Coronary Artery Remodeling Research Articles

Coronary and peripheral artery remodeling in patients undergoing PTCA: An intracoronary and transcutaneous ultrasound study.

The aim of this study was to assess the relationship between the plaque burden of nonstenotic coronary artery segments and the wall thickness of peripheral arteries using intracoronary and transcutaneous ultrasound imaging, respectively. Intracoronary ultrasound (CVIS, 3.5 Fr) was performed in 27 patients undergoing percutaneous transluminal coronary angioplasty. Carotid arteries were imaged by B-mode ultrasound with semiautomatic edge detection and radial arteries by high resolution A-mode echotracking (NIUS 2). Quantitative measurements included coronary artery intima-media cross-sectional area (IM(CSA)) and cross-sectional narrowing (CSN), as well as intima-media thickness (IMT) and lumen radius (r) of the common carotid and the radial arteries. Intima-media thickness was increased in coronary, carotid, and radial arteries. Coronary arteries had an IM(CSA) of 7.7 +/- 2.5 mm(2) and a CSN of 24% +/- 8%. Despite this moderate plaque burden, lumen area was preserved (12.3 +/- 4.2 mm(2)) because of compensatory enlargement of coronary arteries. Right and left carotid and right radial arteries had an IMT of 575 +/- 78 microm, 570 +/- 129 microm, and 328 +/- 61 microm, respectively. There was no correlation between coronary IM(CSA) and carotid IMT (r = 0.07) or radial IMT (r = 0.02), and there was no correlation between coronary CSN and carotid IMT/r (r = 0.12), or radial IMT/r (r = 0.25). In conclusion, in these patients with symptomatic ischemic disease no relationship between IMT of the coronary arteries and IMT of carotid or radial arteries was found. Although increasingly popular, IMT of peripheral arteries may be of limited value as surrogate marker for the severity of coronary artery disease. Cathet. Cardiovasc. Intervent. 48:12-17, 1999.

Impact of coronary artery remodeling on misinterpretation of angiographic disease eccentricity: evidence from intravascular ultrasound

This study was designed to examine the impact of coronary artery remodeling, enlargement or shrinkage, on the angiographic disease eccentricity. A total of 82 coronary sites from 73 patients with significant stenosis (>50%) were prospectively analyzed by both quantitative coronary angiography and intravascular ultrasound. By quantitative coronary angiography, the maximal and minimal distances from the center of the stenosis to the outline of the vessel wall were measured, and the eccentricity index was calculated by the formula {(maximal-minimal)/maximal}. By intravascular ultrasound, the maximal and minimal distances from the center of the lumen to the leading edge of the second echogenic zone were measured, and the eccentricity index was calculated by the same formula. For identifying the vessel remodeling, the total vessel area that was determined by tracing the leading edge of the second echogenic zone was measured at the stenotic sites and the adjacent proximal and distal segments. By quantitative coronary angiography, the maximal and minimal distances were 1.76 ± 0.6 and 0.97 ± 0.3 mm, respectively, yielding an eccentricity index of 0.42 ± 0,2. The maximal and minimal distances by intravascular ultrasound were 2.77 ± 0.6 mm and 1.46 ± 0.4 mm, respectively, yielding an eccentricity index of 0.45 ± 0.2 (NS). Although the average eccentricity index was not different between the two methods, there was substantially no correlation between the eccentricity index determined by the two methods ( r = 0.38, y = 0.43 x + 0.22). However, this correlation was significantly improved ( r = 0.55, y = 0.73 x + 0.12, P < 0.001) when 44 stenotic segments with remodeling were excluded for comparison. These results indicate that coronary artery remodeling could be a major contributing factor to angiographic misinterpretation of disease eccentricity. We suggest that intravascular ultrasound is a powerful method that can accurately determine diseases eccentricity as well as disease severity.

Remodeling of atherosclerotic coronary arteries varies in relation to location and composition of plaque

The aim of this study was to determine the contribution of morphologic characteristics and location of plaque in remodeling of atherosclerotic coronary arteries. Consecutive intravascular ultrasound studies performed in native coronary arteries before an intervention were included in the study. Total vessel, lumen and plaque + media areas were measured at target lesion, and distal and proximal references. Remodeling index was calculated as target total vessel area/proximal reference total vessel area, and categorized into 3 groups based on relative total vessel-area ratio: (1) >1.1 (group A, adequate remodeling); (2) 0.9 to 1.1 (group B, failure of compensatory enlargement); and (3) <0.9 (group C, coronary shrinkage). Eighty-nine narrowings were assessed in 80 intravascular ultrasound studies. Thirty-eight lesions (43%) were defined as soft and 51 (57%) as hard. Soft plaques were more prevalent in group A than in groups B and C (p = 0.001). Conversely, the arc of calcium was larger in group C lesions (p = 0.005). At distal segments, group A lesions were more prevalent than those in groups B and C, whereas at proximal segments group C lesions were more prevalent (p = 0.007). Multivariate analysis identified the arc of calcium and the location of plaque at distal segments as independent predictors of compensatory enlargement (odds ratio 0.94, 95% confidence interval 0.90 to 0.99; odds ratio 4.6; 95% confidence interval 1.4 to 15.7, respectively), whereas hard plaques were an independent predictor of coronary shrinkage (odds ratio 4.6; 95% confidence interval 1.7 to 12.5). In conclusion, composition and location of plaque appeared to be major determinants of vessel remodeling during the process of atherosclerosis.

Arterial remodelling of native human coronary arteries in patients with unstable angina pectoris: a prospective intravascular ultrasound study

OBJECTIVETo investigate the use of intravascular ultrasound (IVUS) in detecting the presence of arterial remodelling in patients with unstable angina.DESIGNProspective case study.PATIENTS60 of 95 consecutively admitted patients with unstable angina...

Volumetric remodeling of the proximal left coronary artery: Early versus late after heart transplantation

OBJECTIVESThe aim of this study was to characterize progression of cardiac allograft vasculopathy (CAV) with special respect to coronary artery geometry.BACKGROUNDAs previously shown by intravascular ultrasound (IVUS), CAV is characterized by a multifocal intimal hyperplasia. Little is known, however, about vascular remodeling processes influencing vessel geometry and luminal narrowing.METHODSIn 30 heart transplant recipients serial IVUS studies were performed at baseline (BL) and after a mean follow-up period of 12.5 ± 2.5 months. Changes in plaque, lumen and vessel volume were assessed in the proximal left anterior descending artery. Pattern of remodeling was analyzed in patients “early” (n = 15, BL study 1.4 ± 0.7 months after heart transplantation [HTX]) compared with “late” after HTX (n = 15, BL 46.1 ± 29.1 months).RESULTSPlaque volume was found to increase by a mean of 23.8 ± 25.9 mm3, not significantly different within and beyond the 1st year after HTX. Significant differences, however, were observed in changes in vessel volume with a mean decrease of −52.8 ± 70.9 mm3in the early group, whereas late follow-up group presented with an enlargement of 32.3 ± 46.0 mm3. Based on these changes, lumen volume decreased by −73.2 ± 69.8 mm3early, in contrast to a slight increase of 5.2 ± 32.6 mm3in the late group.CONCLUSIONSProgression of CAV is a complex process, modified by changes in the vascular geometry. Especially within the 1st year after HTX, luminal loss is influenced not only by an increase in plaque area but by a decrease in total vessel volume as well.

Intravascular ultrasonic analysis of plaque characteristics associated with coronary artery remodeling

We sought to determine the patient and plaque characteristics associated with the different forms of arterial remodeling as seen by intravascular ultrasound (IVUS) before coronary intervention. Remodeling in response to plaque accumulation may occur in the form of compensatory enlargement and/or focal vessel contraction. Previous studies report variation in the frequency and form of arterial remodeling. We performed preintervention IVUS imaging on 169 patients. Vessels were categorized as exhibiting compensatory enlargement or focal contraction if the arterial area at the lesion was larger or smaller, respectively, than both proximal and distal reference arterial areas; otherwise the artery was considered not to have undergone significant remodeling. Calcification was assessed and noncalcified plaque density was measured by videodensitometry. Sixty-one of 169 patients (66 narrowings) (46 men and 15 women, age 56 ± 11 years) had adequate reference segments. Remodeling occurred in 43 of 66 patients (65%): compensatory enlargement in 27 of 66 (41%) and focal contraction in 16 of 66 (24%). Lesions with focal contraction had significantly smaller arterial area (13.3 ± 3.3 vs18.1 ± 7.0 mm 2, p = 0.02) and plaque area (9.5 ± 2.8 vs 13.7 ± 5.5 mm 2, p <0.01). Cross-sectional stenosis was similar (71 ± 9% vs 75 ± 10%, p = NS), as was plaque density (p = 0.20), eccentricity, and calcium. Patient age, gender, and lesion location were not related to the form of remodeling. Similarly, history of diabetes, hypercholesterolemia, or hypertension was not predictive. Smoking was the only risk factor associated with focal contraction (p <0.01). Thus, whereas compensatory enlargement appears to be the most common form of coronary artery remodeling, focal contraction occurs more often in smokers.

Mechanisms of coronary artery remodeling in heart transplant recipients. A serial study with intravascular ultrasound and three-dimensional vessel reconstruction: J. Rieber, V. Klauss, C. Weber, F. Prati*, C. H. Spes, C. E. Angermann, B. Reichart, K. Theisen, H. Mudra. Dpt. of Cardiology, Klinikum Innenstadt, University of Munich, Germany, and S. Camillo Hospital*, Rome, Italy

Mechanisms of coronary artery remodeling in heart transplant recipients. A serial study with intravascular ultrasound and three-dimensional vessel reconstruction: J. Rieber, V. Klauss, C. Weber, F. Prati*, C. H. Spes, C. E. Angermann, B. Reichart, K. Theisen, H. Mudra. Dpt. of Cardiology, Klinikum Innenstadt, University of Munich, Germany, and S. Camillo Hospital*, Rome, Italy

Does remodeling occur in the diseased human saphenous vein bypass grafts? An intravascular ultrasound study.

Coronary artery remodeling is a common phenomenon in human atherosclerotic arteries. Controversies exist concerning the presence of absence of the remodeling process in diseased human coronary saphenous vein bypass grafts. The purpose of the study was to observe the vessel and lumen dimensions in patients who had undergone saphenous vein grafting with intravascular ultrasound to find out whether the remodeling process exists in the diseased human saphenous vein bypass grafts. A total of 43 saphenous vein bypass grafts from 43 patients (39 males, 4 females, mean age 63+/-8 years); 1-16 years (mean 9.3+/-4.0 years) after grafting, who had not undergone previous catheter intervention, were studied using intravascular ultrasound. The vessel, lumen and plaque area were measured at the lesion segment as well as in the proximal and distal reference segments. The percent stenosis was calculated. In 43 bypass grafts having severe stenosis before intervention, plaque was eccentric in 69.4% and concentric in 30.6%. No calcification was detected in 75% cases and 25% cases has mild-moderate intimal calcification. The vessel area in the lesion segment was 19.0+/-9.7 mm2, significantly larger than the proximal reference segment 12.8+/-4.0 min2 as well as the distal reference segment 12.9+/-3.6 mm2 (p < 0.001). It was also larger than that of the average area of the proximal and distal reference segments (p < 0.001). The vessel area increased in accordance with plaque area (p < 0.001). A weak relationship existed between vessel area and percent stenosis (r = 0.37, p = 0.04). In contrary to previous findings, diseased human saphenous vein bypass grafts undergo focal compensatory enlargement (remodeling) in the presence of plaque formation. The underlying mechanism is probably similar to that in de novo atherosclerosis.

Coronary artery remodelling and the assessment of stenosis by pathologists.

When atherosclerotic plaques develop, the cross-sectional area of the artery at that point often increases to accommodate the plaque without any reduction in lumen size. In consequence the angiogram does not detect a high proportion of atherosclerotic plaques. The increase in size of the artery (compensatory dilatation-arterial remodelling) varies widely in degree between different plaques even in the same artery. Dilatation of a degree to prevent any loss of lumen size is regarded as adequate compensatory dilatation. In contrast, other plaques are associated with no or minimal increase in the vessel cross-sectional area and a reduction in lumen size in present (inadequate compensation). High-grade stenosis is in particular associated with a total failure of remodelling. Such plaques may have had a rapid growth phase, out-pacing the ability of the medial smooth muscle cells to undergo a rearrangement. The phenomenon of remodelling has important consequences for pathologists who use the traditional method of comparing the lumen size relative to the cross-sectional area of the vessel at the site of a plaque to measure stenosis. The area of the vessel at this point may be anything up to 60% above its size before the plaque developed. An error is introduced which on average overestimates diameter stenosis by 30% when compared to an angiographic equivalent method in which the lumen size at the lesion is compared to the lumen size at an adjacent segment of artery without a plaque.

How Should We Define Inadequate Coronary Arterial Remodeling?

To the Editor: After our report1 showing the contribution of “inadequate compensatory enlargement” to the development of coronary narrowing, Mintz et al2 in their recently published report confirmed this concept in a larger study population by using a different definition of “inadequate arterial remodeling.” However, the assessment of the relative importance of “inadequate arterial remodeling” is highly dependent on the definition used. As pointed out by Mintz et al, the assessment of the true effect of vessel remodeling on the progression of coronary narrowing would require serial or longitudinal intravascular ultrasound studies (IVUS) over a long time period. However, such longitudinal, serial studies are time consuming and impractical. Consequently, we compared the size of the external elastic lamina (EEL) area (the area within the outer border of the sonolucent zone considered to represent EEL) at the lesion site with those at the reference sites. The proximal and distal reference sites were defined as the sites with minimal narrowing by angiography and the largest lumen area and <50% area stenosis as determined by IVUS. In our study,1 the EEL area of all arteries was larger at the proximal reference sites than at the distal reference sites, and “inadequate compensatory enlargement” was defined …

Mechanism of luminal narrowing in cardiac allograft vasculopathy: Inadequate vascular remodeling rather than intimal hyperplasia is the major predictor of coronary artery stenosis

Background: Despite increasing knowledge about degree and distribution pattern of intimal hyperplasia in cardiac allograft vasculopathy, coronary artery remodeling is only poorly understood in this disease. Methods: To evaluate vascular geometry, intravascular ultrasound was used to characterize 57 advanced lesions in 35 consecutive transplant recipients. Lumen, plaque, and vessel area in these target lesions were compared with proximal and distal reference sites. Results and Conclusions: Vascular remodeling by compensatory local vessel enlargement (positive remodeling) and circumscript vascular constriction (negative remodeling) could be demonstrated. Plaque area in stenotic lesions was significantly increased compared with the mean reference site (5.6 ± 3.0 mm 2 versus 2.8 ± 1.5 mm 2, p < 0.001); however, inadequate compensatory enlargement rather than intimal hyperplasia was shown to be the most important predictor of luminal obstruction ( r = 0.77, p < 0.001). (Am Heart J 1998;135:628-33.)

Coronary Artery Remodeling After Acute Myocardial Infarction

Coronary Artery Remodeling After Acute Myocardial Infarction

Impact of Coronary Artery Remodeling on Angiographic Misinterpretation of Disease Eccentricity: Evidence From Intravascular Ultrasound

Impact of Coronary Artery Remodeling on Angiographic Misinterpretation of Disease Eccentricity: Evidence From Intravascular Ultrasound

Impact of coronary artery remodeling on angiographic misinterpretation of disease eccentricity: evidence from intravascular ultrasound

Impact of coronary artery remodeling on angiographic misinterpretation of disease eccentricity: evidence from intravascular ultrasound

Evaluation of endothelial shear stress and 3D geometry as factors determining the development of atherosclerosis and remodeling in human coronary arteries in vivo. Combining 3D reconstruction from angiography and IVUS (ANGUS) with computational fluid dynamics.

The predilection sites of atherosclerotic plaques implicate rheologic factors like shear stress underlying the genesis of atherosclerosis. Presently no technique is available that enables one to provide 3D shear stress data in human coronary arteries in vivo. In this study, we describe a novel technique that uses a recently developed 3D reconstruction technique to calculate shear stress on the endothelium with computational fluid dynamics. In addition, we calculated local wall thickness, the principal plane of curvature, and the location of plaque with reference to this plane, relating these results to shear stress in a human right coronary artery in vivo. Wall thickness and shear stress values for the entire vessel for three inflow-velocity values (10 cm/second, 20 cm/second, and 30 cm/second equivalents with the Reynolds numbers 114,229, and 457) were as follows: 0.65 +/- 0.37 mm (n = 1600) and 19.6 +/- 1.7 dyne/cm2; 46.1 +/- 8.1 dyne/cm2 and 80.1 +/- 16.8 dyne/cm2 (n = 1600). Curvature was 25 +/- 9 (m-1), resulting in Dean numbers 20 +/- 8; 46 +/- 16, and 93 +/- 33. Selection of data at the inner curvature of the right coronary artery provided wall thickness values of 0.90 +/- 0.41 mm (n = 100), and shear stress was 17 +/- 17, 38 +/- 44, and 77 +/- 54 dyne/cm2 (n = 100), whereas wall thickness values at the outer curve were 0.37 +/- 0.17 mm (n = 100) and shear stress values were 22 +/- 17, 60 +/- 44, and 107 +/- 79 dyne/cm2 (n = 100). These findings could be reconciled by an inverse relationship between wall thickness and shear stress for each velocity level under study. For the first time for human vessels in vivo, evidence is presented that low shear stress promotes atherosclerosis. As the method is nondestructive, it allows repeated measurements in the same patient and will provide new insights in the progress of atherosclerosis.

Remodeling of human coronary arteries undergoing coronary angioplasty or atherectomy.

Recently, long-term constriction of the vessel has been suggested as an alternative mechanism of restenosis after coronary angioplasty. To understand remodeling of human coronary arteries undergoing coronary angioplasty or atherectomy, serial intravascular ultrasonographic examinations were performed at preintervention and postintervention examinations and at 24 hours, 1 month, and 6 months. Complete serial data were obtained in 61 lesions (balloon angioplasty, 35 lesions; directional atherectomy, 26 lesions). Lumen area improved from 6.81+/-2.24 mm2 after intervention to 8.22+/-2.79 mm2 at 1 month (P=.0001) and decreased to 4.88+/-2.86 mm2 at 6 months (P=.0001). Vessel area enlarged from 17.32+/-5.35 mm2 after intervention to 19.39+/-5.33 mm2 at 1 month (P=.0001) and decreased to 16.33+/-5.54 mm2 at 6 months (P=.0001). Plaque+media area increased significantly from postintervention examination to 24 hours (10.51+/-4.38 versus 10.96+/-4.49 mm2, P=.0008) and from 24 hours to 6 months (10.96+/-4.49 versus 11.45+/-4.45 mm2, P=.03). Changes in lumen area in each study interval correlated more closely with changes in vessel area than with changes in plaque+media area. Restenotic lesions compared with nonrestenotic lesions had a greater decrease in the vessel area between 1 month and 6 months (-4.33+/-2.73 versus -2.49+/-2.15 mm2, P=.006) and greater increase in the plaque+media area both within 24 hours (0.84+/-1.22 versus 0.27+/-0.38 mm2, P=.04) and between 24 hours and 6 months (1.19+/-2.19 versus 0.18+/-1.46 mm2, P=.04). CONCLUSIONS; Remodeling after coronary angioplasty or atherectomy was characterized by early adaptive enlargement and late constriction of the vessel.

Remodeling of atherosclerotic coronary arteries assessed with intravascular ultrasound in vitro

Regression analysis of vessel area on plaque area measured in different arteries is unable to discern different patterns of remodeling in vessels. Analyses that compare a target site with a reference site have limitations related to the choice of these sites. An adequate method to analyze the impact of progression of atherosclerosis on vessel area should entail a longitudinal study of a vessel segment over time.13

Coronary artery and saphenous vein graft remodeling: a review of histologic findings after various interventional procedures--Part V.

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effect on the site of obstruction has been termed "remodeling." Part V of this six-part series focuses on remodeling effects of balloon angioplasty on obstructed young (< or = 1 year) and old (> 1 year) saphenous vein bypass grafts.

Coronary artery and saphenous vein graft remodeling: a review of histologic findings after various interventional procedures--Part IV.

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed "remodeling." Part IV of this six-part series focuses on morphologic correlates of coronary angiographic patterns of remodeling after balloon angioplasty and discusses effects of angioplasty on adjacent, nondilated vessels.

Coronary artery and saphenous vein graft remodeling: A review of histologic findings after various interventional procedures--Part III.

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed "remodeling." Part III of this six-part series focuses on intimal proliferation and chronic recoil in patients undergoing previous remodeling techniques by balloon angioplasty.