The effect of coronary bifurcation and haemodynamics in prediction of atherosclerotic plaque development: a serial computed tomographic coronary angiographic study.

AIMS: The aim of this study was to examine the effect of the daughter branches on the haemodynamics and the potential prediction of atherosclerotic plaque development as well as the best flow division model for accurate blood flow modelling. METHODS AND RESULTS: We analysed computed tomography coronary angiography retrospective data portraying 17 coronary artery bifurcations in 15 patients recruited into the PROSPECT MSCT study. Baseline and three-year follow-up imaging data were used to reconstruct coronary artery anatomy. In the baseline models blood flow simulations were performed using three flow division approaches: stress-free, Murray's law and Doriot's fit. Blood flow simulation was also performed omitting the daughter branch. The association between ESS estimated in models that incorporated the daughter branches and lumen reduction was higher than the cases where the side branch was omitted. Murray's law provides the most accurate results when comparing the different flow division models. More specifically, low ESS is a predictor of significant lumen reduction (p=0.007), plaque burden increase (p=0.0006) and necrotic core change (p=0.025). CONCLUSIONS: The ESS distribution in coronary models including the daughter branches and based on the calculations implementing Murray's law allows more accurate prediction of atherosclerotic evolution than ESS estimated in models including only the main vessel.

Prediction of atherosclerotic disease progression using LDL transport modelling: a serial computed tomographic coronary angiographic study.

AIM: To investigate the efficacy of low-density lipoprotein (LDL) transport simulation in reconstructed arteries derived from computed tomography coronary angiography (CTCA) to predict coronary segments that are prone to progress. METHODS AND RESULTS: Thirty-two patients admitted with an acute coronary event who underwent 64-slice CTCA after percutaneous coronary intervention and at 3-year follow-up were included in the analysis. The CTCA data were used to reconstruct the coronary anatomy of the untreated vessels at baseline and follow-up, and LDL transport simulation was performed in the baseline models. The computed endothelial shear stress (ESS), LDL concentration, and CTCA-derived plaque characteristics were used to identify predictors of substantial disease progression (defined as an increase in the plaque burden at follow-up higher than two standard deviations of the intra-observer variability of the expert who performed the analysis). Fifty-eight vessels were analysed. High LDL concentration [odds ratio (OR): 2.16; 95% confidence interval (CI): 1.64-2.84; P = 0.0054], plaque burden (OR: 1.40; 95% CI: 1.13-1.72; P = 0.0017), and plaque area (OR: 3.46; 95% CI: 2.20-5.44; P≤ 0.0001) were independent predictors of a substantial disease progression at follow-up. The ESS appears as a predictor of disease progression in univariate analysis but was not an independent predictor when the LDL concentration was entered into the multivariate model. The accuracy of the model that included the LDL concentration was higher than the accuracy of the model that included the ESS (65.1 vs. 62.5%). CONCLUSIONS: LDL transport modelling appears a better predictor of atherosclerotic disease progression than the ESS, and combined with the atheroma characteristics provided by CTCA is able to detect with a moderate accuracy segments that will exhibit a significant plaque burden increase at mid-term follow-up.

Differences between the left main and other bifurcations.

The left main is the largest bifurcation of the coronary tree and is, therefore, easier to access. Nevertheless, the risks of untoward consequences associated with the loss of the side branch are much higher. Although the usual technical strategies implemented in coronary bifurcations can generally be applied to left main lesions, several inherent characteristics (the ostial position of the main branch, the size of the side branch, the amount of calcification, the angle which is often in a T shape, the use of stents of variable suitability, the crucial role of POT) need to be taken into account in order to achieve optimal acute and long-term results.

The need for dedicated bifurcation quantitative coronary angiography (QCA) software algorithms to evaluate bifurcation lesions.

Single-vessel quantitative coronary angiography (QCA) software is inaccurate when used in bifurcation lesions due to the specific anatomical characteristics of bifurcations, including the natural step-down in diameters after every bifurcation. Dedicated bifurcation QCA software has been developed to overcome the limitations of single-vessel QCA in bifurcations. A phantom validation study has shown the superior accuracy of these bifurcation QCA algorithms compared to the single-vessel QCA software. These QCA software algorithms are currently highly recommended to assess bifurcation lesions.

Comparison between two- and three-dimensional quantitative coronary angiography bifurcation analyses for the assessment of bifurcation lesions: A subanalysis of the TRYTON pivotal IDE coronary bifurcation trial.

BACKGROUND: Three-dimensional (3D) quantitative coronary angiography (QCA) provides more accurate measurements by minimizing inherent limitations of two-dimensional (2D) QCA. The aim of this study was to compare the measurements between 2D and 3D QCA analyses in bifurcation lesions. METHODS AND RESULTS: A total of 114 cases with non-left main bifurcation lesions in the TRYTON pivotal IDE Coronary Bifurcation Trial (ClinicalTrials.gov: NCT01258972) were analyzed using a validated bifurcation QCA software (CAAS 5.10, Pie Medical Imaging, Maastricht, the Netherlands). All cases were analyzed in matched projections between pre- and post-procedure. The 2D analysis was performed using one of two angiographic images used for 3D reconstruction showing a larger distal bifurcation angle. In the treated segments (stent and balloon), there were no differences in minimal luminal diameter (MLD) between 2D and 3D, while diameter stenosis (DS) was significantly higher in 2D compared to 3D both pre-procedure and post-procedure (53.9% for 2D vs. 52.1% for 3D pre-procedure, P < 0.01; 23.2% for 2D vs. 20.9% for 3D post-procedure, P = 0.01). In the sub-segment level analysis, lengths of proximal main branch, distal main branch, and side branch were consistently shorter in 2D compared to 3D both pre-procedure and post-procedure. Using 3D QCA, the anatomic location of the smallest MLD or the highest DS was relocated to a different bifurcation sub-segment in a considerable proportion of the patients compared to when 2D-QCA was used (kappa values: 0.50 for MLD, 0.55 for DS). CONCLUSIONS: Our data showed differences in addressing anatomical severity and location of coronary bifurcation lesions between in vivo 2D and 3D QCA analyses. More studies are needed to investigate potential clinical benefits in using 3D approach over 2D QCA for the assessment of bifurcation lesions.

Inter-core lab variability in analyzing quantitative coronary angiography for bifurcation lesions: a post-hoc analysis of a randomized trial.

OBJECTIVES: This study sought to evaluate inter-core lab variability in quantitative coronary angiography (QCA) analysis of bifurcation lesions. BACKGROUND: QCA of bifurcation lesions is challenging. To date there are no data available on the inter-core lab variability of bifurcation QCA analysis. METHODS: The randomized Tryton IDE (Tryton Pivotal IDE Coronary Bifurcation Trial) compared the Tryton Side Branch Stent (Tryton Medical, Durham, North Carolina) with balloon angioplasty as side branch treatment. QCA was performed in an angiographic subcohort (n = 326) at 9-month follow-up. Inter-core lab variability of QCA analysis between the Cardiovascular Research Foundation and the Cardialysis core labs was evaluated before and after alignment of the used QCA methodology using angiographic data derived from this angiographic follow-up cohort. RESULTS: In the original analysis, before alignment of QCA methodology, the mean difference between the core labs (bias) was large for all QCA parameters with wide 95% limits of agreement (1.96 × SD of the bias), indicating marked variability. The bias of the key angiographic endpoint of the Tryton trial, in-segment percentage diameter stenosis (%DS) of the side branch, was 5.5% (95% limits of agreement: -26.7% to 37.8%). After reanalysis, the bias of the in-segment %DS of the side branch reduced to 1.8% (95% limits of agreement: -16.7% to 20.4%). Importantly, after alignment of the 2 core labs, there was no longer a difference between both treatment groups (%DS of the side branch: treatment group A vs. group B: 34.4 ± 19.4% vs. 32.4 ± 16.1%, p = 0.340). CONCLUSIONS: Originally, a marked inter-core lab variability of bifurcation QCA analysis was found. After alignment of methodology, inter-core lab variability decreased considerably and impacted angiographic trial results. This latter finding emphasizes the importance of using the same methodology among different core labs worldwide. (Tryton Pivotal Prospective, Single Blind, Randomized Controlled Study to Evaluate the Safety & Effectiveness of the Tryton Side Branch Stent Used With DES in Treatment of de Novo Bifurcation Lesions in the Main Branch & Side Branch in Native Coronaries [TRYTON]; NCT01258972).

In vitro validation and comparison of different software packages or algorithms for coronary bifurcation analysis using calibrated phantoms: implications for clinical practice and research of bifurcation stenting.

BACKGROUND: The accuracy and precision of quantitative coronary angiography (QCA) software dedicated for bifurcation lesions compared with conventional single-vessel analysis remains unknown. Furthermore, comparison of different bifurcation analysis algorithms has not been performed. METHODS: Six plexiglas phantoms with 18 bifurcations were manufactured with a tolerance < 10 µm. The bifurcation angiograms were analyzed using Cardiovascular Angiography Analysis System (CAAS; Version 5.10, Pie Medical Imaging, Maastricht, The Netherlands) and QAngio XA (Version 7.3, Medis Medical Imaging System BV, Leiden, The Netherlands) software packages. RESULTS: Conventional single-vessel analysis underestimated the reference vessel diameter and percent diameter stenosis in the proximal main vessel while it overestimated these parameters in the distal main vessel and side branch. CAAS software showed better overall accuracy and precision than QAngio XA (with automatic Y- or T-shape bifurcation algorithm selection) for various phantom diameters including minimum lumen diameter (0.012 ± 0.103 mm vs. 0.041 ± 0.322 mm, P = 0.003), reference vessel diameter (-0.050 ± 0.043 mm vs. 0.116 ± 0.610 mm, P = 0.026), and % diameter stenosis (-0.94 ± 4.07 % vs. 1.74 ± 7.49 %, P = 0.041). QAngio XA demonstrated higher minimal lumen diameter, reference vessel diameter, and % diameter stenosis when compared to the actual phantom diameters; however, the accuracy of these parameters improved to a similar level as CAAS when the sole T-shape algorithm in the QAnxio XA was used. CONCLUSION: The use of the single-vessel QCA method is inaccurate in bifurcation lesions. Both CAAS and QAngio XA (when the T shape is systematically used) bifurcation software packages are suitable for quantitative assessment of bifurcations.

Acute coronary syndromes in patients with atrial fibrillation and heart failure. Could novel oral anticoagulants be the solution of the optimal antithrombotic therapy puzzle?

The patients experiencing an acute coronary event are exposed to increased risk of thromboembolic events. That risk becomes substantially greater when AF fibrillation and heart failure are present as well. Dual antiplatelet therapy remains the gold standard in the treatment of patients with ACS. The combination of an oral anticoagulant agent with dual antiplatelet therapy is proven to be more effective in prevention of further antithrombotic events but is followed by increased risks of clinically significant bleeding thus it is not suggested in the treatment of ACS. However, it has been proven beneficial in patients with AF who present with an acute coronary episode. NOACs have proved to be at least as effective as vitamin K antagonists in protecting patients with atrial fibrillation from thromboembolic events without increased risk of major bleeding. However, only data on the effectiveness of NOACS in patients with ACS and AF have been quite contradictory. Even more, the data on the effect of NOACS in patients with concomitant HF and AF who present with an acute coronary event is almost lacking from current bibliography. In this review, we attempt to describe the available data of the use of NOACS in patients with AF and HF who experience an ACS and to address the need for further studies in this area.

Accumulation of microvascular target organ damage in newly diagnosed hypertensive patients.

Early identification of hypertensive target organ damage (TOD) emerges as important for global cardiovascular risk assessment. Retinal vascular alterations, capillary rarefaction, and microalbuminuria represent different forms of microvascular TOD. However, data regarding their concomitant presence in the early stages of hypertension, the association of the number of affected organs with cardiovascular risk, and aldosterone effect on multiple TOD are lacking. We studied naïve, never-treated patients with recent duration of hypertension and healthy volunteers. Innovative software was developed to estimate retinal vascular diameters and capillary density. Biochemical parameters including microalbuminuria and serum aldosterone were derived. Framingham Risk Score was used to determine cardiovascular risk. In total 103 subjects, 66 hypertensives and 37 normotensives, were included. Hypertensive patients exhibited a greater number of affected target organs compared with normotensives (P = .014), with retinopathy and capillary rarefaction (40.9%) representing the most common TOD among hypertensives. The number of affected organs was linearly correlated with increased Framingham score and serum aldosterone, analyzed with univariate (P < .001 and P = .002) and multivariate analysis (P = .025 and P = .004), respectively. Physicians dealing with hypertensive patients should be aware of the possibility of diffuse microvascular impairment and seek multiple TOD even in the early stages of hypertension.

A CT-based Medina classification in coronary bifurcations: does the lumen assessment provide sufficient information?

AIMS: To evaluate the distribution of atherosclerosis at bifurcations with computed tomography coronary angiography (CTCA) and propose a novel CT-Medina classification for bifurcation lesions. METHODS: In 26 patients (age 55 ± 10 years, 81% male) imaged with CTCA, 39 bifurcations were studied. The bifurcations analysis included the proximal main vessel, the distal main vessel and the side branch (SB). Plaque contours were manually traced on CTCA; the lumen, vessel and plaque area were measured, as well as plaque burden (%). The carina cross-sections were divided into four equal parts according to the expected wall shear stress (WSS) to assess circumferential plaque distribution. All the bifurcation lesions were classified using the Medina classification and a novel CT-Medina classification combining lumen narrowing and plaque burden ≥70%. RESULTS: Presence of severe plaque (plaque burden ≥70%) by CTCA was demonstrated in 12.8% (5/39) of the proximal segments, 15.4% (6/39) of the distal segments and 7.7% (3/39) of the SB segments. The thickest plaque was located more often in low WSS parts of the carina cross-sections, whereas the flow divider was rarely affected. Although in the majority of bifurcations plaque was present, based on the Medina classification 92% of the assessed bifurcations were identified as 0,0,0. Characterization of bifurcation lesions using the new CT-Medina classification provided additional information in seven cases (18%) compared to the Medina classification CONCLUSION: Atherosclerotic plaque is widely present in all bifurcation segments, even in the absence of coronary lumen stenosis. A CT-Medina classification combining lumen and plaque parameters is more informative than angiographic classification of bifurcation lesions and could potentially facilitate the decision-making on the treatment of these lesions.

Acute epigastric and low back pain during amiodarone infusion; is it the drug or the vehicle to blame?

Amiodarone is a Class III antiarrhythmic agent used for cardioversion and prevention of recurrences of atrial fibrillation. However, its use is limited due to its side-effects resulting from the drug's long-term administration. We have described acute epigastric pain following treatment with intravenous amiodarone for atrial fibrillation in a previous report. Hereby, we describe a second patient who suffered acute epigastric pain, as well as one who suffered acute low back pain. Intravenous amiodarone has been related to a series of minor and major adverse reactions, indicating other constituents of the intravenous solution as the possible cause, possibly polysorbate-80. A possible correlation between acute epigastric and low back pain after intravenous amiodarone loading is unproven; however it is of crucial importance for clinicians to be aware of this phenomenon, and especially since an acute epigastric pain is implicated in the differential diagnosis of cardiac ischemia.

Impact of 3-dimensional bifurcation angle on 5-year outcome of patients after percutaneous coronary intervention for left main coronary artery disease: a substudy of the SYNTAX trial (synergy between percutaneous coronary intervention with taxus and cardiac surgery).

OBJECTIVES: This study sought to investigate the impact of left main coronary artery (LMCA) 3-dimensional (3D) bifurcation angle (BA) parameters on 5-year clinical outcomes of patients randomized to LMCA percutaneous coronary intervention (PCI) in the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) trial. BACKGROUND: BA can affect outcome after bifurcation PCI; 3D angiographic analysis provides reliable BA measurements. METHODS: The diastolic distal BA (between left anterior descending and left circumflex) and its systolic-diastolic range were explored. A stratified post-hoc survival analysis was performed for 5-year major adverse cardiac and cardiovascular events (MACCE) (all-cause death, cerebrovascular accident, myocardial infarction, or repeat revascularization), a safety endpoint (all-cause death, cerebrovascular accident, or myocardial infarction), and repeat revascularization. Analysis was performed in patients where 3D BA was available pre- and post-PCI. RESULTS: Of 266 patients eligible for analysis, 185 underwent bifurcation PCI (group B); 1 stent was used in 75 patients (group B1), whereas ≥2 stents were used in 110 patients (group B2). Stratification across pre-PCI diastolic distal BA tertiles (<82°, 82° to 106°, ≥107°) failed to show any difference in MACCE rates either in the entire study population (p = 0.99) or in group B patients (p = 0.78). Group B patients with post-PCI systolic-diastolic range <10° had significantly higher MACCE rates (50.8% vs. 22.7%, p < 0.001); repeat revascularization and safety endpoint rates were also higher (37.4% vs. 15.5%, p = 0.002, and 25.4% vs. 14.1%, p=0.055, respectively). Post-PCI systolic-diastolic range <10° was an independent predictor of MACCE (hazard ratio: 2.65; 95% confidence interval: 1.55 to 4.52; p < 0.001) in group B patients. CONCLUSIONS: A restricted post-procedural systolic-diastolic distal BA range resulted in higher 5-year adverse event rates after LMCA bifurcation PCI. Pre-PCI BA value did not affect the clinical outcome.

Incidence, correlates, and significance of abnormal cardiac enzyme rises in patients treated with surgical or percutaneous based revascularisation: a substudy from the Synergy between Percutaneous Coronary Interventions with Taxus and Cardiac Surgery (SYNTAX) Trial.

AIMS: The aim of the present investigation was to determine the long-term prognostic association of post-procedural cardiac enzyme elevation within the randomised Synergy between Percutaneous Coronary Intervention (PCI) with TAXUS and Cardiac Surgery (SYNTAX) Trial. METHODS: 1800 patients with unprotected left main or de novo three-vessel coronary artery disease were randomised to undergo coronary artery bypass graft (CABG) surgery or PCI. Per protocol patients underwent post-procedural blood sampling with creatine kinase (CK), and the cardiac specific MB iso-enzyme (CK-MB) only if the preceding CK ratio was ≥ 2 × the upper limit of normal (ULN). An independent chemistry laboratory evaluated all collected blood samples. RESULTS: Post-procedural CK sampling was available in 1629 of 1800 patients (90.5%). As per protocol, CK-MB analyses were undertaken in 474 of 491 patients (96.5%) in the CABG arm, and 53 of 61 patients (86.9%) in the PCI arm. Within the CABG arm, despite the limitations of incomplete data, a post-procedural CK-MB ratio <3/≥3 ULN separated 4-year mortality into low- and high-risk groups (2.3% vs. 9.5%, p=0.03). Additionally, in the CABG arm, a post-procedural CK-MB ratio ≥3 ULN was associated with an increased frequency of a high SYNTAX Score (≥33) tertile (high [≥33] SYNTAX Score: 39.5%, intermediate [23-32] SYNTAX Score 31.0%, low [≤22] SYNTAX Score 29.5%, p=0.02). Within the PCI arm, a post-procedural CK ratio of <2 or ≥2 ULN separated 4-year mortality into low- and high-risk groups (10.8% vs. 23.3%, p=0.001). Notably, there was an early (within 6 months) and late (after 2 years) peak in mortality in patients with a post-PCI CK ratio of ≥2 ULN. Lack of pre-procedural thienopyridine, carotid artery disease, type 1 diabetes, and presence of coronary bifurcations were independent correlates of a CK ratio ≥2 ULN post-PCI. CONCLUSION: Cardiac enzyme elevations post-CABG or post-PCI are associated with an adverse long-term mortality; the causes of which are multifactorial.

Advanced three-dimensional quantitative coronary angiographic assessment of bifurcation lesions: methodology and phantom validation.

AIMS: Validation of new three-dimensional (3-D) bifurcation quantitative coronary angiography (QCA) software. METHODS AND RESULTS: Cardiovascular Angiography Analysis System (CAAS 5v10) allows 3-D angiographic reconstructions based on two or more 2-D projection images. Measurements for minimal lumen diameter (MLD), reference vessel diameter (RVD), percent diameter stenosis (DS) and bifurcation angle (BA) were validated against precision manufactured phantom bifurcations. Length measurements were validated against angiographic measurement catheters inserted into a plexiglas bifurcation phantom. In 3-D reconstructions based on two 2-D images, acquired at variable rotation and angulation, accuracy and precision (mean difference ± SD) of the 11-segment model for MLD, RVD and DS were 0.013±0.131 mm, -0.052±0.039 mm and -1.08±5.13%, respectively; inter-observer variability was 0.141 mm, 0.058 mm and 5.42%, respectively. Adding the antero-posterior (optimal) projection to these basic reconstructions resulted in reduced variability (0.101 mm, 0.041 mm and 3.93% for MLD, RVD and DS, p<0.01 for all) and showed a trend towards improved precision (0.109 mm, 0.031 mm and 4.26%, respectively, p>0.05 for all). In basic reconstructions, accuracy and precision for BA was -1.3±5.0°, whereas inter-observer variability was 7.5°; respective measures for length were 0.15±0.26 mm and 0.54 mm. Adding the antero-posterior projection resulted in decreased precision (0.47 mm, p<0.01) and increased variability (1.03 mm, p<0.01) for length measurements; precision (5.4°) and variability (7.9°) for BA did not change significantly (p>0.30). CONCLUSIONS: Advances in the methodology of 3-D reconstruction and quantitative analysis for bifurcation lesions translated into highly accurate, precise and reproducible measures of diameter, length and BA.