Modified American Heart Association Classification Research Articles

Insights Of Cardiac Changes In Sudden Deaths In Kalaburagi District- An Autopsy Study.

Introduction: Sudden and unexpected death often arises as a complication of diverse cardiac ailments. The occurrence of sudden cardiac-related deaths is increasingly prevalent in both urban and rural settings. This surge presents a formidable challenge for forensic physicians tasked with conducting autopsies to ascertain the precise cause and manner of death, particularly in individuals previously considered healthy. Consequently, this study aims to shed light on infrequent lesions that may go unnoticed during the individual's lifetime, offering valuable insights into this phenomenon. Aims and Objectives of the study: 1) To study the demographic distribution of cardiac specimens of sudden death. 2) To study the histomorphology features in cardiac specimens in sudden death. 3) To grade the atherosclerotic lesions as per Modified American Heart Association Classification of Atherosclerotic Lesion. Materials and method: This is a retrospective study of 3 years from December 2020 to November 2023.The data of medicolegal autopsies was retrieved from the records of department of Pathology, Gulbarga Institute of Medical Sciences, Kalaburagi. A total of 371 medicolegal autopsy specimens were received in the department. Out of which 114 cardiac specimens (sent with other organs) of sudden death were studied. Results: Out of 114 cases of sudden death, 57% of the deaths occurred in outdoor location and remaining 43% occurred in hospitalized patients and homes. The commonest age group of sudden cardiac death was 31 to 40 years of age (27%). We found males were affected more commonly (84%) than females. The most common cause of sudden cardiac death is coronary artery disease (74.6%) followed by myocardial infarction (7.6%). Conclusion: The most common cause of sudden cardiac death is coronary artery disease, which is common in young males (age group 31-40 years).

Arterial Histology in Amputated Limbs with Chronic Limb-Threatening Ischemia and Cadaver Limbs

ObjectiveThe study objectives were to 1) elucidate the histopathological and structural alterations in the femoral to popliteal arteries and tibial or more distal arteries in patients with chronic limb-threatening ischemia through detailed histomorphological and histopathological examinations of the lower limb arteries in the amputated limbs; and 2) elucidate the basic structure of the entire lower extremity, from the external iliac artery to the digital artery, based on histomorphological examinations of cadaver limbs. MethodsWe examined the histopathology and histomorphology of lower limb arteries harvested from 22 amputated limbs and that from 11 cadavers without lower limb issues. Sixty-three sections from the amputated limbs were categorized into femoropopliteal, tibial, and distal segments. Five hundred ten sections (from the external iliac artery to the digital artery) from the cadavers were categorized as femoropopliteal segments, tibial and distal segments, and others. The modified American Heart Association classification was used for the histopathological analysis, and the advanced lesion was defined as the presence of progressive atherosclerotic lesion. In the histomorphological analyses, we calculated %stenosis, %medial area as the medial area divided by the area within the external elastic lamina × 100, and %intimal area as the intimal area divided by the area within the external elastic lamina × 100. ResultsIn amputated limbs, advanced lesions and calcification in the medial area were more prevalent in the femoropopliteal segments than in the tibial and distal segments (advanced lesion: 8/10 vs. 18/42, p=0.048; calcification: 10/10 vs. 28/42, p=0.037), while %stenosis and prevalence of luminal thrombi were comparable. Significant inverse correlations were noted between %medial area and external elastic lamina diameter in both amputated (r=-0.641, p<0.001) and cadaver limbs (r=-0.775, p<0.001). In the femoropopliteal segments of the amputated limbs, luminal stenosis was solely caused by intimal lesions, whereas in the tibial and distal segments, medial area thickening contributed to luminal stenosis when intimal lesions were less pronounced. When the external elastic lamina diameter was entered as a covariate, the medial area of the 178 cadaver tibial and distal segments with minimal intimal lesions (<40% intimal area) was significantly greater when >75% stenosis was present in the femoropopliteal segments (p<0.001). ConclusionAdvanced lesions in the tibial and distal segments are less prevalent compared to the femoropopliteal segments. Medial area thickening may contribute to luminal stenosis in the tibial and distal segments when intimal lesions were less pronounced, which may be secondary to a significant proximal occlusive lesion.

Transcranial Doppler detects micro emboli in patients with asymptomatic carotid stenoses undergoing endarterectomy

ObjectiveThe objective of this study was to assess the primary endpoint defined as the detection of micro-embolic signals (MES) by the use of transcranial Doppler (TCD) in patients with asymptomatic carotid stenosis (≥70%) scheduled for carotid endarterectomy. The secondary endpoint consisted of testing the association of MES with stenosis severity, histopathological, and ultrasound characteristics. MethodsThis was a single-center, single-arm, prospective, observational trial. Computed tomography angiography and ultrasound assessment (Geroulakos classification) were mandatory as well as being under best medical therapy. MES number and characteristics were investigated in Holter mode TCD-X device with a standard 1.5 MHz probe. The time points of evaluation were: 24 hours preoperative, 24 hours postoperative, and 30 days postoperative. The histopathological analysis was performed according to the modified American Heart Association classification. One-way analysis of variance tested MES differences over time. Univariable and multivariable logistic regression tested variables potentially associated with MES. ResultsA total of 120 patients demonstrated a significant reduction of the mean number of MES (3.35 ± 10.04 and 0.82 ± 2.39; pre- and post-carotid endarterectomy, respectively), becoming undetectable at 30 days (P = .001). Hypoechogenic plaques assessed by ultrasound were a significant risk factor for MES (P = .001). The features of plaque vulnerability, such as hemorrhagic component (P = .011), neovascularization (P = .025), signs of inflammation (P = .027), and rupture of the fibrous cap (P = .002) were predictors of MES. Cap rupture was the only predictor in the multivariate analysis (odds ratio, 5.98; P = .030). The stenosis severity was not associated with MES (P = .95) ConclusionsPatients under best medical therapy had a preoperative embolic activity becoming no more detectable after surgery. Both ultrasound and histologic markers of vulnerability were predictors of MES, and stenosis severity was not associated. TCD gives better insight into the real embolic risk, and future studies should evaluate clinical results coming from its implementation with standard imaging techniques.ClinicalTrial.gov registration number NCT05134493.

Atherosclerosis in coronary arteries and aorta by modified American heart association classification: An autopsy study

Ischemic heart disease following atherosclerosis is a leading cause of deaths among Indians. The study was formulated to assess the Histomorphological atherosclerotic changes in coronaries and aorta in autopsy by applying Modified American Heart Association Classification (AHA) among the autopsy cases received at SIMS &amp; RC, Bangalore.1. To evaluate the autopsies for atherosclerosis in coronary arteries and aorta. 2. To classify atherosclerosis in coronary arteries (right coronary, left coronary, left anterior descending) and aorta by Modified American Heart Association classification (Grade 1-8).Autopsy was studied for 49 cases from June 2019 to August 2019. It was conducted by conventional method and heart was dissected along the flow of blood. Grossly macro-assessment was done and on histopathology examination microscopic assessment was done using Modified American Heart Association Classification.A total of 49 cases were studied, of which 42 cases were male and 7 were females. Male to female ratio was around 6:1. Coronary showing major occlusion was Left Anterior Descending followed by Right Coronary and then Left Circumflex artery. Major number of cases were belonging to grade 4 (59.1%) followed by in grade 3 (38.7%). Calcification was noted in 6 cases (12.2%) and ruptured plaque in 4 (8.16%). With the cardiovascular diseases attaining pandemic proportions, the study of atherosclerosis and its grading is the need of hour to estimate disease burden. Autopsy studies play a vital role in unraveling the spectrum and occurrence of atherosclerosis.

Intra-Plaque Vessels on Contrast-Enhanced Ultrasound Sonography Predict Carotid Plaque Histology

Background and Purpose: Although the echogenicity of carotid plaques on carotid enhanced ultrasound (CEUS) was reported to correlate with the historological density of intra-plaque neovessels, it is unclear whether the intra-plaque vessel size is associated with carotid plaque vulnerability. We evaluated the relationship of size of intra-plaque vessels on CEUS with carotid plaque histology. Methods: We prospectively registered patients with carotid stenosis who were hospitalized to receive carotid endarterectomy between 2012 and 2016. CEUS was performed by ultrasound specialists using a 7-MHz linear transducer (GE LOGIQ7; GE Healthcare, Milwaukee, WN, USA). Sonazoid® was used for conducting CEUS. The sizes of microbubbles inside the plaques were scored at 0, 1, 3, and 5 min after the injection of contrast agent, and were categorized according to our defined vascular score (Vas-S; 0: the effect of contrast was not recognized; 1: the microbubbles were visible, but so blurred and vague that their shape could not be recognized; 2: dot or string-like microbubbles with movement, localized in part or the whole site of the plaque). At histological examination, we simplified the modified American Heart Association classification and defined as an atherosclerotic category (Ath-cat; 1: unruptured plaque; 2: ruptured plaque; 3: healed plaque). We then assessed the correlation of Vas-S with Ath-cat, which describes the process of rupture and restoration of carotid plaques. Results: A total of 97 patients were included in this study. A higher Ath-cat was significantly associated with higher Vas-S at any time. Spearman signed-rank test indicated that Vas-S at 1 min was most strongly correlated with Ath-cat (ρ = 0.43, p = 0.001). Receiver operating curve analysis indicated that a Vas-S of 0 at 1 min was significantly associated with an unruptured plaque (area under curve [AUC] 0.72, p = 0.006), while a Vas-S of 2 at 1 min was significantly associated with a healed plaque (AUC 0.72, p = 0.001). Conclusion: Vas-S values of 0 and 2 at 1 min indicated unruptured and healed plaques respectively. Thus, a Vas-S of 1 at 1 min is an indicator of a ruptured plaque. The intra-plaque vessel size on CEUS was significantly associated with carotid plaque histology, and may predict the process of plaque rupture and restoration.

Morphological spectrum of atherosclerotic lesions in a tertiary care Institute in Punjab

Background: The incidence of coronary artery disease (CAD) has risen considerably in developing world due to industrialization, urbanisation and lifestyle changes, especially among Indians and South Asians. The onset of CAD has been seen to occur at an early age and the severity of the disease and mortality associated with CAD has also increased. The pathology of atherosclerosis needs to be re-evaluated to develop targeted therapy which can contain the disease process at the earliest stage.&#x0D; Aims and Objectives: Most of the morphological studies on atherosclerosis have been done on autopsy cases. In this study, we have analysed the morphological spectrum of atherosclerotic lesions in live patients.&#x0D; Materials and Methods: We retrospectively analysed the histopathology slides of 85 cases whose endarterectomy plaques were received in the Department of Pathology over a period of three and half years (January 2014 to June 2017) and classified the lesions according to Modified American Heart Association classification of atherosclerosis.&#x0D; Results: The average age of patients was 60 years and male to female ratio of 4.3:1. Left anterior descending artery was the commonest vessel involved (52.4%). Majority of the cases had fibrocalcific plaques,followed by fibrous cap atheroma and calcified nodules.&#x0D; Conclusion: Coronary artery plaques were found even in patients less than 40 years old. Aggressive lipid defense therapy needs to be the cornerstone of management of CAD.

Insights Into Echo-Attenuated Plaques, Echolucent Plaques, and Plaques With Spotty Calcification: Novel Findings From Comparisons Among Intravascular Ultrasound, Near-Infrared Spectroscopy, and Pathological Histology in 2,294 Human Coronary Artery Segments

Three intravascular ultrasound (IVUS) signatures have been associated with coronary artery disease instability: echo attenuation, an intraplaque echolucent zone, and spotty calcification. The aim of this study was to investigate the substrates responsible for these IVUS signatures in a relatively large series of post-mortem human coronary samples. The exact mechanisms and pathological correlates underlying echo attenuation, an intraplaque echolucent zone, and spotty calcification remain poorly understood. IVUS was compared with near-infrared spectroscopic detection of lipid core plaque and histopathology in 2,294 vessel segments from 151 coronary specimens from 62 patients at necropsy using the modified American Heart Association classification. IVUS detected echo-attenuated plaques in 18.3% of segments, echolucent plaques in 10.5% of segments, and spotty calcification in 14.4% of segments. Histopathologically, 91.4% of echo-attenuated plaques corresponded to either a fibroatheroma (FA) with a necrotic core (NC) or pathological intimal thickening with a lipid pool; almost all segments with superficial echo attenuation indicated the presence of an FA with an advanced NC. Echolucent plaques indicated the presence of a relatively smaller lipid or NC compared with echo-attenuated plaques (thickness: 0.51 mm [interquartile range (IQR): 0.35 to 0.64 mm] vs. 0.70 mm [IQR: 0.54 to 0.92 mm] [p < 0.001]; arc: 74.5° [IQR: 59.0° to 101.0°] vs. 90° [IQR: 70.0° to 112.0°] [p < 0.001]), although 82.8% of superficial echolucent zones indicated an NC-containing FA. IVUS spotty calcification, especially when superficial in location (72.6%), was often associated with an FA with calcium deposits and had smaller arcs of calcium in the setting of FA compared with fibrocalcific plaques (37.5° [IQR: 23.0° to 53.0°] vs. 59.0° [IQR: 46.0° to 69.0°]; p < 0.001). Comparisons between IVUS and near-infrared spectroscopy revealed that echo-attenuated plaques contained the highest probability of near-infrared spectroscopy-derived lipid core plaque, followed by echolucent plaques and spotty calcifications. This study demonstrated that echo-attenuated plaque, especially superficial echo attenuation, was the most reliable IVUS signature for identifying a high-risk plaque (i.e., an FA containing a large NC).

Advanced atherosclerosis is associated with increased medial degeneration in sporadic ascending aortic aneurysms

ObjectiveThe pathogenesis of non-familial, sporadic ascending aortic aneurysms (SAAA) is poorly understood, and the relationship between ascending aortic atherosclerosis and medial degeneration is unclear. We evaluated the prevalence and severity of aortic atherosclerosis and its association with medial degeneration in SAAA. Methods and resultsAtherosclerosis was characterized in ascending aortic tissues collected from 68 SAAA patients (mean age, 62.9 ± 12.0 years) and 15 controls (mean age, 56.6 ± 11.4 years [P = 0.07]) by using a modified American Heart Association classification system. Upon histologic examination, 97% of SAAA patients and 73% of controls showed atherosclerotic changes. Most SAAA samples had intermediate (types 2 and 3, 35%) or advanced atherosclerosis (types ≥ 4; 40%), whereas most control samples showed minimal atherosclerosis (none or type 1, 80%; P < 0.001 after adjusting for age). In a separate analysis, we examined the total incidence and grade distribution of medial degenerative changes among SAAA samples according to atherosclerosis grade. Advanced atherosclerosis was associated with higher grades of smooth muscle cell depletion (P < 0.001), elastic fiber depletion (P = 0.02), elastic fiber fragmentation (P < 0.001), and mucopolysaccharide accumulation (P = 0.04). Aortic diameter was larger in SAAA patients with advanced atherosclerosis than in patients with minimal (P = 0.04) or intermediate atherosclerosis (P = 0.04). Immunostaining showed marked CD3+ T-cell and CD68+ macrophage infiltration, MMP-2 and MMP-9 production, and cryopyrin expression in the medial layer adjacent to atherosclerotic plaque. ConclusionsSAAA tissues exhibited advanced atherosclerosis that was associated with severe medial degeneration and increased aortic diameter. Our findings suggest a role for atherosclerosis in the progression of sporadic ascending aortic aneurysms.

Atherosclerosis in coronary artery and aorta in a semi-urban population by applying modified American Heart Association classification of atherosclerosis: An autopsy study

Background:Ischemic heart disease (IHD) following atherosclerosis is a giant killer and the incidence of atherosclerosis in coronary arteries is rapidly increasing among Indians. The study was formulated to assess the histomorphological atherosclerotic changes in aorta and coronary arteries at autopsy by applying the modified American Heart Association classification of atherosclerosis based on morphological descriptions to find out the age and sex related prevalence of atherosclerosis in the semi-urban population of Kolar, a district in Southern India.Materials and Methods:Autopsy was conducted on 113 cases whose age ranged from 8-85 years. Autopsy was conducted by the conventional technique; heart and the aorta were removed and fixed in 10% formalin. The heart was dissected along the direction of flow of blood and aorta along the posterior surface. Microscopic assessment of the three main coronary arteries and aorta was done using the modified American Heart Association classification of atherosclerosis. Proportions were analyzed using Chi-square test.Results:The number of males was 78 (69%) and number of females was 35 (31%). Mean age was 37.11 ± 15.69 years. Increased incidence of intermediate lesions was noted in young individuals (15-34 yrs). Atherosclerotic lesions were more in left anterior descending artery compared to other coronary arteries and in abdominal aorta compared to thoracic and ascending aorta. Vulnerable plaques were more in right coronary artery.Conclusion:With cardiovascular disease attaining pandemic proportions, the study of subclinical atherosclerosis is the need of the hour to estimate the disease burden in the asymptomatic population. The increased amount of atherosclerosis (advanced and intermediate lesions) found in the young population in this study gives an indication that anti-atherogenic preventive measures need to be implemented in young individuals, so as to prevent coronary artery disease from causing premature death.

Is Being Tall Cardioprotective? Correlation Between Height And Atherosclerosis. An Autopsy Study

Objectives: Ischemic heart disease (IHD) following atherosclerosis is the most common cause of cardiac deaths worldwide. Short stature has been said to be associated with an increased risk of coronary heart diease (CHD) in many Western populations but contradictory reports have emerged from Asian studies and a few Western studies. Degree of atherosclerosis being an indicator of future IHD, its association with height of the subjects was assessed in the present study. Materials and Methods: Hearts and aortas from 120 autopsies, 82 male and 38 female were assessed. Most patients had died of non-vascualar causes except for two who died of myocardial infarction. Height was measured to the nearest 0.5 cms using flexible measuring tape. Atherosclerosis was microscopically assessed using the modified American Heart Association classification based on morphological descriptions. The results were statistically analyzed using the SPSS software for Windows version 16 using Pearson\'s Chi-square. Results: The degree of atherosclerosis of the coronaries and aortas of short and tall males and only coronaries of short and tall females showed that the difference was not statistically significant (p > 0.05). However the difference in degree of atherosclerosis of aorta of tall and short females was statistically significant (p = 0.02). Conclusion: These data refute the hypothesis that stature is inversely related to risk of CHD. The hypothesis that short stature is an adverse risk factor for CHD has been studied mainly in the Western populations and it does not seem to hold true in the present study done in a rural South Indian population of Kolar. Further prospective follow up studies and autopsy studies are required to confirm and apply these findings to the Indian scenario. Keyword: Atherosclerosis, height, autopsy

Variation in atherosclerotic plaque composition according to increasing coronary artery calcium scores on computed tomography angiography

Increasing coronary artery calcium scores (CACS) are independently associated with cardiac events. Recent advents in coronary computed tomography angiography (CCTA) have allowed us to better characterize individual plaque. Currently, it is unknown if higher CACS are likely to be associated with more calcified or mixed and heterogeneous plaque burden on CCTA. The study population consisted of 1,043 South Korean asymptomatic subjects (49 ± 10 years, 62% men) who underwent CCTA (64-slice MDCT). Plaques were classified on contrast-enhanced CCTA as non-calcified, mixed, and calcified on a per-segment basis according to the modified American Heart Association classification. The majority of the study participants had no coronary calcification (n = 866, 83%), whereas CACS> 0 was observed in 177 participants (17%). Only 40 (5%) participants in absence of CACS had exclusively non-calcified plaque, whereas 10 (1.2%) had significant coronary artery disease. With increasing CACS, study participants were more likely to have exclusively mixed or combination atherosclerotic plaques (P = 0.001). Among individuals with CACS 1-10, the prevalence of at least two coronary segments with mixed plaques was 4%, increasing up to 18 and 41% with CACS of 11-100 and >100. The respective prevalence of ≥2 coronary segments (calcified plaques) with increasing CACS were 6%, 16 and 26% (P = 0.01) and of non-calcified plaques were 6%, 6 and 11% (P = 0.71). In multivariable adjusted analyses, those with CACS >100 were 7.17 times (95% CI: 1.36-37.68) more likely to have ≥2 coronary segments with calcified plaque comparing with CACS 1-10. On the other hand the respective risk was higher for presence of ≥2 segments with mixed plaques (odds ratio: 15.81, 95% CI: 3.14-79.58). Absence of CAC is associated with a negligible presence of any atherosclerotic disease as detected by CCTA in asymptomatic population. A higher CACS is more likely to be associated with heterogeneous coronary plaque (combination of calcified, non-calcified, and mixed plaques), and appears to be more strongly associated with a higher burden of mixed plaque.

Association of traditional cardiovascular risk factors with coronary plaque sub-types assessed by 64-slice computed tomography angiography in a large cohort of asymptomatic subjects

Objective Although prior studies have shown that traditional cardiovascular (CV) risk factors are associated with the burden of coronary atherosclerosis, less is known about the relationship of risk factors with coronary plaque sub-types. Coronary computed tomography angiography (CCTA) allows an assessment of both, total disease burden and plaque characteristics. In this study, we investigate the relationship between traditional CV risk factors and the presence and extent of coronary plaque sub-types in a large group of asymptomatic individuals. Methods The study population consisted of 1015 asymptomatic Korean subjects (53 ± 10 years; 64% were males) free of known CV disease who underwent 64-slice CCTA as part of a health screening evaluation. We analyzed plaque characteristics on a per-segment basis according to the modified American Heart Association classification. Plaques in which calcified tissue occupied more than 50% of the plaque area were classified as calcified (CAP), <50% calcified area as mixed (MCAP), and plaques without any calcium as non-calcified (NCAP). Results A total of 215 (21%) subjects had coronary plaque while 800 (79%) had no identifiable disease. Multivariate regression analysis demonstrated that increased age (per decade) and gender are the strongest predictors for the presence of any coronary plaque or the presence of at least one segment of CAP and MCAP (any plaque—age: OR 2.89; 95% CI 2.34, 3.56; male gender: OR 5.21; 95% CI 3.20, 8.49; CAP—age: OR 2.75; 95% CI 2.12, 3.58; male gender: 4.78; 95% CI 2.48, 9.23; MCAP—age: OR 2.62; 95% CI 2.02, 3.39; male gender: OR 4.15; 95% CI 2.17, 7.94). The strongest predictors for the presence of any NCAP were gender (OR 3.56; 95% CI 1.96–6.55) and diabetes mellitus (OR 2.87; 95% CI 1.63–5.08). When looking at the multivariate association between the presence of ≥2 coronary segments with a plaque sub-type and CV risk factors, male gender was the strongest predictor for CAP (OR 7.31; 95% CI 2.12, 25.20) and MCAP (OR 5.54; 95% CI 1.84, 16.68). Alternatively, smoking was the strongest predictor for the presence of ≥2 coronary segments with NCAP (OR 4.86; 95% CI 1.68, 14.07). Low-density lipoprotein cholesterol (LDL-C) was only a predictor for the presence and extent of mixed coronary plaque. Conclusion Age and gender are overall the strongest predictors of atherosclerosis as assessed by CCTA in this large asymptomatic Korean population and these two risk factors are not particularly associated with a specific coronary plaque sub-type. Smoking is a strong predictor of NCAP, which has been suggested by previous reports as a more vulnerable lesion. Whether a specific plaque sub-type is associated with a worse prognosis is yet to be determined by future prospective studies.

Comparison of 3D Free-Breathing Coronary MR Angiography and 64-MDCT Angiography for Detection of Coronary Stenosis in Patients with High Calcium Scores

The objective of our study was to compare the diagnostic performance of coronary MR angiography (MRA) and 64-MDCT angiography (MDCTA) for the detection of significant stenosis (> or = 50%) in patients with high calcium scores. Eighteen patients (12 men, six women; mean age, 56 y; age range, 38-77 y) who had at least one calcified plaque with a calcium score of > 100 underwent coronary MRA and conventional coronary angiography (CAG) within 2 weeks of MDCTA. Coronary MRA image quality of the calcified segments was assessed by two observers in consensus on a 4-point scale (1 = not visible, 2 = poor, 3 = good, 4 = excellent) using a 10-segment model from the modified American Heart Association classification. Three experienced radiologists, unaware of the results of conventional CAG, independently assessed for the presence of significant stenosis on MDCTA images and the corresponding MRA images. Receiver operating characteristic (ROC) curves were calculated for each reader using conventional CAG as the gold standard. Thirty-three calcified plaques with a calcium score of > 100 were detected on MDCTA in the 18 patients. The coronary segments with nodal calcification (n = 17) showed a higher mean image quality score than the segments with diffuse calcification (n = 16) (3.47 +/- 0.62 vs 2.94 +/- 0.77, respectively; p < 0.05). Of the 33 coronary segments with calcification, 12 significant stenoses were identified on conventional CAG. The sensitivity, specificity, and area under the ROC curve (AUC) for MRA and MDCTA, respectively, were as follows: reader 1, 75%, 81%, 0.82 versus 75%, 48%, 0.68; reader 2, 83%, 71%, 0.82 versus 67%, 52%, 0.63; and reader 3, 83%, 71%, 0.85 versus 83%, 43%, 0.65, respectively. The average AUC of MRA for the three readers was significantly higher than that of MDCTA (p = 0.030). Coronary MRA has higher image quality for coronary segments with nodal calcification than for coronary segments with diffuse calcification. Coronary MRA has better diagnostic performance than coronary MDCTA for the detection of significant stenosis in patients with high calcium scores.

High-Resolution 3 T MR Microscopy Imaging of Arterial Walls

To achieve a high spatial resolution in MR imaging that allows for clear visualization of anatomy and even histology and documentation of plaque morphology in in vitro samples from patients with advanced atherosclerosis. A further objective of our study was to evaluate whether T2-weighted high-resolution MR imaging can provide accurate classification of atherosclerotic plaque according to a modified American Heart Association classification. T2-weighted images of arteries were obtained in 13 in vitro specimens using a 3 T MR unit (Medspec 300 Avance/Bruker, Ettlingen, Germany) combined with a dedicated MR microscopy system. Measurement parameters were: T2-weighted sequences with TR 3.5 sec, TE 15-120 msec; field of view (FOV) 1.4 x 1.4; NEX 8; matrix 192; and slice thickness 600 microm. MR measurements were compared with corresponding histologic sections. We achieved excellent spatial and contrast resolution in all specimens. We found high agreement between MR images and histology with regard to the morphology and extent of intimal proliferations in all but 2 specimens. We could differentiate fibrous caps and calcifications from lipid plaque components based on differences in signal intensity in order to differentiate hard and soft atheromatous plaques. Hard plaques with predominantly intimal calcifications were found in 7 specimens, and soft plaques with a cholesterol/lipid content in 5 cases. In all specimens, hemorrhage or thrombus formation, and fibrotic and hyalinized tissue could be detected on both MR imaging and histopathology. High-resolution, high-field MR imaging of arterial walls demonstrates the morphologic features, volume, and extent of intimal proliferations with high spatial and contrast resolution in in vitro specimens and can differentiate hard and soft plaques.