3D QCA Research Articles

P73 ANGIOGRAPHY–DERIVED INDEX OF MICROVASCULAR RESISTANCE (IMR–ANGIO) IN TAKOTSUBO SYNDROME

Abstract Introduction Coronary microvascular dysfunction (CMD) has been proposed as a key driver in the etiopathogenesis of Takotsubo syndrome (TTS), likely related to an “adrenergic storm” upon a susceptible microvascular circulation. The aim of our manuscript was to assess and quantify CMD in patients with TTS through non–invasive angio–derived index of microcirculation (IMRangio) and evaluate its correlation with clinical and instrumental presentation. Methods 41 consecutive TTS patients were retrospectively analyzed. Three different formulas for compute Non–Hyperemic IMRangio (NH–IMRangio) derived by 3D–Quantitative Coronary Angiography (3D–QCA) and Quantitative Flow Reserve (QFR) analysis were used according to each fluidodynamic mathematical expression as reported by respective authors. CMD was defined as an IMRangio ≥ 25. The correlation between NH–IMRangio and clinical presentation and the comparation between the three formulas were provided. Results Median age was 76 years, 85.7% were women and mean left ventricular ejection fraction (LVEF) at first echocardiogram was 41.2%. NH–IMRangio was higher in Left Anterior Descending artery (LAD) than Circumflex artery (CX) and Right Coronary artery (RCA) with either NH–IMRangio 1 (52.7 vs 35.3 vs 41.4), NH–IMRangio 2 (47.2 vs 31.8 vs 37.3) or NH–IMRangio 3 (52.7 vs 36.1 vs 41.8). All patients presented CMD with NH–IMR angio ≥ 25 in at least one territory with each formula. NH–IMRangio in LAD territory was significantly higher in patients presenting with LVEF impairment (≤40%) than in those with preserved ventricular global function (NH–IMRangio LAD 1: 59.3 vs 46.3, p. value=0.030; NH–IMRangio LAD 2: 52.9 vs 41.4, p–value=0.037; NH–IMRangio LAD 3: 59.2 vs 46.3, p–value=0–035). Association between NH–IMRangio computed in LAD and LVEF showed a moderate correlation (NH–IMRangio 1: r = –0,3485, Rho = 0,1214, p = 0,0256; NH–IMRangio 2: r = –0,3513; Rho = 0,1234, p = 0,0256; NH–IMRangio 3: r = –0,3326, Rho = 0,1106, p = 0,0336). Finally, Bland–Altman plot analysis showed good agreement between NH–IMRangio 1 and 3, while NH–IMRangio 2 showed a consistent bias of –5 units against both NH–IMRangio 1 and NH–IMRangio 2 with increasing difference at higher absolute values. Conclusion CMD, assessed with NH–IMRangio, is a common finding in TTS and it is inversely correlate with LVEF dysfunction. The available formulas for NH–IMRangio computation have a substantial superimposable diagnostic performance in assessing CMD.

TCTAP C-214 Where Anatomy Meets Physiology - Quantitative Flow Ratio (QFR) and Three-Dimensional Quantitative Coronary Analysis (3D QCA) Guided Percutaneous Coronary Intervention

TCTAP C-214 Where Anatomy Meets Physiology - Quantitative Flow Ratio (QFR) and Three-Dimensional Quantitative Coronary Analysis (3D QCA) Guided Percutaneous Coronary Intervention

100.07 Comparison of Stent Expansion Assessment by Three-Dimensional Quantitative Coronary Angiography Versus Optical Coherence Tomography

This study sought to determine whether stent expansion determined by Three-Dimensional Quantitative Coronary Angiography (3D QCA) is comparable to that of Optical Coherence Tomography (OCT). Stent expansion is the most important predictor of adverse outcomes after sent implantation. The high

Diagnostic Performance of QFR for the Evaluation of Intermediate Coronary Artery Stenosis Confirmed by Fractional Flow Reserve.

IntroductionQuantitative flow ratio (QFR) is a novel method enabling efficient computation of FFR from three-dimensional quantitative coronary angiography (3D QCA) and thrombolysis in myocardial infarction (TIMI) frame counting. We decided to perform a systematic review and quantitative meta-analysis of the literature to determine the correlation between the diagnosis of functionally significant stenosis obtained by QFR versus FFR and to determine the diagnostic accuracy of QFR for intermediate coronary artery stenosis.MethodsWe searched PubMed, Embase, and Web of Science for studies concerning the diagnostic performance of QFR. Our meta-analysis was performed using the DerSimonian and Laird random effects model to determine sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). The sROC was used to determine diagnostic test accuracy.ResultsNine studies consisting of 1175 vessels in 1047 patients were included in our study. The pooled sensitivity, specificity, LR+, LR-, and DOR for QFR were 0.89 (95% CI: 0.86-0.92), 0.88 (95% CI: 0.86-0.91), 6.86 (95% CI,: 5.22-9.02), 0.14 (95% CI: 0.10-0.21), and 53.05 (95% CI: 29.75-94.58), respectively. The area under the summary receiver operating characteristic (sROC) curve for QFR was 0.94.ConclusionQFR is a simple, useful, and noninvasive modality for diagnosis of functional significance of intermediate coronary artery stenosis.

Computational quantitative flow ratio to assess functional severity of coronary artery stenosis

BackgroundComputational quantitative flow ratio (QFR) based on 3-dimensional quantitative coronary angiography (3D QCA) analysis offers the opportunity to assess the significance of coronary artery disease (CAD) without using an invasive pressure wire or inducing hyperemia. This study aimed to evaluate the diagnostic performance of QFR compared to wire-based fractional flow reserve (FFR) and to validate the previously reported QFR cut-off value of >0.90 to safely rule out functionally significant CAD. MethodsQFR was retrospectively derived from standard-care coronary angiograms. Correlation and agreement of fixed-flow QFR (fQFR) and contrast-flow QFR (cQFR) models with invasive wire-based FFR was calculated. Diagnostic performance of QFR was evaluated at different QFR cut-off values defining significant CAD (FFR ≤ 0.80). Results101 vessels in 96 patients who underwent FFR were studied. Mean FFR was 0.87 ± 0.08 and 21 of 101 (21%) vessels had an FFR ≤ 0.80. Correlation of fQFR and cQFR with FFR was r = 0.71 (p < 0.001) and r = 0.70 (p < 0.001), respectively. Sensitivity and specificity were 57% and 93% for fQFR and 67% and 96% for cQFR at a QFR cut-off value >0.80 defining non-significant CAD, respectively. fQFR > 0.90 was present in 34 (34%) and cQFR > 0.90 in 39 (39%) vessels. For both QFR models, none of the vessels with QFR > 0.90 had an FFR ≤ 0.80. ConclusionsQFR appears to be a safe and effective gatekeeper to wire-based FFR when applying a QFR threshold of >0.90 to rule out significant CAD. Further prospective research is required to establish QFR in the real-life setting of functional CAD assessment in the catheterization laboratory.

Association of stent-induced changes in coronary geometry with late stent failure: Insights from three-dimensional quantitative coronary angiographic analysis.

The relationship between vessel angulation and large changes in vessel geometry after stent implantation and the occurrence of stent failure still remains unclear. We sought to investigate the association of the change in the coronary bending angle after stenting and the risk for late stent failure by three-dimensional quantitative coronary angiography (3D QCA). The bending angle in coronary lesions that presented with late stent failure and those without stent failure was computed during the cardiac cycle, before and after stenting using a recently developed 3D QCA software. A total of 40 lesions with stent failure (cases) were successfully matched to 47 lesions without stent failure (controls).The mean duration to follow-up coronary angiography was 1,011 days in cases and 1,109 days in the control group (P = 0.14). In stent failure, the systolic bending angle after stenting was smaller (14.45° [12.18, 17.68] versus 18.20° [14.00, 20.30], P = 0.01), while the stent-induced change in systolic bending angle was significantly larger (4.15° [1.13, 7.20] versus 1.80° [-1.90, 4.40], P = 0.004). Multivariable logistic regression analysis suggested that systolic bending angle after stenting (odds ratio: 0.88; 95% CI: 0.79-0.99; P = 0.03), and decrease in systolic bending angle after stenting (odds ratio: 1.13; 95% CI: 1.02-1.26; P = 0.03) were predictors of stent failure. Our study suggests that a change in the natural tortuous course of the coronaries by stent implantation with the decrease in coronary bending angle is a potentially major contributor in stent failure.

Accurate and reproducible reconstruction of coronary arteries and endothelial shear stress calculation using 3D OCT: Comparative study to 3D IVUS and 3D QCA

BackgroundGeometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter- and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. Methods-Results35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT. 3D OCT was validated against 3D IVUS and 3D QCA. The agreement in artery reconstruction among 3D OCT, 3D IVUS and 3D QCA was assessed in 3-mm-long subsegments using lumen morphometry and ESS parameters. The inter- and intra-observer agreement of 3D OCT, 3D IVUS and 3D QCA were assessed in a representative sample of 61 subsegments (n = 5 arteries). The data processing times for each reconstruction methodology were also calculated. There was a very high agreement between 3D OCT vs. 3D IVUS and 3D OCT vs. 3D QCA in terms of total reconstructed artery length and volume, as well as in terms of segmental morphometric and ESS metrics with mean differences close to zero and narrow limits of agreement (Bland–Altman analysis). 3D OCT exhibited excellent inter- and intra-observer agreement. The analysis time with 3D OCT was significantly lower compared to 3D IVUS. ConclusionsGeometrically-correct 3D OCT is a feasible, accurate and reproducible 3D reconstruction technique that can perform reliable ESS calculations in coronary arteries.

Aspiration of intact coronary bifurcation thrombus in ST-elevation myocardial infarction

We report a case of a 74-year-old female patient with acute chest pain who was admitted for primary percutaneous coronary angioplasty. The electrocardiogram indicated an acute ST-elevation myocardial infarction of the anterolateral wall. Coronary angiography showed a thrombus-containing lesion in the left anterior descending coronary artery with absence of a major diagonal branch (Fig. 1A; arrowhead). Administration of abciximab was not considered as there was some leakage of blood from the punctured, calcified femoral artery. An aspiration catheter was slowly advanced into the lesion, before vacuum-suction was initiated to manually remove thrombus. After careful retrieval, we found at its tip an intact Y-shaped thrombus (Fig. 1D) that resembled the shape of the bifurcation. After thrombus removal, blood flow was fully restored in the diagonal branch (Fig. 1B, arrowhead; Fig. 1E, 3D reconstruction by dedicated 3D QCA software [1] (Medis, Leiden, The Netherlands)). Following stent implantation of two drug-eluting coronary stents (Fig. 1C), the in-hospital course of our patient was uneventful, and the patient was discharged after 5 days. This case with a unique transcatheter removal of an intact coronary bifurcation thrombus nicely illustrates the pathophysiological principle of thrombus propagation from a fissured or ruptured plaque into both subordinate branches of a bifurcation

ST elevation acute myocardial infarction accelerates progression of non-culprit coronary lesion atherosclerosis

Objectives: The previously study found, using a mouse model, that acute myocardial infarction (AMI) accelerated atherosclerosis and increased inflammation in atherosclerotic plaques at a distance. The present study assessed whether ST elevation myocardial infarction (STEMI) accelerates the progression of non-culprit coronary lesion (NCCL) in patients who underwent coronary percutaneous coronary interventions (PCI) on initial admission. Methods: The study group comprised 351 Chinese patients with coronary artery disease (CAD) who underwent successful PCI with drug-eluting stents and follow-up (mean interval, (12.7±5.6)months) coronary angiography. We assessed the progression of non-culprit coronary lesion by using three-dimensional quantitative coronary angiography (3D QCA). The patients were classified into two groups according to whether the progression existed or not. Results: The study included 351 patients. The median age was 58.5 years, 18.8% were women, and 32.8% had diabetes mellitus. Mean follow-up between coronary angiographies was 12.7 months. Of 351 patients, 104 (29.6%) had rapid progression of NCCL, 133 (37.9%) were STEMI. Patients with progression were more often males (89.4% vs. 77.7%, respectively; p = 0.01). The STEMI conferred high risk of the progression of NCCL (OR 7.86, 95% CI 4.695-13.158, P < 0.001) and the association remained significantly after adjustment for age, sex, BMI, serum lipids, fasting blood glucose, smoking, drinking, hypertension and diabetes mellitus by multivariate logistic regression analysis (adjusted OR 9.21, 95% CI, 4.98 to 17.02; P<0.001). The peak monocyte count (p=0.018) and peak levels of CRP (p=0.001) were significantly higher in progression group than in non-progression group. The absolute change of high-density lipoprotein cholesterol (HDL-C) in rapid progression was significantly greater than non-progression of NCCL (p=0.025). At the follow-up CAG, all characteristics of NCCL in STEMI was significantly greater than non-STEMI group (p<0.001). The absolute change of all characteristics of NCCL in STEMI was significantly greater than non-STEMI group (p<0.001). Conclusions: The STEMI was an independent clinical predictor and accelerated the progression of NCCL. The circulating monocytes and CRP play an important role in the progression of NCCL and that the peak monocyte count and CRP during hospitalization might be a predictor of plaque progression.

Anatomic features of the left main coronary artery and factors associated with its bifurcation angle: A 3‐dimensional quantitative coronary angiographic study

To assess the anatomic characteristics of the left main coronary artery (LM), and the relation between anatomic and clinical factors and the LM bifurcation angle (BA) using a novel, three dimensional quantitative coronary angiography (3D QCA) software. Percutaneous intervention of the LM is a therapeutic option in selected patients with coronary artery disease (CAD). The anatomic features of the LM and its BA are determinants of procedural success and clinical outcome. However, those features and the factors that may affect the LM BA have not been fully described. The LM anatomy was evaluated from angiograms of 203 patients (age = 66 ± 11 years, 31% female) with and without LM CAD using 3D QCA analysis (IC-PRO, Paieon, Israel). LM size as well as the proximal BA (between LM and LCX) and the distal BA (between left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX)) were measured in end-diastole. Angiographic and clinical findings were also recorded. 133/203 patients (65%) had no LM CAD. 3D QCA analysis demonstrated significant variability in the anatomy of the normal LM, including the LM branch vessels (LAD, LCX) diameter, and the LM BA. Among the 70 patients with LM CAD, 44 had distal LM disease. Importantly, patients with distal LM CAD had narrower proximal BA and a wider distal BA. Multivariate analysis (adjusted for clinical and anatomic variables) identified female sex (P = 0.02), trifurcation anatomy (P = 0.009), age > 75 years (P = 0.0009), and LM length > 12 mm (P = 0.001) as independent associates of the proximal BA. Independent associates of the distal BA were: trifurcation anatomy (P = 0.001), LM length > 12 mm (P < 0.0001), age > 75 years (P = 0.004), and a history of coronary bypass surgery (P = 0.04). The current study demonstrates significant variability in the anatomy of the LM. The LM BA differs between patients with and without distal LM CAD, and both anatomic and clinical factors may affect the LM BA. Our findings also emphasize the possible usefulness of 3D QCA in the assessment of the LM.

Porównanie trójwymiarowej i dwuwymiarowej analizy ilościowej tętnic wieńcowych w odniesieniu do pomiaru długości segmentów wieńcowych u pacjentów poddawanych diagnostycznej koronarografii

Aim: To determine if three-dimensional quantitative coronary angiographic analysis (3D QCA) provides an advantage over twodimensional (2D QCA) by increasing accuracy and precision of length measurements through compensating for foreshortening inherent to 2D images. Material and methods: A total of 800 inter-marker length measurements were performed (8 per wire, 5-40 mm) with novel 3D software and standard 2D software and compared with the true lengths of the inter-marker distances on the wire in coronary vessels of 21 patients recruited. Results: 2D QCA generally underestimated true length in comparison to 3D, and the discrepancy increased with absolute length. In contrast, 3D QCA showed a minimal difference from true length over the examined range of lengths. Conclusions: 3D QCA minimizes errors in length measurements associated with foreshortening, shows minimal difference from true length, and performs significantly better in comparison to 2D QCA. The advantage of 3D QCA is more pronounced at longer lengths.

In vivo assessment of bifurcation optimal viewing angles and bifurcation angles by three-dimensional (3D) quantitative coronary angiography

Evaluation and stenting of coronary bifurcation lesions may benefit from optimal angiographic views. The anatomy-defined bifurcation optimal viewing angle (ABOVA) is characterized by having an orthogonal view of the bifurcation, such that overlap and foreshortening at the ostium are minimized. However, due to the mechanical constraints of the X-ray systems, certain deep angles cannot be reached by the C-arm. Therefore, second best or, so-called obtainable bifurcation optimal viewing angle (OBOVA) has to be used as an alternative. This study assessed the distributions of ABOVA and OBOVA using 3D quantitative coronary angiography in a typical patient population. In addition, the bifurcation angles in four main coronary bifurcations were assessed and compared. Patients with obstructive coronary bifurcation disease were included in this multicenter registry. A novel and validated 3D QCA software package was applied to reconstruct the bifurcations and to calculate the bifurcation angles in 3D. A list of optimal viewing angle candidates including ABOVA was also automatically proposed by the software. In a next step, the operator selected the best viewing angle as OBOVA, while applying a novel overlap prediction approach to assure no overlap between the target bifurcation and other major coronary arteries. A total of 194 bifurcations from 181 patients were assessed. The ABOVA could not be reached in 56.7% of the cases; being 40 (81.6%), 40 (78.4%), 9 (17.6%), and 21 (48.8%) cases for LM/LAD/LCx, LAD/Diagonal, LCx/OM, and PDA/PLA, respectively. Both ABOVA and OBOVA distributed sparsely with large ranges of variance: LM/LAD/LCx, 5 ± 33 RAO, 47 ± 35 Caudal versus 4 ± 39 LAO, 35 ± 16 Caudal; LAD/Diagonal, 4 ± 38 RAO, 50 ± 14 Cranial versus 14 ± 28 LAO, 33 ± 5 Cranial; LCx/OM, 21 ± 32 LAO, 27 ± 17 Caudal versus 18 ± 31 LAO, 25 ± 13 Caudal; PDA/PLA, 34 ± 21 LAO, 36 ± 21 Cranial versus 28 ± 25 LAO, 29 ± 15 Cranial. LM/LAD/LCx had the smallest proximal bifurcation angle (128° ± 24°) and the largest distal bifurcation angle (80° ± 21°), as compared with LAD/Diagonal (151° ± 13º and 48° ± 16º), LCx/OM (146° ± 18º and 57° ± 16°), and PDA/PLA (145° ± 19° and 59° ± 17°). In conclusion, large variabilities in optimal viewing angles existed for all main coronary bifurcations. The anatomy-defined bifurcation optimal viewing angle could not be reached in vivo in roughly half of the cases due to the mechanical constraints of the current X-ray systems. Obtainable bifurcation optimal viewing angle should be provided as an alternative or second best. The bifurcation angles in the left main bifurcation demonstrated the largest variabilities.

A novel three‐dimensional quantitative coronary angiography system: In‐vivo comparison with intravascular ultrasound for assessing arterial segment length

Accurate on-line assessments of vessel dimensions are of utmost importance for selecting the appropriate stent size in coronary interventions. Recently a new three-dimensional quantitative coronary angiography (3D QCA) analytical software package was developed to accurately assess the vessel dimensions for the planning and guidance of such coronary interventions. This study aimed to validate the 3D QCA software package for assessing arterial segment length by comparing with intravascular ultrasound (IVUS). In addition, the difference in the two measurements from 3D QCA and IVUS for curved segments was studied. A retrospective study including 20 patients undergoing both coronary angiography and IVUS examinations of the left coronary artery was set up for the validation. The same vessel segments of interest between proximal and distal markers were identified and measured on both angiographic and IVUS images, by the 3D QCA software and by a quantitative IVUS software package, respectively. In addition, the curvature of each of the segments of interest was assessed and the correlation between the accumulated curvature of the segment and the difference in segment lengths measured from the two imaging modalities was analyzed. 37 vessel segments of interest were identified from both angiographic and IVUS images. The 3D QCA segment length was slightly longer than the IVUS segment length (15.42 +/- 6.02 mm vs. 15.12 +/- 5.81 mm, P = 0.040). The linear correlation of the two measurements was: 3D QCA Length = -0.09 + 1.03 x IVUS Length (r(2) = 0.98, P < 0.001). Bland-Altman plot showed that the difference in the two measurements was not correlated with the average of the two measurements (P = 0.141), but with the accumulated curvature of the segment (P = 0.015). After refining the difference by the correlation, the average difference of the two measurements decreased from 0.30 +/- 0.86 mm (P = 0.040) to 0.00 +/- 0.78 mm (P = 0.977). The 3D QCA software package can accurately assess the actual arterial segment length. The difference in segment lengths measured from 3D QCA and IVUS was correlated with the accumulated curvature of the segment.

Assessment of obstruction length and optimal viewing angle from biplane X-ray angiograms

Three-dimensional quantitative coronary angiography (3D QCA) has been encouraged by the increasing need to better assess vessel dimensions and geometry for interventional purposes. A novel 3D QCA system based on biplane X-ray angiograms is presented in this paper. By correcting for the isocenter offset and by improving the epipolar constraint for corresponding two angiographic projections, accurate and robust reconstruction of the vessel centerline is achieved and the reproducibility of its applications, e.g., the assessments of obstruction length and optimal viewing angle, is guaranteed. The accuracy and variability in assessing the obstruction length and optimal bifurcation viewing angle were investigated by using phantom experiments. The segment length assessed by 3D QCA correlated well with the true wire segment length (r 2 = 0.999) and the accuracy and precision were 0.04 ± 0.25 mm (P < 0.01). 3D QCA slightly underestimated the rotation angle (difference: −1.5° ± 3.6°, P < 0.01), while no significant difference was observed for the angulation angle (difference: −0.2° ± 2.4°, P = 0.54). In conclusion, the new 3D QCA approach allows highly accurate and precise assessments of obstruction length and optimal viewing angle from X-ray angiography.

Clinical assessment of a new real time 3D quantitative coronary angiography system: Evaluation in stented vessel segments

Foreshortening is a recognized problem that is present in angiography and results from views that are not perpendicular to coronary lesions. This limits visual coronary analysis as well as 2D quantitative coronary angiography systems (QCA). The CardiOp-B System is a 3D image acquisition and processing software system designed as an add-on to conventional X-ray angiography system. CardiOp-B's features include real time and off line analysis with comprehensive 3D reconstruction integrating all of the available information of two 2D vessel angiographies into one 3D image. It was the aim of the study to analyze the accuracy of this new 3D QCA system. 3D QCA was performed in 50 patients (age 64 +/- 10.9; 84% male; LV-EF 63 +/- 16%) measuring 61 stents during high-pressure inflation (diameter: 2.25-4 mm; length: 8-32 mm). The obtained values (proximal and distal stent diameter, stent length) were correlated with the predefined size of the stents at the used inflation pressure. The linear correlation for the proximal stent diameter was Stent(prox)= 0.03 + 0.93 x real stent size (r(2) = 0.85). The linear correlation for the distal stent diameter was Stent(distal)= -0.03 + 0.89 x real stent size (r(2) = 0.81). The linear correlation for the stent length was Stent(length)= -0.61 + 1.02 x real stent length (r(2) = 0.98). The CardiOp-B System(R) is a new 3D QCA system with a high linear correlation between the real vessel size and the obtained vessel dimension. It provides real time or off line accurate and comprehensive diagnostic information to the interventional cardiologist without changing the basic coronary angiography procedure.