negative predictive value for the detection of significant CAD. A CAC score >400 may represent a threshold above which invasive angiography is mandated.

Combined CT angiography and SPECT myocardial perfusion imaging for the detection of functionally relevant coronary stenoses

The present study aimed to discuss and evaluate the diagnostic performances and incremental clinical values of combined computed tomography coronary angiography (CTCA) and single photon myocardial perfusion imaging (MPI) for the detection of functionally relevant coronary stenoses (FRCS). In total, 54patients underwent CTCA, MPI and coronary angiography (CAG) within 30days. The diagnostic performances of CTCA and combined CTCA plus MPI for the detection of significant coronary stenoses (≥50%) were calculated on the patient‑ or vessel‑based levels and included the indices of sensitivity (SN), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and accuracy (AC). On the patient‑based level, the SP, PPV, NPV and AC of CTCA alone or combined with MPI in the detection of FRCS were 90.9 and 90.9, 71.9 and 96.9, 69.0 and 95.2, 92.0 and 93.9 and 79.6 and 94.4%, respectively. On the vessel‑based level, the SN, SP, PPV, NPV and AC of CTCA alone or combined with MPI in the detection of FRCS were 90.3 and 90.3, 87.6 and 98.9, 54.9 and 93.3, 98.2 and 98.4 and 88.0 and 97.7%, respectively. The PPV, SP and AC of combined CTCA and MPI in the detection of FRCS were significantly improved compared with CTCA alone (all values, P<0.05). The diagnostic performance of combined CTCA and MPI in the detection of FRCS not only retains a high SN and NPV, but also markedly improves SP, PPV and AC, which should play an incremental and significant role in the decision‑making process for the revascularization therapy of coronary artery disease (CAD).

Accuracy of Two-Dimensional Speckle Tracking Echocardiography for the Detection of Significant Coronary Stenosis

BackgroundVisual assessment of wall motion abnormalities (WMA) by 2-dimensional echocardiography (2DE) is the most semi-quantitative method used to detect coronary artery disease (CAD), but it carries many limitations. Speckle tracking echocardiography (STE) overcomes these limitations and allows an objective quantification of myocardial deformation. The aim of the study to examine the accuracy of global and segmental longitudinal strain (LS) for the detection of CAD compared with visual assessment of WMA using coronary angiography as a golden standard.MethodsThe study enrolled 25 patients (mean age 51.0 ± 8.7, 64% are male) referred to coronary angiography with clinical suspicion of CAD. 2DE assessment of WMA and evaluation of LS using STE were performed using left ventricular 17-segments models. Significant CAD was defined as ≥ 50% stenosis in one or more major coronary arteries by angiography.ResultsPatients were classified into 2 groups: group I included 15 patients with significant CAD and group II included 10 patients with insignificant and/or absence of CAD. WM score was strongly correlated with the global LS in group I and II (R = 0.80, p < 0.0001 and R = 0.88, p < 0.0001 respectively). In all patients, 425 segments were analyzed. WMA was detected in 163 segments of 425 (38.3%) while abnormal LS was detected in 214 segments (50.3%). Compared with coronary angiography, the total sensitivity, specificity and accuracy for visual analysis and STE were (56%, 88.2%, and 60% vs. 68.6%, 77%, and 81.8% respectively).ConclusionSegmental LS is more accurate for the detection of ischemic myocardial segment corresponding to functionally relevant coronary anatomy than visual assessment of WM.

Association of Apolipoprotein B/Apolipoprotein A1 Ratio and Coronary Artery Stenosis and Plaques Detected by Multi-Detector Computed Tomography in Healthy Population

Despite the noninvasiveness and accuracy of multidetector computed tomography (MDCT), its use as a routine screening tool for occult coronary atherosclerosis is unclear. We investigated whether the ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1), an indicator of the balance between atherogenic and atheroprotective cholesterol transport could predict occult coronary atherosclerosis detected by MDCT. We collected the data of 1,401 subjects (877 men and 524 women) who participated in a routine health screening examination of Asan Medical Center. Significant coronary artery stenosis defined as > 50% stenosis was detected in 114 subjects (8.1%). An increase in apoB/A1 quartiles was associated with increased percentages of subjects with significant coronary stenosis and noncalcified plaques (NCAP). After adjustment for confounding variables, each 0.1 increase in serum apoB/A1 was significantly associated with increased odds ratios (ORs) for coronary stenosis and NCAP of 1.23 and 1.18, respectively. The optimal apoB/A1 ratio cut off value for MDCT detection of significant coronary stenosis was 0.58, which had a sensitivity of 70.2% and a specificity of 48.2% (area under the curve, 0.61; 95% CI, 0.58-0.63, P < 0.001). Our results indicate that apoB/A1 ratio is a good indicator of occult coronary atherosclerosis detected by coronary MDCT.

Computer-Aided Analysis of 64-Slice Coronary Computed Tomography Angiography: A Comparison with Manual Interpretation

Coronary computed tomography angiography (CCTA) is increasingly used for the assessment of coronary heart disease (CHD) in symptomatic patients. Software applications have recently been developed to facilitate efficient and accurate analysis of CCTA. This study aims to evaluate the clinical application of computer-aided diagnosis (CAD) software for the detection of significant coronary stenosis on CCTA in populations with low (8%), moderate (13%), and high (27%) CHD prevalence. A total of 341 consecutive patients underwent 64-slice CCTA at 3 clinical sites in the United States. CAD software performed automatic detection of significant coronary lesions (>50% stenosis). CAD results were then compared to the consensus manual interpretation of 2 imaging experts. Data analysis was conducted for each patient and segment. The CAD had 100% sensitivity per patient across all 3 clinical sites. Specificity in the low, moderate, and high CHD prevalence populations was 64%, 41%, and 38%, respectively. The negative predictive value at the 3 clinical sites was 100%. The positive predictive value was 22%, 21%, and 38% for the low, moderate, and high CHD prevalence populations, respectively. This study demonstrates the utility of CAD software in 3 distinct clinical settings. In a low-prevalence population, such as seen in the emergency department, CAD can be used as a Computer-Aided Simple Triage tool to assist in diagnostic delineation of acute chest pain. In a higher prevalence population, CAD software is useful as an adjunct for both the experienced and inexperienced reader.

Abstract 18978: Resting Pressure Gradient (iFG) Instantaneous Wave-free ratio (iFR) for Non-culprit Stenosis Evaluation in Patients with Acute Coronary Syndromes. Preliminary Data from the FORECAST Study

Background: The assessment of non-culprit stenoses is an important issue in ACS. Adenosine administration is currently required for functional evaluation of stenosis severity using the fractional flow reserve (FFR). An alternative adenosine-independent index of coronary stenosis, the instantaneous wave-free ratio (iFR), was recently introduced. Objective: Aim of the present study was to evaluate the trans-stenotic instantaneous wave-free pressure gradient (iFG), the instantaneous wave-free ratio (iFR) and the fractional flow reserve (FFR) in ACS patients. Methods: Intracoronary diastolic pressure was measured proximal and distal to the stenosis during the wave-free period with a pressure wire (Certus, St. Jude, USA) at baseline and upon iv adenosine administration (140 ug/kg/min). The data were acquired with a PowerLab (AD Instruments, USA) and analyzed with a LabChart 7. Results: A total of 71 stenoses were evaluated in the present study. iFR showed a correlation with FFR (r=0.61, p&lt;0.001), while a proportional error was documented with the Bland-Altman analysis. At multivariate analysis, the localization of the evaluated stenosis within the coronary tree influenced the correlation of iFR with FFR (p=0.03). ROC analysis showed a promising diagnostic efficiency for detection of significant coronary stenosis with iFR (AUC=0.936; p&lt;0.001) or iFG (AUC=0.944; p&lt;0.001). Conclusions: The instant wave-free ratio (iFR) and the resting distal-to-proximal pressure gradient measured during the wave-free period (iFG) showed a good diagnostic performance for the assessment of non-culprit lesions in ACS, representing a promising and adenosine-independent alternative to standard fractional flow reserve (FFR).

Hybrid SPECT/CT Imaging in the Evaluation of Coronary Stenosis: Role in Diabetic Patients.

Purpose. Our purpose was to combine the results of the MDCT (multidetector computed tomography) morphological data and the SPECT (single-photon emission computed tomography) data using hybrid imaging to overcome the limits of the MDCT in the evaluation of coronary stenosis in diabetic patients with large amount of calcium in the coronary arteries. Method and Materials. 120 diabetic patients underwent MDCT examination and SPECT examination. We evaluated 324 coronary arteries. After the examinations, we merged CT and SPECT images. Results. CT evaluation: 52 (32.8%) coronaries with stenosis ≥ 50%, 228 (70.4%) with stenosis < 50%, and 44 (13.6%) with a doubtful evaluation. SPECT evaluation: 80 (24.7%) areas with hypoperfusion, 232 (71.6%) with normal perfusion, and 12 (3.7%) with a doubtful evaluation. Of 324 coronary arteries and corresponding areas, the hybrid SPECT/CT evaluation showed 92 (28.4%) areas with hypoperfusion, and 232 (71.6%) with normal perfusion. Conclusion. Hybrid CT/SPECT imaging could be useful in the detection of significant coronary stenosis in patients with large amount of coronary calcifications.

Diagnostic Performance of Combined Noninvasive Anatomic and Functional Assessment With Dual-Source CT and Adenosine-Induced Stress Dual-Energy CT for Detection of Significant Coronary Stenosis

The purpose of our study was to prospectively evaluate the incremental diagnostic value of combined dual-source coronary CT angiography (CTA) and CT myocardial perfusion imaging (MPI) for the detection of significant coronary stenoses. Forty-five patients with known coronary artery disease detected by dual-source coronary CTA were investigated by adenosine-induced stress dual-source CTA and conventional coronary angiography. Analysis was performed in three steps: classification of coronary stenosis severity using dual-source coronary CTA, identification of myocardial perfusion defects using rest and stress CT MPI, and reclassification of coronary stenosis severity according to combined dual-source coronary CTA and CT MPI. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of dual-source coronary CTA before and after CT MPI were calculated on a per-vessel basis compared with conventional coronary angiography as the standard of reference. Dual-source coronary CTA revealed 87 significantly stenotic vessels in 45 patients. Conventional coronary angiography revealed significant stenoses in 73 vessels in 42 patients. CT MPI showed myocardial perfusion defects in 81 vessel territories in 43 patients. After the CT MPI analysis, dual-source coronary CTA identified significant stenoses in 77 coronary vessels in 42 patients. Sensitivity, specificity, PPV, and NPV of the dual-source coronary CTA on a per-vessel basis before CT MPI were 91.8%, 67.7%, 73.6%, and 87.5%, respectively, and after CT MPI were 93.2%, 85.5%, 88.3%, and 91.4%, respectively. The area under the receiver operating characteristic curve increased significantly from 0.798 to 0.893 (p = 0.004). Combined dual-source coronary CTA and CT MPI provides incremental diagnostic value compared with dual-source coronary CTA alone for the detection of significant coronary stenoses.

Coronary MR angiography using citrate‐coated very small superparamagnetic iron oxide particles as blood‐pool contrast agent: Initial experience in humans

To evaluate very small superparamagnetic iron oxide particles (VSOP-C184) as blood-pool contrast agent for coronary MR angiography (CMRA) in humans. Six healthy volunteers and 14 patients with suspected coronary artery disease underwent CMRA after administration of VSOP-C184 at the following doses: 20 μmol Fe/kg (4 patients), 40 μmol Fe/kg (5 patients), 45 μmol Fe/kg (6 healthy volunteers), and 60 μmol Fe/kg (5 patients). In healthy volunteers, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and vessel edge definition (VED) of contrast-enhanced CMRA were compared with non-contrast-enhanced CMRA. In patients, a per-segment intention-to-diagnose evaluation of contrast-enhanced CMRA for detection of significant coronary stenosis (≥50%) was performed. Three healthy volunteers (45 μmol Fe/kg VSOP-C184) and two patients (60 μmol Fe/kg VSOP-C184) had adverse events of mild or moderate intensity. VSOP-C184 significantly increased CNR (15.1 ± 4.6 versus 6.9 ± 1.9; P = 0.010), SNR (21.7 ± 5.3 versus 15.4 ± 1.6; P = 0.048), and VED (2.3 ± 0.6 versus 1.2 ± 0.2; P < 0.001) compared with non-contrast-enhanced CMRA. In patients, contrast-enhanced CMRA yielded sensitivity, specificity, and diagnostic accuracy for detection of significant coronary stenosis of 86.7%, 71.0%, 73.1%, respectively. CMRA using VSOP-C184 was feasible and yielded moderate diagnostic accuracy for detection of significant coronary stenosis within this proof-of-concept setting.

Incremental value of dual-energy CT to coronary CT angiography for the detection of significant coronary stenosis: comparison with quantitative coronary angiography and single photon emission computed tomography

To determine the value of dual-energy CT (DECT) and combined information of perfusion and angiography in diagnosing coronary artery disease (CAD), with single photon emission computed tomography (SPECT) and quantitative coronary angiography (QCA) as a reference standard. Thirty-four patients were enrolled in this study. DECT was used as a contrast-enhanced retrospectively ECG-gated scan protocol during the rest state and tubes were set at 140/100 kV. DECT angiography (DE-CTA) and DECT perfusion (DE-CTP) were calculated from two kV images. DE-CTP results were compared with SPECT and DE-CTA with QCA, respectively. The combined DE-CTP with DE-CTA data were compared to QCA in diagnosis of obstructive CAD (stenosis ≥ 50%). DECT showed diagnostic image quality in 31 patients. Using SPECT as a reference, DE-CTP had sensitivity of 68%, specificity of 93%, and sensitivity of 81%, and specificity of 92% for identifying any type of perfusion deficits on the segment- and territory-based analysis, respectively. Using QCA as a reference standard, DE-CTA showed sensitivity of 82%, specificity of 91% and accuracy of 86% for detecting ≥50% coronary stenosis on the vessel-based analysis, whereas the combination of DE-CTA and DE-CTP gave sensitivity of 90%, specificity of 86% and accuracy of 88% for detecting ≥50% coronary stenosis, respectively. Combination of DE-CTP and DE-CTA may improve diagnostic performance compared to CTA alone for the diagnosis of significant coronary stenosis.

CT comparison of visual and computerised quantification of coronary stenosis according to plaque composition

To compare the diagnostic performance of computerised quantification with visual assessment for the detection of significant coronary stenosis using MDCT, and to determine the impact of plaque composition on diagnostic procedure. We retrospectively evaluated 1564 coronary segments of 127 patients who underwent 64-slice MDCT and quantitative coronary angiography (QCA). The lesions were analysed with both methods of visual assessment and computerised quantification using an automatic vessel contour detection tool, and the results were compared with the QCA results. Plaques detected with MDCT were classified as calcified, mixed, and non-calcified according to plaque composition. The sensitivity and PPV of visual assessment (computerised quantification) were 95% (86%) and 76% (81%), respectively. Bland-Altman analysis demonstrated a mean difference of -5.2 ± 21.6% for all lesions, 2.2 ± 23.7 for calcified plaques, and -12.0 ± 17.2% for non-calcified plaques. The correlation coefficients and limits of agreement between CTA and QCA were 0.48 and ± 46.5% (0.74 and ± 33.7%) in the lesions with calcified plaques (non-calcified plaques). The computerised quantification decreases the sensitivity due to underestimation of non-calcified plaques compared with visual assessment, and had a poorer correlation and a larger limit of agreement in the lesions with calcified plaque compared with non-calcified plaques.