Diseased Coronary Segments Research Articles

Comparison between different approaches to evaluate fibrous cap thickness in sequential optical coherence tomography studies.

In this in-vivo human study we tested the reproducibility for optical coherence tomography (OCT) assessment of lumen area (LA) and plaque components measurements, such as lipid arc extension and fibrous cap thickness (FCt). We tested the variability of LA, lipid arc and FCt assessments in two repeated OCT pullbacks from the same diseased coronary segment matched using fiduciary anatomical landmarks. In particular, for the reliability of minimal FCt measurement we compared four different approaches based on continuous (longitudinal) or segmental (spot) individuation of smaller thickness: 1) comparison of single minimal FCt individuated alongside all plaque extension in the two pullbacks (Longitudinal (L)-spot minimal FCt value); 2) comparison of the mean FCt values of the plaque in the two pullbacks (L-plot mean FCt value); 3) comparison between the single minimal FCt value obtained in the first pullback and the single FCt obtained in the matched CS of second pullback (L-spot CS matched FCt value); 4) comparison of measurements obtained by visual selection of CS with minimal FCt s in the two pullbacks (single-spot minimal FCt value). From the paired analyses of 20 non culprit lesions (accounting for a total of 387 matched CS), we found a suboptimal in-segment correlation for LA (Intra-Class Coefficient [ICC] 0.731), but a good in-segment correlation for lipid arc (ICC 0.963). Regarding FCt measurement, a high reproducibility was obtained applying continuous assessment; in particular, the best correlation was observed with L-spot minimal FCt value and the L-plot mean FCt (ICC 0.893 and 0.952, respectively) with small inter-pullback differences (confidence intervals less than 0.04 mm). In this methodological study we observed a good reproducibility for quantitative plaque measurements with OCT confirming its reliability for serial assessment. In particular, longitudinal measurement in multiple adjacent frames seems to be the more accurate and reproducible approach for sequential FCt assessment.

Prevalence of coronary atherosclerosis in individuals with pre-diabetes and diabetes compared to normoglycemic individuals

Abstract Background Patients with type 2 diabetes have a two- to four-fold higher risk of death and cardiovascular events than the general population. Understanding the characteristics of atherosclerosis in people with different stages of dysglycaemia compared to normoglycaemic individuals may be useful for tailored prevention strategies in the future. Purpose To characterise the prevalence of coronary artery atherosclerosis in individuals with prediabetes, previously undetected diabetes and previously known diabetes compared with normoglycaemic individuals in a large population-based cohort. Methods Data were obtained from the Swedish CArdiopulumonary bioImage Study (SCAPIS), a population-based cohort of participants aged 50–64 years. The 25,553 study participants were categorised according to their glycaemic status: normoglycaemic (glucose: <6.1 mmol/L and HbA1c <6.0% (<42 mmol/mol)), pre-diabetes (6.1–6.9 mmol/L and/or elevated HbA1c 6.0–6.5% (42–47mmol/mol)), previously undetected diabetes (glucose ≥7.0 mmol/L and/or HbA1c >6.5% (≥48 mmol/mol)) or known diabetes. Plaque burden (number of diseased coronary segments) was determined by coronary computed tomography angiography (CCTA) in all 18 coronary artery segments. Total coronary artery atherosclerotic burden was assessed by segment involvement score (SIS) ≥4 and any coronary atherosclerosis. Imaging and analyses were performed using a calcium scoring protocol. The calcium content in each coronary artery was measured and summed to obtain an overall coronary artery calcification score (CACS). Results Study participants with dysclycaemia were defined as pre-diabetes (n=3,989, 16%), undetected diabetes (n=648, 2.5%) or known diabetes (n=1,033, 6.5%). The prevalence of CCTA-detected atherosclerosis among study participants, stratified by glycaemic status into four groups, is shown in Figure 1. The distribution of CACS categories by glycaemic status is shown in Figure 2. The association between CACS and glycaemic status, with normoglycemia as reference, was further explored in an adjusted (age, sex and site) ordinal regression: pre-diabetes 1.33 (95% CI 1.25–1.42), undetected diabetes 1.82 (95% CI 1.59–2.09), known diabetes 2.88 (95% CI 2.59–3.20). In a sensitivity analysis excluding people with previous myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention or with stent (n=693), the results were virtually unchanged, pre-diabetes 1.31 (95% CI 1.23–1.40), undetected diabetes 1.80 (95% CI 1.57–2.07), known diabetes 2.73 (95% CI 2.45–3.05). Conclusions The prevalence of coronary atherosclerosis increased substantially with increasing dysglycaemia. Our data suggest that more aggressive screening and/or treatment of individuals with prediabetes and diabetes to prevent cardiovascular disease should be discussed in the future. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The main funding body of The Swedish CArdioPulmonary bioImage Study (SCAPIS) is the Swedish Heart- and Lung Foundation.

Case Report: Structural Changes in the Coronary Vessel Wall in a Patient With Incomplete Kawasaki Disease

BackgroundKawasaki disease (KD) is an acute systemic vasculitis of infants and young children that affects medium-sized vessels. Conventional cardiac imaging techniques, such as cardiac catheterization, are useful for characterizing the coronary arterial lesion (CAL) size and luminal diameter of the diseased coronary artery segment in patients with KD, but there are limitations to the visualization of the detailed vascular anatomy. Optical coherence tomography (OCT) is a high-resolution intracoronary arterial imaging modality that can distinguish the three layers of the coronary arterial wall. Several studies have reported coronary artery wall abnormalities in KD patients with coronary arterial aneurysm or regressed aneurysm. However, there have been no reports on changes in the coronary artery wall in cases of incomplete KD without CAL.Case PresentationWe herein report an 11-year-old girl with a history of incomplete KD without coronary arterial aneurysms. She had been diagnosed with perimembranous ventricular septal defect (VSD) after birth and had experienced incomplete KD at 1 year old. During her hospitalization for KD, she did not receive intravenous immunoglobulin (IVIG), because she did not meet the Harada score or criteria for treatment in patients with incomplete KD established by the American Heart Association. No dilatation or coronary artery aneurysm were observed on transthoracic echocardiography in the acute or follow-up period. At 11 years old, she received cardiac catheterization and coronary angiography (CAG) for the evaluation of a VSD and follow-up of KD. CAG demonstrated no aneurysm, dilatation, or significant stenosis of the coronary arteries. We performed an OCT study, which revealed the presence of intimal thickening, disruption of the media, and neovascularization in the left anterior descending artery.ConclusionOCT demonstrates the structural changes of CA even in the patient with incomplete KD who have not been treated with IVIG.

Platelet reactivity among patients with acute coronary syndromes and multivessel coronary artery disease

Abstract Background Patients with multivessel or complex coronary artery disease (CAD) are at increased risk of atherothrombotic events. It has been suggested that these patients may derive an incremental benefit with more intense antiplatelet strategies, according to prior subgroup analyses from randomized clinical trials. However, whether there is any association between the presence and extension of multivessel CAD and platelet aggregability (PA) in patients with acute coronary syndromes (ACS) is unknown. Purpose To analyze the independent association between PA and presence of multivessel CAD in patients with ACS. Methods Patients with ACS on dual antiplatelet therapy (aspirin plus clopidogrel) were included in this study. Multivessel CAD was defined as the presence of significant ≥50% stenosis at two or more major epicardic vessels. Platelet aggregability was assessed by VerifyNow P2Y12 assay expressed in P2Y12 Reactivity Units (PRU) on the day of discharge from the coronary care unit. High On-treatment platelet reactivity (HPR) was defined as PRU ≥208. Stepwise linear and logistic regression models were applied to adjust for confounders. Models were adjusted for: age, sex, race, diabetes, hypertension, smoking, dyslipidemia, prior MI, prior PCI, prior CABG, prior HF, prior stroke and ACS phenotype (STEMI vs. Non-ST-segment elevation ACS). Results A total of 237 patients were included, among whom 143 (60.3%) had multivessel CAD at the coronary angiogram and 175 (73.8%) were submitted to PCI during index hospitalization. Patients with multivessel disease were older (mean age 64.8±12.1 vs. 58.9±11.2 years; p<0.001) and more likely to have a history of diabetes (47.6% vs. 29.8%; p=0.006) and non-ST-segment elevation ACS as the index event (55.2% vs. 28.7%; p<0.001), compared to patients without multivessel CAD. After adjustments, presence of multivessel CAD was associated with higher PA (mean 161.4±74 PRU in patients with versus 140.3±70.9 PRU in patients without multivessel CAD; adjusted mean difference 23.7 PRU; 95% CI 4.8 to 42.5; p=0.014). Additionally, there was an incremental of 12.5 PRU (95% CI 2.8 to 22.3; adj p=0.012) for each diseased vessel and of 4.67 PRU (95% CI 0.11 to 9.22; adj p=0.045) for each diseased coronary segment. Compared to patients with single-vessel disease, patients with three-vessel disease had higher rates of HPR. (Figure). Conclusion In patients with ACS, the presence and extension of multivessel CAD were associated with higher levels of platelet aggregability and higher rates of high on-treatment platelet reactivity with clopidogrel. This finding may explain the incremental benefit with more intense antiplatelet therapies seen in this particular subgroup in prior clinical trials. Prevalence of HPR and extension of CAD Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Sao Paulo Research Foundation (FAPESP)

Long-Term Prognostic Value of Coronary Atherosclerotic Plaque Characteristics Assessed by Computerized Tomographic Angiography.

We aimed to present the long-term prognostic role of coronary computed tomography angiography (CTA) in a cohort of patients with coronary artery disease (CAD) and noncritical stenosis. A total of 1138 patients who underwent coronary CTA for suspected CAD were included in the study. For the categorization of the coronary atherosclerotic plaque (CAP), the coronary system was divided into 16 segments. For each segment, CAPs were categorized as calcified, noncalcified, and mixed. All-cause and cardiovascular (CV) mortality data were collected for prognostic evaluation. Coronary CTA analyses showed that 34.5% of patients had noncalcified CAP, 14.5% of patients had calcified CAP, and 11% of patients had mixed CAP. During a median of 141.5 months follow-up, CV and all-cause mortality was observed in 57 (5%) and 149 (13.1%) patients, respectively. In multivariable Cox regression analysis, calcified CAP morphology and the extent of involved segments were significant predictors of both CV and all-cause mortality. The presence of calcified CAP morphology and the higher number of diseased coronary segments via coronary CTA might help stratify patients at risk for adverse CV outcomes during long-term follow-up. Patients with these features at index coronary CTA may be evaluated more closely with aggressive preventive measures.

Comparison between different approaches to evaluate fibrous cap thickness in sequential OCT studies.

In this in vivo human study we tested the reproducibility for optical coherence tomography (OCT) assessment of lumen area (LA) and plaque components measurements, such as lipid arc extension and fibrous cap thickness (FCt). We tested the variability of LA, lipid arc and FCt assessments in two repeated OCT pullbacks from the same diseased coronary segment matched using fiduciary anatomical landmarks. In particular, for the reliability of minimal FCt measurement we compared four different approaches based on continuous (longitudinal) or segmental (spot) individuation of smaller thickness: 1) comparison of single minimal FCt individuated alongside all plaque extension in the two pullbacks (Longitudinal (L)-spot minimal FCt value); 2) comparison of the mean FCt values of the plaque in the two pullbacks (L-plot mean FCt value); 3) comparison between the single minimal FCt value obtained in the first pullback and the single FCt obtained in the matched CS of second pullback (L- spot CS matched FCt value); 4) comparison of measurements obtained by visual selection of CS with minimal FCt s in the two pullbacks (Single-spot minimal FCt value). From the paired analyses of 20 non culprit lesions (accounting for a total of 387 matched CS), we found a suboptimal in-segment correlation for LA (Intra-Class Coefficient [ICC] 0.731), but a good in-segment correlation for lipid arc (ICC 0.963). Regarding FCt measurement, a high reproducibility was obtained applying continuous assessment; in particular, the best correlation was observed with L-spot minimal FCt value and the L-plot mean FCt (ICC 0.893 and 0.952, respectively) with small inter-pullback differences (confidence intervals less than 0.04 mm). In this methodological study we observed a good reproducibility for quantitative plaque measurements with OCT confirming its reliability for serial assessment. In particular, longitudinal measurement in multiple adjacent frames seems to be the more accurate and reproducible approach for sequential FCt assessment.

P2242Prognostic impact of CT derived quantified coronary artery plaque volume: A 10 year follow-up study

Abstract Background Automated plaque quantification derived from coronary CT angiogragphy (CCTA) datasets provides exact and reliable assessment of coronary atherosclerosis burden. Purpose To investigate the long-term predictive value of quantified coronary plaque volume (PV) in comparison to Calcium Score (CACS). Methods Dedicated software was used to quantify PV in 1577 patients. A combination of cardiac death and acute coronary syndrome was used as endpoint. Incremental prognostic value was tested with c-statistics and continuous net reclassification improvement (NRI). The Morise Score was used to summarize patients clinical risk profile. Results Patients were followed for 10.4 years. The combined endpoint occurred in 59 patients, of whom 36 suffered from cardiac death, 18 had non-fatal myocardial infarction and 5 presented with unstable angina requiring revascularisation. The additive predictive value of PV and CACS was tested against a baseline model (c-index 0.741) including clinical risk and the number of diseased coronary segments (segment-Involvement score). While PV provided additive prognostic value (rise in c-index to 0.763, p=0.01 and NRI 0.247, p=0.03), CACS did not (c-index 0.749, p=0.2 and NRI 0.162, p=0.12). A threshold of 110.5 mm3, which was established by a previous analysis of our group, provided excellent separation of patients into low (no PV), intermediate (PV <110.5 mm3) and high (PV >110.5 mm3) risk categories based upon quantified PV (see attached Figure). Conclusion Quantification of PV from CCTA datasets provides excellent prognostic information on long-term follow-up.

First report of the use of long-tapered sirolimus-eluting coronary stent for the treatment of chronic total occlusions with the hybrid algorithm.

Coronary chronic total occlusions (CTO) usually coexist with diffusely diseased coronary segments proximal and/or distal to the CTO segment. During percutaneous treatment of CTO, multiple overlapping stents are often needed to treat these long lesions. Aim of this study is to report the first use of long, tapered coronary sirolimus-eluting stents (SES) in this setting. This is a retrospective analysis of 100 consecutive patients undergoing CTO recanalization following the hybrid algorithm. Procedural success rate was 89% (11 failures). Among the successful cases, "conventional" drug-eluting stents(DES) were used in 40(44.9%) patients, while in 49(55%) patients long-tapered SES were attempted with a success rate of 98% (1 cross-over to regular stents). Total stent length in the long-tapered DES group was higher compared to the "conventional" stenting group (76 ± 28 mm vs 46 ± 22 mm, P < .001), with a similar total number of stent (1.6 ± 0.8 vs 1.9 ± 0.8). At quantitative coronary analysis, proximal and distal segment involvement was more extended in patients undergoing long-tapered stenting, with longer overall lesion length. No differences in periprocedural complications and clinical outcomes at a mean follow-up of 303 ± 179 days were observed. The use of long tapered coronary DES is technically feasible and safe for the percutaneous treatment of CTOs, especially for patients presenting with long lesions.

An Outflow Boundary Condition Model for Noninvasive Prediction of Fractional Flow Reserve in Diseased Coronary Arteries.

This paper reports on a new boundary condition formulation to model the total coronary myocardial flow and resistance characteristics of the myocardial vascular bed for any specific patient when considered for noninvasive diagnosis of ischemia. The developed boundary condition model gives an implicit representation of the downstream truncated coronary bed. Further, it is based on incorporating patient-specific physiological parameters that can be noninvasively extracted to account for blood flow demand to the myocardium at rest and hyperemic conditions. The model is coupled to a steady three-dimensional (3D) collocated pressure-based finite volume flow solver and used to characterize the "functional significance" of a patient diseased coronary artery segment without the need for predicting the hemodynamics of the entire arterial system. Predictions generated with this boundary condition provide a deep understanding of the inherent challenges behind noninvasive image-based diagnostic techniques when applied to human diseased coronary arteries. The overall numerical method and formulated boundary condition model are validated via two computational-based procedures and benchmarked with available measured data. The newly developed boundary condition is used via a designed computational methodology to (a) confirm the need for incorporating patient-specific physiological parameters when modeling the downstream coronary resistance, (b) explain the discrepancies presented in the literature between measured and computed fractional flow reserve (FFRCT), and

Current concepts on coronary revascularization using BRS in patients with diabetes and small vessels disease.

Diabetes mellitus (DM) and small vessel (SV) disease are two major predictors of adverse outcome in patients treated by percutaneous coronary intervention (PCI), even when last generation metallic drug-eluting stents (DES) are used. Bioresorbable scaffold (BRS) technology has been recently developed to overcome the disadvantages of metallic DES due to their permanent struts. Through the resorption process, BRS may provide a vascular restoration that appears very attractive especially when distal or diffusely diseased coronary segments are involved, as in diabetic patients and SV disease. However, robust evidence on the use of BRS in diabetics is lacking, and recent data have raised concerns on the use of BRS in SVs, particularly when reference vessel diameter (RVD) is <2.25 mm. This review aims at summarizing current evidence related to the use of BRS in diabetics and SV disease.

Is Complete Revascularisation Mandated for all Patients with Multivessel Coronary Artery Disease?

In multivessel coronary artery disease (MVCAD), myocardial revascularisation can be achieved by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), with complete revascularisation on all diseased coronary segments or with incomplete revascularisation on selectively targeted lesions. Complete revascularisation confers a long-term prognostic benefit, but is associated with a higher rate of periprocedural events compared with incomplete revascularisation. In most patients with MVCAD, the main advantage of CABG over PCI is conferred by the achievement of more extensive revascularisation. According to current international guidelines, PCI is generally preferred in single-vessel disease, low-risk MVCAD or isolated left main disease; whereas CABG is usually recommended in patients with complex two-vessel disease, most patients with three-vessel disease and/or non-isolated left main disease. In patients with MVCAD, the choice on revascularisation modality should depend on a multifactorial evaluation, taking into account not only coronary anatomy, the ischaemic burden, myocardial function, age and the presence of comorbidities, but also the adequacy of myocardial revascularisation.

Characteristics of coronary artery lesion in patients with and without diabetes mellitus.

The goal of this study was to compare the coronary atherosclerotic burden in patients with and without type-2 diabetes by using CT coronary angiography (CTCA). A total of 206 diabetic (mean age 67±11years; male: 136) and 523 non-diabetic patients (mean age 62±13years; male: 323) without history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined, and each diseased segment was classified as showing obstructive lesion (luminal narrowing>50%) or not. Coronary angiography was then performed to confirm diagnosis. Diabetics showed a higher rate of abnormal CAD (76 vs. 53% of patients; p<0.0001) and fewer normal coronary arteries (24 vs. 47%; p<0.0001) compared with non-diabetics. Multi-vessel disease was seen more frequently in patients with diabetes than in patients without diabetes [15% (n=22) vs. 7% (n=62), respectively; p=0.0004]. The per-patient number of segments with plaque (4.5 vs. 2.0, respectively; p<0.0001) and the number of segments with obstructive disease (0.9 vs. 0.5, respectively; p=0.0001) were higher for diabetic patients than for non-diabetic patients. Diabetes was associated with higher coronary plaque burden.

Coronary Computed Tomographic Angiographic Findings in Patients With Kawasaki Disease

Kawasaki disease (KD) is the leading cause of acquired coronary disease in children and may lead to subsequent myocardial ischemia and infarction. Because coronary computed tomographic angiography (CTA) is the most sensitive noninvasive test in patients with atherosclerosis, the aim of this study was to retrospectively evaluate coronary CTA performed in patients with KD for aneurysm, stenosis, and calcified and noncalcified coronary artery disease (CAD). Clinical histories and prior stress and imaging test results were reviewed. Thirty-two patients underwent coronary CTA for KD, and 385 coronary segments were evaluated. Twenty-three of 32 patients had ≥1 diseased coronary segment. There were 20 aneurysms, 7 lesions, and 75 segments (20%) with nonobstructive CAD (16% noncalcified, 2% calcified, and 2% mixed). All nonobstructive and obstructive CAD was in patients with histories of acute-phase coronary artery dilatation or aneurysm (echocardiographic z score 4 to 44), and were almost always associated with normal stress imaging test results on follow-up. No lesion or CAD was found in coronary computed tomographic angiographic studies performed in a control group referred for other indications (n = 32, 422 segments evaluated). The median coronary computed tomographic angiographic dose-length product was 59 mGy cm (interquartile range 32 to 131), the median unadjusted radiation dose was 0.8 mSv (interquartile range 0.4 to 1.8), and the median age- and size-adjusted radiation dose was 1.3 mSv (interquartile range 0.7 to 2.3). In conclusion, high-risk patients with histories of KD had nonobstructive and obstructive CAD not visualized by other noninvasive imaging tests. In properly selected high-risk patients with KD, coronary CTA may identify a subset at increased risk for future coronary pathology who may benefit from medical therapy.

Discordant Association of C‐Reactive Protein With Clinical Events and Coronary Luminal Narrowing in Postmenopausal Women: Data From the Women's Angiographic Vitamin and Estrogen (WAVE) Study

The incidence of cardiovascular events had been shown to be associated with C-reactive protein (CRP). However, it is unclear that the cardiovascular risk associated with CRP is due to progressive coronary narrowing or to other factors such as formation of unstable plaque. This study was designed to determine the effect of baseline CRP on cardiovascular events and on the progression of atherosclerotic narrowing among 423 postmenopausal women with angiographic stenosis between 15% and 75%. Baseline CRP levels may affect cardiovascular events and progression of atherosclerotic coronary artery narrowing among postmenopausal women. Baseline and follow-up (2.8 years) angiographic data were analyzed among 320 women. Women were stratified into 4 quartiles according to baseline CRP levels. The changes in lumen diameter and clinical events in each quartile were compared. The annualized changes in minimal and average lumen diameter in diseased and nondiseased coronary segments were not significantly associated with baseline CRP levels. The composite end point of all-cause mortality and myocardial infarction (MI) increased from 3% (3/107) in the first CRP quartile to 14% (14/98) in fourth CRP quartile (P < 0.001). Similar results were found for cardiovascular death and MI (increased from 1% (2/107) in the first quartile to 11% (11/98) in fourth quartile). The difference remained significant even after adjustment for baseline differences and cardiovascular risk factors. Higher baseline CRP was associated with increased risk of clinical events but was not associated with annualized change in luminal diameters. Thus, increased risk of adverse events among patients with higher baseline CRP events was independent of progression of atherosclerosis as measured by change in minimal or average luminal diameter.

The CABG SYNTAX Score - an angiographic tool to grade the complexity of coronary disease following coronary artery bypass graft surgery: from the SYNTAX Left Main Angiographic (SYNTAX-LE MANS) substudy

The SYNTAX Score (SXscore) has established itself as an important prognostic tool in patients undergoing percutaneous coronary intervention (PCI). A limitation of the SXscore is the inability to differentiate outcomes in patients who have undergone prior coronary artery bypass graft (CABG) surgery. The CABG SXscore was devised to address this limitation. In the SYNTAX-LE MANS substudy 115 patients with unprotected left main coronary artery disease (isolated or associated with one, two or three-vessel disease) treated with CABG were prospectively assigned to undergo a 15-month coronary angiogram. An independent core laboratory analysed the baseline SXscore prior to CABG. The 15-month CABG SXscore was calculated by a panel of three interventional cardiologists. The CABG SXscore was calculated by determining the standard SXscore in the "native" coronary vessels ("native SXscore") and deducting points based on the importance of the diseased coronary artery segment (Leaman score) that have a functioning bypass graft anastomosed distally. Points relating to intrinsic coronary disease, such as bifurcation disease or calcification, remain unaltered. The mean 15-month CABG SXscore was significantly lower compared to the mean baseline SXscore (baseline SXscore 31.6, SD 13.1; 15-month CABG SXscore 21.2, SD 11.1; p<0.001). Reproducibility analyses (kappa [k] statistics) indicated a substantial agreement between CABG SXscore measurements (k=0.70; 95% CI [0.50-0.90], p<0.001), with the points deducted to calculate the CABG SXscore the most reproducible measurement (k=0.74; 95% CI [0.53-0.95], p<0.001). Despite the limited power of the study, four-year outcome data (Kaplan-Meier curves) demonstrated a trend towards reduced all-cause death (9.1% vs. 1.8%, p=0.084) and death/CVA/MI (16.4% vs. 7.0%, p=0.126) in the low compared to the high CABG SXscore group. In this pilot study the calculation of the CABG SXscore appeared feasible, reproducible and may have a long-term prognostic role in patients with complex coronary disease undergoing surgical revascularisation. Validation of this new scoring methodology is required.

Initial stress in biomechanical models of atherosclerotic plaques

Rupture of atherosclerotic plaques is the underlying cause for the majority of acute strokes and myocardial infarctions. Rupture of the plaque occurs when the stress in the plaque exceeds the strength of the material locally. Biomechanical stress analyses are commonly based on pressurized geometries, in most cases measured by in-vivo MRI. The geometry is therefore not stress-free. The aim of this study is to identify the effect of neglecting the initial stress state on the plaque stress distribution.Fifty 2D histological sections (7 patients, 9 diseased coronary artery segments), perfusion fixed at 100mmHg, were segmented and finite element models were created. The Backward Incremental method was applied to determine the initial stress state and the zero-pressure state. Peak plaque and cap stresses were compared with and without initial stress. The effect of initial stress on the peak stress was related to the minimum cap thickness, maximum necrotic core thickness, and necrotic core angle.When accounting for initial stress, the general relations between geometrical features and peak cap stress remain intact. However, on a patient-specific basis, accounting for initial stress has a different effect on the absolute cap stress for each plaque. Incorporating initial stress may therefore improve the accuracy of future stress based rupture risk analyses for atherosclerotic plaques.

Computed tomography coronary angiography in the selection of outlier patients: a feasibility report

This study evaluated criteria, presence and distribution of outlier patients by means of computed tomography coronary angiography (CTCA) in a large institutional database. From a population of 2,881 consecutive patients (1,842 men, mean age 62 ± 13 years) in sinus rhythm who underwent CTCA, we extracted data on patients with suspected coronary artery disease (CAD). We selected patient outliers in the fifth and sixth decades of life with the following criteria: ≥ 3 risk factors and absence of CAD, zero to one risk factors and ≥ 5 diseased coronary segments. Diabetes was excluded from risk factors because of the different impact on CAD. The patient population consisted of 2,432 individuals with suspected CAD (1,495 men, age 62 ± 13 years). The prevalence of obstructive CAD (≥ 50% lumen reduction at CTCA) was 36% (863/2,432). Patients with normal coronary arteries accounted for 34% of the total (837/2,432; 431 men, age 55 ± 14 years). Of these, 210 were in the fifth and 231 in the 6th decade (men 196, women 245); those with ≥ 3 risk factors accounted for 4.2% of the total (102/2,432; men 42, women 60). Patients with ≥ 5 diseased coronary segments accounted for 28% of the total (686/2,432; 510 men, age 68 ± 10 years). Of these, 115 were in the fifth and 270 in the sixth decade (men 309, women 76); those with zero to one risk factors accounted for 3.0% (73/2,432; men 66, women 7). CTCA is a reliable noninvasive diagnostic modality that can be used to identify outlier patients. This will enable dedicated trials aimed at characterising biomarkers and genomics of protective and nonprotective factors against CAD and its complications.

Incidental Visceral and Renal Artery Stenosis in Patients Undergoing Coronary Angiography

Purpose The study aimed to examine the association between incidentally discovered mesenteric artery stenosis, renal artery stenosis (RAS) and coronary artery disease in patients undergoing coronary angiography. Materials and methods We performed a prospective analysis of consecutive patients undergoing routine cardiac catheterisation. Abdominal aortograms in lateral and antero-posterior view were obtained to assess arterial stenosis of the coeliac axis, superior mesenteric artery and renal arteries. Significant arterial stenosis was defined as a narrowing of at least 50% compared with the normal artery. Demographic data and cardiovascular risk factors were analysed. Results The prevalence of visceral artery stenosis (VAS) was 63/450 (14%) including 48/450 (10.6%) cases of coeliac axis stenosis and 15/450 (3.3%) cases of superior mesenteric artery stenosis. Female sex ( p = 0.01), older age ( p = 0.03) and the presence of coronary artery disease ( p = 0.05) were significant predictors for the presence of VAS in univariate analysis. The determinants for VAS in multivariate analysis were female sex and three-vessel coronary artery disease, while two- and three-vessel coronary artery disease was significant for RAS. Conclusion Screening for VAS and RAS in female patients older than 60 years with more than two diseased coronary segments could have a high diagnostic value.

Incidence of subclinical atherosclerosis in asymptomatic type-2 diabetic patients

Type-2 diabetic patients constitute a high-risk population for atherosclerosis. Primary prevention, although recommended, is not well funded. Our aim was to evaluate the degree of subclinical atherosclerosis, in asymptomatic diabetic patients, using coronary multi-slice computed tomography (MSCT) angiography. We prospectively studied 71 diabetic patients without any symptoms or documentation of atherosclerotic disease. Coronary MSCT angiography was performed in all patients and coronary artery calcium score (CACS) was evaluated. The number of diseased coronary segments was determined and classified as obstructive or nonobstructive and fibrolipid or calcified lesions. The mean follow-up was 29.5±6.6 months. Major adverse cardiovascular events were registered. The mean age was 59±10 years, 48% were female patients. The duration of diabetes was 12.5±8.7 years. CACS ranged from 0 to 1293 Agatston units (153±269.1). Image quality was generally good, allowing satisfactory evaluation of most of the coronary artery segments. CACS was 0 in 28 patients, but in nine patients MSCT angiography showed fibrolipid plaques. Obstructive coronary artery disease was present in 26.7% of the patients (5.6% with multivessel disease). During the follow-up period, six major adverse cardiovascular events were detected in patients, five of whom had a CACS more than 100 Agatston units. This study shows a high prevalence of silent atherosclerotic lesions in type-2 diabetic patients, reinforcing the importance of risk factor modification even when calcified disease is absent. Coronary MSCT angiography can be performed to identify the atherosclerotic burden and may be an important test in selecting the patients who are benefiting the most from primary prevention.

Assessment of coronary artery disease and calcified coronary plaque burden by computed tomography in patients with and without diabetes mellitus

PurposeTo compare the coronary atherosclerotic burden in patients with and without type-2 diabetes using CT Coronary Angiography (CTCA).Methods and Materials147 diabetic (mean age: 65 ± 10 years; male: 89) and 979 nondiabetic patients (mean age: 61 ± 13 years; male: 567) without a history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined and each diseased segment was classified as showing obstructive lesion (luminal narrowing >50%) or not. Coronary calcium scoring (CCS) was assessed too.ResultsDiabetics showed a higher number of diseased segments (4.1 ± 4.2 vs. 2.1 ± 3.0; p < 0.0001); a higher rate of CCS > 400 (p < 0.001), obstructive CAD (37% vs. 18% of patients; p < 0.0001), and fewer normal coronary arteries (20% vs. 42%; p < 0.0001), as compared to nondiabetics. The percentage of patients with obstructive CAD paralleled increasing CCS in both groups. Diabetics with CCS ≤ 10 had a higher prevalence of coronary plaque (39.6% vs. 24.5%, p = 0.003) and obstructive CAD (12.5% vs. 3.8%, p = 0.01). Among patients with CCS ≤ 10 all diabetics with obstructive CAD had a zero CCS and one patient was asymptomatic.ConclusionsDiabetes was associated with higher coronary plaque burden. The present study demonstrates that the absence of coronary calcification does not exclude obstructive CAD especially in diabetics.