The diagnostic performance of coronary artery angiography with 64-MSCT and post 64-MSCT: systematic review and meta-analysis

Feasibility and Comparison of Resting Full-Cycle Ratio and Computed Tomography Fractional Flow Reserve in Patients with Severe Aortic Valve Stenosis

Background: Computed tomography derived Fractional Flow Reserve (CT-FFR) has been shown to decrease the referral rate for invasive coronary angiography (ICA). The purpose of the study was to evaluate the diagnostic performance of CT-FFR compared to hyperemia-free index Resting Full-cycle Ratio (RFR) in patients with relevant aortic stenosis (AS) and intermediate coronary stenosis. Methods: 41 patients with 46 coronary lesions underwent ICA with quantitative coronary angiography (QCA), pressure wire assessment and routine pre-transcatheter aortic valve replacement (TAVR) computed tomography (CT). CT-FFR analysis was performed using prototype on-site software. Results: RFR showed a significant correlation with CT-FFR (Pearson’s correlation, r = 0.632, p < 0.001). On a per-lesion basis, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 82.6% (95% CI 68.6−92.2), 69.6% (95% CI 47.1−86.8), 95.7% (95% CI  78.1−99.9), 94.1% (95% CI 69.8−99.1), and 75.9% (95% CI 62.7−85.4), respectively. The optimal cutoff value of the CT-FFR for RFR ≤ 0.89 prediction was 0.815. The area under the receiver curve showed a larger area under the curve for CT-FFR (0.87; 95% CI 0.75−0.98) compared with CTA stenosis of ≥50% (0.54, 95% CI 0.38−0.71), CTA ≥ 70% (0.72, 95% CI 0.57−0.87) and QCA ≥ 50% (0.67, 95% CI 0.52−0.83). Conclusions: CT-FFR assessed by routine pre-TAVR CT is safe and feasible and shows a significant correlation with RFR in patients with AS. CT-FFR is superior to QCA ≥ 50%, CT ≥ 50% and CT ≥ 70% in assessing the hemodynamic relevance of intermediate coronary lesions. Thus, CT-FFR has the potential to guide revascularization in patients with AS.

CTA-Based Non-invasive Estimation of Pressure Gradients Across a CoA: a Validation Against Cardiac Catheterisation

Non-invasive estimation of pressure gradients across a coarctation of the aorta (CoA) can reduce the need for diagnostic cardiac catheterisation. We aimed to validate two novel computational strategies-target-value approaching (TVA) and target-value fixing (TVF)-together with unrefined Doppler estimates, and to compare their diagnostic performance in identifying critical pressure drops for 40 patients. Compared to catheterisation, no statistically significant difference was demonstrated with TVA (P = 0.086), in contrast to TVF (P = 0.005) and unrefined Doppler echocardiography (P < 0.001). TVA manifested the strongest correlation with catheterisation (r = 0.93), compared to TVF (r = 0.83) and echocardiography (r = 0.67) (all P < 0.001). In discriminating pressure gradients greater than 20 mmHg, TVA, TVF, and echocardiography had respective sensitivities of 0.92, 0.88, and 0.80; specificities of 0.93, 0.80, and 0.73; and AUCs of 0.96, 0.89, and 0.80. The TVA strategy may serve as an effective and easily implemented approach to be used in clinical management of patients with CoA. Graphical Abstract Central illustration. Pressure gradients estimated using Doppler echocardiography and two novel computational strategies (TVA and TVF) were compared with cardiac catheterisation for 40 patients. TVA and TVF utilised the CTA images to obtain the CoA anatomy and Doppler echocardiography velocimetry to obtain velocity data for the assignment of CFD boundary conditions.

Umbrella review and multivariate meta-analysis of diagnostic test accuracy studies on hybrid non-invasive imaging for coronary artery disease

BACKGROUND

The diagnosis of coronary artery disease (CAD) remains challenging. It is uncertain whether hybrid imaging can improve diagnostic accuracy for CAD.

METHODS

This is a systematic review and multivariate meta-analysis. We searched PubMed and The Cochrane Library for recent (≥ 2010) systematic reviews of diagnostic test accuracy studies on non-invasive imaging for CAD. Study-level data were extracted from them, and pooled with pairwise and multivariate meta-analytic methods, using invasive coronary angiography (ICA) or invasive fractional flow reserve (FFR) as reference standards, focusing on sensitivity and specificity.

RESULTS

Details from 661 original studies (71,823 patients) were pooled. Pairwise meta-analysis using ICA as reference showed that anatomic imaging was associated with the best diagnostic accuracy (sensitivity = 0.95 [95% confidence interval 0.94-0.96], specificity = 0.83 [0.81-0.85]), whereas using FFR as reference identified hybrid imaging as the best test (sensitivity = 0.87 [0.83-0.90], specificity = 0.82 [0.76-0.87]). Multivariate meta-analysis confirmed the superiority of anatomic imaging using ICA as reference (sensitivity = 0.96, specificity = 0.83), and hybrid imaging using FFR as reference (sensitivity = 0.88 [0.86-0.91], specificity = 0.82 [0.77-0.87]).

CONCLUSIONS

Non-invasive hybrid imaging tests appear superior to anatomic or functional only tests to diagnose ischemia-provoking coronary lesions, whereas anatomic imaging is best to diagnose and/or rule out angiographically significant CAD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO Registry Number CRD42018088528.

Predicting the presence of coronary artery disease by transesophageal echocardiography

Background

The accuracy of ultrasound signs as predictors for the presence of coronary artery disease (CAD) has been evaluated extensively in the 1990s and 2000s. Imaging quality has improved tremendously over the last decades.

Hypothesis

High-end ultrasound systems allow for accurate prediction of the presence or absence of CAD.

Methods

All patients who underwent a transesophageal echocardiography examination (TEE) between 2007 and 2016 and who had coronary angiography within 24 months before or after the TEE were retrospectively evaluated.

Results

A total of 242 patients fulfilled the inclusion criteria, 60% were male. Mean age was 70 years (SD ± 13 years). In multivariate regression analysis, plaque in the ascending aorta (odds ratio [OR] 2.51, 95% confidence interval [CI] 1.18–5.32, p = 0.017), plaque in at least one of the thoracic aortic segments (OR 2.07, 95% CI 1.02–4.22, p = 0.045), and the presence of mitral annular calcification (MAC, OR 1.84, 95% CI 1.01–3.36, p = 0.046) were predictors of significant CAD. The isolated finding of aortic stenosis (AS) (OR 2.53, 95%CI 1.23–5.21, p = 0.012) was a significant predictor for the absence of normal coronary arteries.

Conclusion

With an negative predictive value (NPV) of 80%, the absence of MAC, AS, and aortic plaque makes the presence of significant CAD unlikely. If at least mild AS is present, normal coronary arteries are improbable.

Coronary CT angiography in acute chest pain

Coronary computed tomographic angiography has become a reliable diagnostic tool in the evaluation of patients with chest pain. Studies have shown this modality to be accurate and safe when compared with conventional methods of assessing patients with chest pain. We review the recent developments with coronary computed tomographic angiography and devote particular attention toward its application to triage patients in the emergency department.

Non-contrast MR angiography using three-dimensional balanced steady-state free-precession imaging for evaluation of stenosis in the celiac trunk and superior mesenteric artery: a preliminary comparative study with computed tomography angiography

OBJECTIVE

Although non-contrast MR angiography (NC-MRA) is well established for the evaluation of renal artery stenosis, its usefulness in the evaluation of other abdominal aortic branches remains to be studied. This study aimed at evaluating the image quality and diagnostic accuracy of NC-MRA using a three-dimensional balanced steady-state free-precession sequence in identifying stenosis in the celiac trunk (CTR) and superior mesenteric artery (SMA) as compared with CT angiography (CTA) as the reference standard.

METHODS

41 patients underwent both NC-MRA and CTA of the abdominal aorta. Two radiologists analyzed the quality of the images (diagnostic vs non-diagnostic) and the performance (accuracy, sensitivity and specificity) of NC-MRA for the identification of arterial stenosis. Kappa tests were used to determine the interobserver agreement and the intermethod agreement between NC-MRA and CTA.

RESULTS

NC-MRA provided diagnostic quality images of the CTR and SMA in 87.8% and 90.2% of cases, respectively, with high interobserver agreement (kappa 0.95 and 0.80, respectively). For stenosis assessment, NC-MRA had a sensitivity of 100%, a positive-predictive value of 50% and a negative-predictive value of 100% for both segments, with accuracies of 88.8% for the CTR and 94.5% for the SMA.

CONCLUSION

NC-MRA is an accurate method for detecting stenosis in the CTR and SMA. Advances in knowledge: Data from this study suggest that MR angiography with balanced steady-state free-precession sequence is a viable non-contrast alternative for stenosis evaluation of these branches in patients for whom a contrast-enhanced examination is contraindicated.

Comparison of coronary computed tomography angiography image quality with high- and low-concentration contrast agents (CONCENTRATE): study protocol for a randomized controlled trial

BACKGROUND

With the development of computed tomography (CT) technology, coronary CT angiography can be acquired with low doses of radiation and contrast agent without a loss of diagnostic performance. The primary objective of the CONCENTRATE study is to prove the noninferiority of the enhancement effect of low-concentration contrast agents compared to a high-concentration contrast agent of the coronary artery and myocardium with coronary CT angiography.

METHODS/DESIGN

The CONCENTRATE study is a prospective, multicenter, noninferiority, randomized trial evaluating the enhancement effect of low-concentration contrast agents (270 and 320 mg iodine/ml) compared with a high-concentration contrast agent (370 mg iodine/ml) in the coronary artery and myocardium of coronary artery CT angiography. The primary efficacy measurement is the enhancement of coronary arteries as measured in Hounsfield units. The target population comprises 318 patients with suspected coronary artery disease who have been referred for clinically indicated nonemergent coronary CT angiography. Eligible participants are randomized for three different concentrations of the contrast agent in a 1:1:1 allocation ratio to one of three arms. The CONCENTRATE trial is a double-blind study, where the subjects and the outcome assessor are blinded to the concentration of the contrast agent used for coronary the CT angiography. Eight clinical sites in Korea are participating in this trial.

DISCUSSION

The CONCENTRATE study will determine whether low-concentration contrast agents are able to provide diagnostic image quality in coronary CT angiography.

TRIAL REGISTRATION

NCT02549794 . Registered on 14 September 2015.

Current and future trends in multimodality imaging of coronary artery disease

Nowadays, there is a wide array of imaging studies available for the evaluation of coronary artery disease, each with its particular indications and strengths. Cardiac single photon emission tomography is mostly used to evaluate myocardial perfusion, having experienced recent marked improvements in image acquisition. Cardiac PET has its main utility in perfusion imaging, atherosclerosis and endothelial function evaluation, and viability assessment. Cardiovascular computed tomography has long been used as a reference test for non-invasive evaluation of coronary lesions and anatomic characterization. Cardiovascular magnetic resonance is currently the reference standard for non-invasive ventricular function evaluation and myocardial scarring delineation. These specific strengths have been enhanced with the advent of hybrid equipment, offering a true integration of different imaging modalities into a single, simultaneous and comprehensive study.