Intracoronary Ultrasound Research Articles

Hidden Coronary Atherosclerosis Assessment but Not Coronary Flow Reserve Helps to Explain the Slow Coronary Flow Phenomenon in Patients with Angiographically Normal Coronary Arteries.

The significance of the slow coronary flow phenomenon (SCFph), as visualized in patients (pts) with angiographically normal coronary arteries, is controversial. Absolute coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD), non-invasively assessed by a transthoracic color-guided pulsed-wave Doppler (E-Doppler TTE), is a reliable parameter to assess coronary microcirculatory dysfunction (CMD). Mild and angiographically hidden epicardial atherosclerosis (Hath), as visualized by intracoronary ultrasound (IVUS), which could be the clue to atherosclerotic coronary microvascular involvement, has never been investigated together with CFR in patients. This study was aimed at assessing the value of CFR and HA in explaining the SCFph. Methods. Both non-invasive assessment of CFR in the LAD and corrected TIMI frame count assessment of the coronary contrast runoff were performed in 124 pts with angiographically normal coronary arteries. Among the whole group, 32 patients also underwent intracoronary ultrasounds in the LMCA and LAD, and the maximal plaque burden was assessed (Lesion external elastic (EEM) cross sectional area (CSA)—Lesion Lumen CSA/Lesion EEM CSA * 100). We found that 24 of the 124 pts (group 1) had the SCFph and the remaining 100 had a normal runoff (group 2). CFR, evaluated in both groups, was not significantly different, being 2.79 ± 0.79 (Mean ± SD) in group 1 and 2.90 ± 0.8 in group 2 (p = ns); in the pts also examined by IVUS (32 pts), the SCFph was always associated with hidden atherosclerosis, and a plaque burden of ≥33%. On the contrary, in the normal runoff group, any grade of PB was observed (from no athero to a PB > 70%) and remarkably, 10 pts had no signs of athero or just a minimal plaque burden. This resulted in a ROC curve analysis in which PB < 33% had a high negative predictive value (100%) in ruling out the SCFph. In addition, considering a CFR value < 2.21 as an index of coronary microcirculatory dysfunction, we found CMD in 15 pts (15%) in group 1 and in 7 pts (29%) in group 2 (p = ns). In conclusion, the SCFph is strongly connected to epicardial athero to the extent that the absence of hidden coronary athero has a very high negative predictive power in ruling out SCFph. CFR that is based on an endothelium-independent mechanism remains fairly normal in this condition. An endothelium-dependent microcirculatory constriction at rest due to atherosclerotic involvement of the coronary microvascular network is a possible explanation of the SCFph.

Intracoronary Ultrasound Imaging Combined with Traditional Chinese Medicine Nursing Applied in the Treatment of Coronary Heart Disease Patients with Phlegm and Blood Stasis Syndrome

This study was to explore the effect of traditional Chinese medicine (TCM) nursing intervention based on intracoronary ultrasound imaging on patients with coronary heart disease (CHD) and phlegm and blood stasis syndrome (PBSS). 100 hospitalized patients with CHD with Qi deficiency and blood stasis syndrome (QDBSS) were rolled into the experimental (Exp) group (routine nursing intervention) and control (Ctrl) group (TCM nursing intervention, syndrome differentiation nursing), with 50 patients in each group. They underwent the intracoronary ultrasound imaging scanning. The results showed that after intervention, the plaque load (45.08 ± 6.02%), plaque eccentricity index (0.47 ± 0.08%), vascular remodeling index (0.53 ± 0.11%), and vascular external elastic membrane area (8.67 ± 3.06 mm2) of the Exp group were notably inferior to those of the Ctrl group (60.22 ± 5.82%, 0.59 ± 0.08%, 0.71 ± 0.09%, and 10.56 ± 2.31 mm2). The total effective rate in the Exp group (88%) was greatly superior to that of the Ctrl group (68%). In terms of TCM symptom scores, the TCM symptom scores of chest pain, chest tightness, and shortness of breath in the Exp group after intervention (1.07 ± 0.21 points, 0.75 ± 0.27 points, and 0.58 ± 0.12 points) were notably inferior to those in the Ctrl group (1.62 ± 0.28 points, 1.03 ± 0.21 points, and 0.79 ± 0.14 points). In the Exp group, after intervention, the degree of physical activity limitation (67.05 ± 5.08 points), the stable state of angina pectoris (65.28 ± 3.76 points), the frequency of angina pectoris attack (85.92 ± 2.97 points), the degree of treatment satisfaction (75.39 ± 5.94 points), the cognition score of disease (63.56 ± 5.84 points), the levels of triglyceride (1.27 ± 0.41 mmol/L), and total cholesterol (2.24 ± 0.41 mmol/L) were remarkably inferior to the Ctrl group (52.97 ± 4.31 points, 50.77 ± 4.69 points, 71.36 ± 3.77 points, 64.08 ± 5.64 points, 51.77 ± 6.33 points, 2.09 ± 0.57 mmol/L, and 3.06 ± 0.84 mmol/L) (P < 0.05). It suggested that intracoronary ultrasound imaging can clearly display the coronary plaques of patients and accurately evaluate the clinical efficacy of patients with CHD. The TCM nursing program can greatly improve the angina symptoms and quality of life of patients with CHD and PBSS, reduce blood lipid levels, and effectively improve the clinical efficacy of patients.

Double cryoenergy application (freeze-thaw-freeze) at growing myocardium: Lesion volume and effects on coronary arteries late after energy application. Implications for efficacy and safety in pediatric patients.

Cryoenergy is accepted as an alternative to radiofrequency ablation (RFA) in childen for ablation of supraventricular tachycardia substrates. Single cryoenergy application has been shown to be inferior to RFA. Double cryoenergy application has therefore been introduced into clinical practice, but experience concerning efficacy is limited. Coronary artery stenosis has been reported as serious complication after RFA for arrhythmia substrates but not after single cryoablation. The purpose of the study was to assess lesion volume (efficacy) and risk of coronary artery damage (safety), late, that is, 6 months, after double cryoenergy application in a piglet model. Two sequential cycles of cryoenergy were delivered at -75°C for 4 minutes at the atrioventricular groove in five piglets. Animals were restudied after 6 months by coronary angiography and intracoronary ultrasound (ICUS). Ablation lesions were examined histologically and lesion volume was determined by three-dimensional morphometric analysis. Cryolesion volume was 174.04 ± 67.18 mm3 for atrial and 238.69 ± 112.1 mm3 for ventricular lesions (P > .05). Ventricular lesions, 4.06 ± 1.05 mm, were significantly deeper than atrial lesions, 3.58 ± 0.78 mm, (P < .05). In two of the 29 lesions, cryoenergy induced minor coronary artery injury with mild medial and adventitial thickening as well as minimal intimal proliferation, which had neither been detected by coronary angiography nor by ICUS. Late after double cryoenergy application at growing myocardium, subclinical minor affection of the coronary artery wall could be detected with minimal intimal proliferation. As lifetime sequelae of this finding remains unknown, further studies are warranted to address safety of repeated cycles of cryoenergy application for tachycardia substrates in children.

Intracoronary Intimal Thickness in Transplant Recipients of Hepatitis C-Positive Donor Hearts

Purpose Prior to the advent of direct-acting antivirals (DAAs), donor-derived hepatitis C (dd-HCV) viremia predicted poor post-heart transplant (HT) outcomes, including a higher risk of coronary allograft vasculopathy (CAV) and death. Considering the success of DAAs to treat HCV and the shortage of organs for HT, we institutionalized a clinical protocol of using HCV+ donors. Using intracoronary ultrasound (ICUS) in patients acquiring post-HT HCV infection, we examined the risk of CAV in the current era. Methods Between September 1st 2016 and October 2nd 2018, 54 HCV-naive patients and 1 with a history of treated-HCV pre-transplant, underwent HT from HCV-positive donors (follow-up available through October 10th, 2018). Patients were treated with ledipasvir-sofosbuvir (genotype 1) or sofosbuvir-velpatasvir (genotype 3) for 12 or 24 weeks. ICUS of left anterior descending artery was performed at 6-months and 1-year post-HT for those developing donor-derived HCV (dd-HCV) infection using an automated, mechanical pullback at a rate of 1 mm/ second. Results The ICUS data were available for 20 patients at 6-months (cohort A) and 16 patients at 1-year (cohort B); 14 patients had serial data available at 6-months and 1-year (cohort C). Figures A and B show changes in maximum intima thickness (MIT) for the overall sample and cohort C. For cohort C, absolute change in MIT from 6-months to 1-year was +0.15 (median) (Inter-quartile range: -0.03, 0.42) and only one patient had an increase in MIT by >0.5mm. Two patients in cohort A (10%) and 4 patients in cohort B (25%) had angiographic CAV grade 1; one patient in each cohort had known coronary artery disease in the donor heart. None required percutaneous coronary intervention or re-transplant for CAV at 1-year. Conclusion Utilization of HCV-positive donors may represent a viable strategy to expand the donor pool in era of DAAs. Larger scale data on changes in MIT is required to appropriately assess the effect of dd-HCV infection on incident CAV.

Intracoronary Intimal Thickness in Recipients of Hepatitis C-Positive Donor Hearts

Considering the success of direct-acting antivirals (DAAs) to treat hepatitis C (HCV) and the shortage of organs for heart transplantation (HT), we institutionalized clinical protocol of using HCV-exposed donors in selected waitlist candidates. Prior to advent of DAAs, donor HCV viremia predicted poor post-HT outcomes, including higher risk of coronary allograft vasculopathy (CAV). Using intracoronary ultrasound (ICUS) in patients acquiring post-HT HCV infection, we examined the risk of CAV in current era.

Hyperglycemia effect on coronary disease in patients with metabolic syndrome evaluated by intracoronary ultrasonography.

IntroductionMetabolic syndrome (MS) is characterized by dyslipidemia, central obesity, hypertension and hyperglycemia. However, type 2 diabetes mellitus (T2DM) may or may not be present in metabolic syndrome. MS and T2DM are considered important cardiovascular risk factors, but the role of hyperglycemia in coronary disease is still contested in the literature. Therefore, we decided to evaluate the effect of hyperglycemia on the severity of coronary disease in MS patients, with or without T2DM, submitted to coronary angiography (CA) and intravascular ultrasonography (IVUS).Materials and methodsThis is a cross sectional, observational study with 100 MS patients (50% with T2DM), 60% male. All of the patients had been referred for CA procedures. The obstruction was considered severe when stenosis was greater than 70% and moderate if it was between 50–69%. Patients detected with a moderate obstruction by CA were indicated to IVUS. A minimal luminal area of less than 4mm2 detected by IVUS was also considered severe. IDF criteria were used to define Metabolic Syndrome and T2DM diagnosis was defined according to the American Diabetes Association criteria. Student’s t-test and Pearson Chi-square were used for statistical analysis, considering p < 0.05 statistically significant.Results and discussionThe majority of T2DM patients presented severe arterial lesions (74% vs 22%, p<0.001). Using CA procedure, 12% of T2DM had moderate obstructions, compared to 38% of the non-diabetic group (p< 0.05). 8% of patients with moderate lesions by CA were diagnosed with a luminal area less than 4mm2 using IVUS. This luminal area was significantly smaller in the T2DM group than in the control group (3.8mm2 ± 2.42. vs 4.6mm2 ± 2.58, p = 0.03).ConclusionPatients with MS and T2DM submitted to angiography and IVUS, had more severe coronary lesions compared to MS patients without diabetes. This finding suggests that beyond insulin resistance that is present in MS, hyperglycemia may also play a role in the development of atherosclerotic disease. IVUS was useful for diagnosing 8% of severe cases initially considered to be moderate obstructions when using just CA in this scenario.

Effect of serial infusions of reconstituted high-density lipoprotein (CER-001) on coronary atherosclerosis: rationale and design of the CARAT study

High-density lipoprotein (HDL) is believed to have atheroprotective properties, but an effective HDL-based therapy remains elusive. Early studies have suggested that infusion of reconstituted HDL promotes reverse cholesterol transport and vascular reactivity. The CER-001 Atherosclerosis Regression Acute Coronary Syndrome Trial (CARAT) is investigating the impact of infusing an engineered pre-beta HDL mimetic containing sphingomyelin (SM) and dipalmitoyl phosphatidlyglycerol (CER-001) on coronary atheroma volume in patients with a recent acute coronary syndrome (ACS). The CARAT is a phase 2, multicenter trial in which 292 patients with an ACS undergoing intracoronary ultrasonography and showing percent atheroma volume (PAV) greater than 30% are randomly assigned to treatment with ten infusions of CER-001 3 mg/kg or matching placebo, administered at weekly intervals. Intracoronary ultrasonography is repeated at the end of the treatment period. The primary endpoint is the nominal change in PAV. Safety and tolerability will also be evaluated. CARAT will establish whether serial 3 mg/kg infusions of an engineered pre-beta HDL mimetic containing SM and dipalmitoyl phosphatidlyglycerol (CER-001) will regress atherosclerotic plaque in patients with a recent ACS.

Effects of Triple Cryoenergy Application on Lesion Formation and Coronary Arteries in the Developing Myocardium.

To improve long-term outcome after cryoablation of substrates of supraventricular tachycardia, application of two and three consecutive freeze-thaw cycles has been performed. The effect of triple freeze-thaw cycles on lesion formation within developing myocardium and coronary arteries, however, has not been studied yet. In eight piglets (mean age 15 weeks, weight 15-20kg), 30 cryolesions (three consecutive freeze-thaw cycles) were applied to the atrial aspect of both AV valve annuli (n = 18) as well as to ventricular myocardium below the valves (n = 12). Coronary angiography was performed before and after cryoenergy application. The animals were reevaluated by coronary angiography and intracoronary ultrasound (ICUS) after 48h. All hearts were removed for histological examination of the lesions subsequently. After staining (hematoxylin-eosin, desmin immunohistochemistry), lesions was measured by planimetry with a digital virtual miscroscope analysis system and volumes of the cryolesions were calculated. Mean atrial lesion volume was 190.68 ± 167.53 mm3 (n = 18), and mean ventricular lesion volume was 184.34 ± 107.42 mm3 (n = 12). Compared with previously reported data on lesion volumes after single and double freeze-thaw cycles, lesions were significantly larger. Coronary arteries were unaffected on coronary angiography as well as on ICUS. No affection of coronary arteries was found on histological examination. Application of three consecutive freeze-thaw cycles resulted in increased lesion volume compared with single and double freeze-thaw cycles. No affection of the coronary arteries was evident. To evaluate the clinical benefit and safety of triple cryoenergy application for catheter ablation, prospective randomized trials are required.

Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting in Heart Transplant Recipients With Transplant Coronary Arterial Vasculopathy

BackgroundTransplant coronary arterial vasculopathy (TCAV) is a major cause of death after heart transplantation (HTx). Palliative coronary revascularization has been attempted in patients with severe TCAV; however, the outcome has not been fully elucidated. MethodsNinety-six patients who were treated after HTx at our institute between 1999 and 2015 were screened for TCAV. TCAV was defined as >70% stenosis on coronary angiography (CAG) or a maximal intimal thickness of >0.5 mm in the right or left coronary arteries on intracoronary ultrasonography (IVUS). In the present study, the outcomes of patients with severe TCAV who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were investigated. ResultsTCAV containing donor-transmitted atherosclerosis was cumulatively found in 69 patients (71.9% of the total; mean age, 34.6 ± 13.1 years; 52 men; mean follow-up duration, 83.0 ± 60.4 months). Five (7.2%) and 64 (92.8%) of the 69 patients were diagnosed as having TCAV by use of CAG and IVUS, respectively. All 5 patients diagnosed by with the use of CAG underwent coronary revascularization between 1 and 236 months after HTx. Three patients underwent PCI with drug-eluting stents, with a primary success rate of 100%. No angiographic restenosis occurred in 2 patients at 31 and 36 months after PCI, respectively. Meanwhile, 2 patients underwent CABG. No peri-operative complications occurred, and all grafts were patent as assessed by use of CAG at 34 and 5 months after CABG. ConclusionsCoronary revascularization was feasible and effective for severe TCAV with middle-term follow-up.

Automated detection of cardiac phase from intracoronary ultrasound image sequences.

Intracoronary ultrasound (ICUS) is a widely used interventional imaging modality in clinical diagnosis and treatment of cardiac vessel diseases. Due to cyclic cardiac motion and pulsatile blood flow within the lumen, there exist changes of coronary arterial dimensions and relative motion between the imaging catheter and the lumen during continuous pullback of the catheter. The action subsequently causes cyclic changes to the image intensity of the acquired image sequence. Information on cardiac phases is implied in a non-gated ICUS image sequence. A 1-D phase signal reflecting cardiac cycles was extracted according to cyclical changes in local gray-levels in ICUS images. The local extrema of the signal were then detected to retrieve cardiac phases and to retrospectively gate the image sequence. Results of clinically acquired in vivo image data showed that the average inter-frame dissimilarity of lower than 0.1 was achievable with our technique. In terms of computational efficiency and complexity, the proposed method was shown to be competitive when compared with the current methods. The average frame processing time was lower than 30 ms. We effectively reduced the effect of image noises, useless textures, and non-vessel region on the phase signal detection by discarding signal components caused by non-cardiac factors.

High coronary plaque load: a heavy burden

This editorial refers to ‘Coronary atheroma volume and cardiovascular events during maximally intensive statin therapy’[†][1], by R. Puri et al ., on page 3182 Hydroxymethylglutaryl (HMG) CoA-reductase inhibitors, or statins, play an important role in the primary and secondary prevention of coronary heart disease. By inhibiting the enzyme HMG-CoA reductase, statins lower the production of cholesterol in the liver, resulting in lower LDL cholesterol levels. Besides lowering cholesterol levels, statin therapy slows down plaque progression and in some patients even causes plaque regression. In the beginning of the 1990s, the first trials were initiated to assess the effect of statin therapy on plaque dynamics. Randomized trials, such as MARS and REGRESS, used (quantitative) invasive coronary angiography (ICA) to assess luminal stenosis characteristics. Since ICA only allows assessment of the coronary lumen, differences in minimal lumen diameters (MLDs) and mean segment diameters (MSDs) between baseline and follow-up were assessed as a measurement of coronary plaque change.1,2 These early studies demonstrated that moderate dose statin therapy on average reduces plaque progression. Importantly, this was associated with a reduction of major adverse cardiovascular events (MACEs). Of note, it was shown that the beneficial effect of statin therapy is more pronounced in more severe lesions.1 A relative shortcoming of these studies was the inability of ICA to visualize true coronary atherosclerotic burden. Around the same time as the first angiographic studies with statin therapy were executed, a novel method for the assessment of coronary plaque burden was designed; intracoronary ultrasound (ICUS), nowadays known as intravascular ultrasound (IVUS). This invasive method uses ultrasound to create two-dimensional tomographic images of the coronary lumen and vessel wall morphology.3 Since then IVUS is frequently used for coronary plaque assessment and has been widely … [1]: #fn-2

Correlation Between Intracoronary Ultrasound and Fractional Flow Reserve in Long Coronary Lesions. A Three-dimensional Intracoronary Ultrasound Study

Introduction and objectivesIntracoronary ultrasound estimation of the functional significance of intermediate angiographic lesions has mainly been based on measuring the minimal lumen area. These estimates take no account of lesion length and pay insufficient attention to long coronary lesions. MethodsWe included 61 lesions with visual angiographic stenosis of 40% to 70% that required treatment with a ≥20mm stent, studied with ultrasound and fractional flow reserve. Three-dimensional analysis of the ultrasound study was conducted offline and blinded to fractional reserve values. Angiographic and ultrasound parameters were correlated with fractional reserve. ResultsFrom the angiography we obtained data on mean reference diameter (2.87 [0.57] mm), length (29.8 [10.01] mm), and severity of stenosis (50.3% [8.7]%). Mean fractional flow reserve was 0.78 (0.09). We found a weak linear correlation (R) between fractional reserve and the ultrasound parameters that did not include lesion length: fractional reserve-minimal luminal area (R=0.4; P=.003). The correlation was stronger when lesion length was included: fractional reserve–volume of plaque (R=–0.65; P<.0005); fractional reserve–length/mean luminal area (R=0.73; P<.0005). The strongest correlation came from the product of mean stenosis by area multiplied by lesion length (R=−0.78; P<.0005). ConclusionsIn long coronary lesions, the correlation between ultrasound-measured minimal lumen area and functional significance is weak. In these cases, estimates of functional significance should incorporate lesion length or be derived from direct fractional flow reserve measurement.

Compensation of in-plane rigid motion for in vivo intracoronary ultrasound image sequence

Intracoronary ultrasound (ICUS) is an interventional imaging modality that is used to acquire a series of tomographic images from the vascular lumen, for diagnosis and treatment of coronary artery diseases in clinical settings. Motion artifacts caused by cardiac dynamics and the pulsatile blood flow within the vascular lumen, during continuous pullback (non-gated) ICUS image acquisition, hinder visualization of longitudinal cuts, assessment of arterial morphology and hemodynamics, and three-dimensional (3-D) vessel reconstruction. The aim of this study is to develop a method to compensate for in-plane rigid motion in non-gated in vivo ICUS sequences. The signals associated with cardiac motion are first detected from the gray-scale image sequence. They are represented with rigid motion parameters between luminal contours extracted from successive slices. Subsequently, the signals were filtered to separate the dynamic components caused by cardiac motion from those caused by the irregular morphology of the vascular lumen. Dynamic components were then compensated by performing a back transformation of related pixels within the vessel region in each frame. The method is validated by computer-simulation and using real ICUS image data. Possible sources of error are discussed based on the experimental results.

Double Cryoenergy Application (Freeze‐Thaw‐Freeze) at Growing Myocardium: Lesion Volume and Effects on Coronary Arteries Early After Energy Application. Implications for Efficacy and Safety in Pediatric Patients

Data on radiofrequency current application (RFA) at growing myocardium suggest that coronary artery stenosis may occur with a low incidence. Cryoenergy has emerged as an effective alternative to RFA. Although already used in clinical practice, experience with cryoenergy is low due to lack of data concerning effects of a modified double cryoenergy application, a freeze-thaw-freeze cycle, at growing myocardium. Purpose of the study was to assess lesion volume (efficacy) and risk of coronary artery damage (safety) early, 48hours, after modified double cryoenergy application in a piglet model. In 5 piglets, following selective coronary angiography, two sequential cycles of cryoenergy were delivered at -75 °C for 4 minutes, interrupted by thawing for one minute, at the atrioventricular groove. Piglets were restudied after 48hours by coronary angiography and intracoronary ultrasound (ICUS). Ablation lesions were examined morphologically and lesion volume was determined by 3-dimensional morphometric analysis. Lesion volume was 109.21± 39.61mm(3) for atrial and 150.30± 53.21mm(3) (P= 0.02) for ventricular lesions. Lesion depth was not significantly different for atrial, 3.07± 1.08mm, versus ventricular lesions, 3.56± 1.3mm. Cryoenergy induced minor coronary artery damage with medial and adventitial necrosis but a preserved intimal layer was present in 2/31 lesions, which had not been detected by coronary angiography or ICUS. Early after double cryoenergy application, subclinical minor changes of the coronary artery wall could be detected occasionally whereas the intimal layer remained intact. These findings may have implications on efficacy and safety when cryoenergy is applied for tachycardia substrates in pediatric patients.

Association between Vascular Remodelling and Necrotic Core in Coronary Arteries: Analysis by Intracoronary Ultrasound with Virtual Histology®

Background: Anatomopathological studies suggest an as ­ sociation of positive vascular remodeling and vulnerable coronary plaques. The objective of this study was to verify whether there is a correlation between positive vascular remodeling and necrotic core in atherosclerot ic coronary lesions. Methods: We studied 270 cross sections obtained by Virtual Histology  in 30 patients who had positive re ­ modeling in coronary artery segments with lesions  50%, identified by coronary angiography. Seven cross sections were assessed per segment of coronary artery, including the cross section with the highest remodeling index, denominat ed cross section of interest (cross section 4). Results: Mean age was 60.8  8.8 years, 80% were male and 30% were diabetic. Unstable angina was the most frequent clinical presentation (56.6%) and the left anterior descending artery was the most analyzed vessel (43%). The vessel reference area was 15.5  4.9 mm² and the remodeling index in cross section 4 was 1.2  0.1. Repeated measures analysis of variance showed a higher percentage of necrotic core in the cross section of interest (P  0.001). We observed a positive correlation of coronary artery remodeling and necrotic core (r = 0.79; P  0.001). Conclusions: Positive coronary artery remodeling is associated to the presence of necrotic core, which characterizes vulnerable athe­ rosclerotic plaques. The search for positive arterial remo­

Association between Vascular Remodelling and Necrotic Core in Coronary Arteries: Analysis by Intracoronary Ultrasound with Virtual Histology®

Anatomopathological studies suggest an association of positive vascular remodeling and vulnerable coronary plaques. The objective of this study was to verify whether there is a correlation between positive vascular remodeling and necrotic core in atherosclerotic coronary lesions. We studied 270 cross sections obtained by Virtual Histology® in 30 patients who had positive remodeling in coronary artery segments with lesions > 50%, identified by coronary angiography. Seven cross sections were assessed per segment of coronary artery, including the cross section with the highest remodeling index, denominated cross section of interest (cross section 4). Mean age was 60.8 ± 8.8 years, 80% were male and 30% were diabetic. Unstable angina was the most frequent clinical presentation (56.6%) and the left anterior descending artery was the most analyzed vessel (43%). The vessel reference area was 15.5 ± 4.9 mm2 and the remodeling index in cross section 4 was 1.2 ± 0.1. Repeated measures analysis of variance showed a higher percentage of necrotic core in the cross section of interest (P < 0.001). We observed a positive correlation of coronary artery remodeling and necrotic core (r = 0.79; P < 0.001). Positive coronary artery remodeling is associated to the presence of necrotic core, which characterizes vulnerable atherosclerotic plaques. The search for positive arterial remodeling may be a useful strategy for detecting vulnerable plaques before rupture. Associação entre Remodelamento Vascular e Núcleo Necrótico em Artérias Coronárias: Análise por Ultrassom Intracoronário com Histologia Virtual® Estudos anatomopatológicos sugerem a associação de remodelamento vascular positivo e placas coronárias vulneráveis. O objetivo deste estudo foi avaliar se existe correlação entre o grau de remodelamento vascular positivo e o porcentual de núcleo necrótico em lesões ateroscleróticas coronárias. Foram estudados 270 cortes transversais obtidos pela Histologia Virtual® de 30 pacientes, os quais apresentavam remodelamento positivo em segmento de artéria coronária com lesão > 50%, identificada pela angiografia coronária. Foram avaliados 7 cortes transversais por segmento de artéria coronária, incluindo o corte transversal com o maior índice de remodelamento arterial, denominado corte transversal de interesse (corte transversal 4). A média de idade foi de 60,8 ± 8,8 anos, 80% eram do sexo masculino e 30% diabéticos. Angina instável foi a apresentação clínica mais frequente (56,6%) e a artéria descendente anterior foi o vaso mais analisado (43%). A área de referência do vaso foi de 15,5 ± 4,9 mm2 e o índice de remodelamento no corte transversal 4 foi de 1,2 ± 0,1. Análise de variância de medidas repetidas mostrou maior porcentual de núcleo necrótico no corte transversal de interesse (P < 0,001). Observamos correlação positiva do remodelamento arterial coronário com o núcleo necrótico (r = 0,79; P < 0,001). O remodelamento positivo da artéria coronária está associado à presença de núcleo necrótico, o qual caracteriza placas ateromatosas vulneráveis. A pesquisa de remodelamento arterial positivo pode ser estratégia útil para a detecção de placas vulneráveis antes de sua ruptura.

TCT-266 Frequency of Spotty Calcification Among Lipid-Core Plaques Using Combined Intracoronary Near-infrared Spectroscopy and Intravascular Ultrasound

TCT-266 Frequency of Spotty Calcification Among Lipid-Core Plaques Using Combined Intracoronary Near-infrared Spectroscopy and Intravascular Ultrasound

Transient Impairment of Vasomotion Function After Successful Chronic Total Occlusion Recanalization

The aim of our study was to assess coronary vasomotion after successful revascularization of chronic total occlusion (CTO). It is largely unknown whether the recovery of anterograde flow after CTO recanalization with drug-eluting stent implantation affects vascular function in distal coronary segments. One hundred consecutive CTOs successfully treated with drug-eluting stents underwent coronary diameter measurement after intracoronary nitroglycerin injection 5, 20, and 35 mm distal to the stented coronary segment using 3-dimensional quantitative coronary angiography. In a subgroup of 14 patients, coronary vasomotion was tested in distal segments: incremental atrial pacing for endothelium-dependent cases; and intracoronary nitroglycerin injection for endothelium-independent cases. In another subgroup of 13 patients, distal vessels were assessed by intracoronary ultrasounds. Vessel diameters significantly increased at follow-up as compared to baseline values (2.0 ± 0.52 mm vs. 2.25 ± 0.50 mm, 1.76 ± 0.49 mm vs. 2.05 ± 0.58 mm, 1.54 ± 0.53 mm vs. 2.04 ± 0.58 mm, at each segment analyzed; p < 0.001). At baseline, distal segments failed to respond to both endothelium-dependent and -independent stimuli. At follow-up, atrial pacing induced vasoconstriction, whereas nitroglycerine administration resulted in significant vasodilation (p < 0.05). Intracoronary ultrasounds failed to show changes of the cross-sectional area of distal segments at follow-up angiography. Recanalization of CTO is followed by a hibernation of vascular wall at distal coronary segments that fail to respond to endothelium-dependent and -independent stimuli. Distal vessel diameter increases over time in the absence of positive remodeling and in spite of persistent endothelial dysfunction. This severe impairment of vasomotor tone after CTO reopening suggests that intracoronary ultrasound assessment is of paramount importance for the selection of stent size.

Coronary plaque burden in patients with stable and unstable coronary artery disease using multislice CT coronary angiography

We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris. Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available ≥2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS). Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as ≥1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6±1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p<0.05). MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.

Assessment of Dynamic Coronary Plaque Changes and the Clinical Consequences in Type-II Diabetic Patients: a Serial Intracoronary Ultrasound Study

Introduction and objectives One of the aims of secondary prevention is to achieve plaque stabilization. This study sought to investigate the clinical consequences and predictive factors of the change in the type of plaque (CTP) as assessed by serial intracoronary ultrasound in type II diabetic patients with known coronary artery disease. Methods 237 segments (45 patients) from the DIABETES I, II, and III trials were included. Intracoronary ultrasound from motorized pullbacks (0.5 mm/s) after index procedure and at 9-month angiographic follow-up was performed in the same coronary segment. Nontreated mild lesions (angiographic stenosis < 25%) with ≥0.5 mm plaque thickening and ≥5 mm of length assessed by intracoronary ultrasound were included. As different types of plaques may be encountered throughout a given coronary lesion, each study lesion was divided into 3 segments for serial quantitative and qualitative analyses. Statistical adjustment by multiple lesion segments per patient (generalized estimating equations method) was performed. A CTP was defined as any qualitative change in plaque type at follow-up. At 1-year follow-up, major adverse cardiac events – death, myocardial infarction and target vessel revascularization) – were recorded. Results A CTP was observed in 48 lesions (20.2%) and occurred more frequently (52.1%) in mixed plaques. Independent predictors of CTP were glycated hemoglobin levels (odds ratio [OR] 1.2; 95% confidence interval [CI] 1.01-1.5; P = .04); glycoprotein IIb-IIIa inhibitors (OR 0.3; 95% CI 0.1-0.7; P = .004) and statin administration (OR 0.3; 95% CI 0.1-0.8; P = .02). At 1-year follow-up CTP was associated with an increase in major adverse cardiac events rate (CTP 20.8% vs non-CTP 13.8%, P = .008; hazard ratio = 1.9, 95% CI 1.3-1.9, P = .01). Conclusions Qualitative changes in mild stenosis documented by intracoronary ultrasound in type II diabetics are associated with suboptimal secondary prevention and may have clinical consequences.