Novel insights into coronary lumen preservation during progression of coronary atherosclerosis in coronary atherosclerosis-prone rabbits

BACKGROUND: In coronary atherosclerosis-prone Watanabe heritable hyperlipidaemic (WHHLCA) rabbits, an animal model for low-density lipoprotein receptor deficiency and spontaneous coronary atherosclerosis, the coronary arteries show compensatory remodelling during the progression of atherosclerosis. Therefore, we analysed coronary remodelling of WHHLCA rabbits quantitatively using a method that eliminates the limitations of previous analytical methods. METHODS: Arterial remodelling was evaluated in perfusion-fixed coronary arteries of 11 WHHLCA rabbits using both new and previous analyses. With the improved methods removing limitations on quantitative analysis of arterial remodelling, we evaluated how lumen area or arterial size changed with accumulating atherosclerotic plaques compared to before plaque development. The original lumen area before plaque development was calculated using the diameter-length relationship. Wall shear stress change ratio was calculated from changes in arterial size. RESULTS: Using the old analytical method (and as seen in similar human studies), lumen area increased up to a level of 29% of cross-sectional narrowing. However, with the improved analysis, in cross-sectioning narrowing at levels below 10%, the lumen area modestly decreased, and when the cross-sectional narrowing ranged from 10-68%, the lumen area remained constant, and diminished sharply despite continued remodelling when cross-sectional narrowing reached 70% or above. Arterial remodelling progressed quantitatively to a slight increase in arterial wall shear stress as well as lumen area up to a level of 70% cross-sectional narrowing. CONCLUSIONS: These findings demonstrate marked influences of arterial tapering and individual variation of arterial size on quantitative analysis of arterial remodelling, and provide the novel insight that coronary compensatory remodelling in atherosclerosis maintains the lumen size up to levels of 70% cross-sectional narrowing in proportion to wall shear stress.     

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.     

Contribution of inadequate compensatory enlargement to development of human coronary artery stenosis: An in vivo intravascular ultrasound study

Objectives. This intravascular ultrasound study sought to examine to what extent native coronary artery stenosis is accompanied by vessel wall thickening or inadequate compensatory enlargement (relative vessel constriction), or both.

Background. In human femoral arteries, inadequate compensatory enlargement is reported to be a paradoxic mechanism for the development of severe arterial lumen narrowing. However, it is unclear in human coronary arteries whether inadequate compensatory enlargement contributes to the development of critical arterial stenosis.

Methods. Thirty-five primary coronary artery lesions from 30 patients (19 men, 11 women; mean [±SD] age 65 ± 13 years) were imaged by intravascular ultrasound. The vessel cross-sectional area and lumen area were measured, and the wall area (vessel cross-sectional area minus lumen area) was calculated at the lesion site and at the proximal and distal reference sites. We defined compensatory enlargement to be present when the vessel cross-sectional area at the lesion site was larger than that at the proximal reference site, inadequate compensatory enlargement when the vessel cross-sectional area at the lession site was smaller than that at the distal reference site and intermediate remodelling when the vessel cross-sectional area at the lesion site was intermediate between the two reference sites.

Results. Compensatory enlargement was observed in 19 (54%) of 35 lesions, inadequate compensatory enlargement in 9 (25%) of 35 and intermediate remodeling in 7 (20%) of 35. In the inadequate compensatory enlargement group, reduction of the vessel cross-sectional area contributed to 39% of lumen reduction.

Conclusions. Compensatory enlargement commonly (54%) occurs at stenotic coronary lesions. However, inadequate compensatory enlargement results in a substantial amount (39%) of the lumen area reduction in 26% of primary coronary artery lesions.     

Quantitative Morphologie der Koronararterien in der zweiten und dritten Lebensdekade

1. In 8 cases in the second decade and 10 cases in the third decade without coronary sclerosis and 5 cases with early sclerosis quantitative measurements were made on graded sections of the coronary arteries which were fixed in toto by compression. The surfaces of the lumen, intima and media were determined planimetrically and the thickness of the intima and media and the radius of the lumen of the three main branches of the coronary arteries were determined micrometrically. A post-mortem coronary angiogram was made of each heart and the connective tissue content of the right and left heart was determined planimetrically. 2. Higher values are found in the absolute measurements of surface and thickness of each cross-section in the third decade than in the second. In both age groups the anterior descending ramus is predominant in all criteria. About the end of the second decade the intima attains the thickness of the media and shows the greatest variability of all parameters, especially in the second decade. In both decades the media plays an equally important role in growth as the intima. In the anterior descending ramus the intima has a higher percentage growth rate than in the right coronary artery and in the left ramus circumflexus. In the third decade it has reached a mean thickness of 122 mu in the initial part of the anterior descending ramus and a mean surface area of 1.18 mm2. In the same area the mean thickness of the media also in the third decade, would be 124 mu, and the mean surface area of the media 1.64 mm2. 3. The indices of coronary sclerosis and coronary insufficiency were determined by the method of Freudenberg, Knieriem, M?ller and Janzen (1974). Using the mean values for the second and third decades and calculating the regression in the fourth to seventh decades, we found as upper normal limits a coronary sclerosis index of I = 0.3 for hearts without coronary sclerosis, for the coronary sclerosis index II = 0.6, for the coronary insufficiency index I = 0.3, for the coronary insufficiency index II = 0.6 and for the coronary insufficiency index III = 1.0.     

Reproducibility of coronary lumen, plaque, and vessel wall reconstruction and of endothelial shear stress measurements in vivo in humans.

The purpose of this study was to assess the reproducibility of an in vivo methodology to reconstruct the lumen, plaque, and external elastic membrane (EEM) of coronary arteries and estimate endothelial shear stress (ESS). Ten coronary arteries without significant stenoses (five native and five stented arteries) were investigated. The 3D lumen and EEM boundaries of each coronary artery were determined by fusing end-diastolic intravascular ultrasound images with biplane coronary angiograms. Coronary flow was measured. Computational fluid dynamics was used to calculate local ESS. Complete data acquisition was then repeated. Analysis was performed on each data set in a blinded manner. The intertest correlation coefficients for all arteries for the two measurements of lumen radius, EEM radius, plaque thickness, and ESS were r = 0.96, 0.96, 0.94, 0.91, respectively (all P values < 0.0001). The 3D anatomy and ESS of human coronary arteries can be reproducibly estimated in vivo. This methodology provides a tool to examine the effect of ESS on atherogenesis, remodeling, and restenosis; the contribution of arterial remodeling and plaque growth to changes in the lumen; and the impact of new therapies.     

Coronary arterial remodeling studied by high-frequency epicardial echocardiography: an early compensatory mechanism in patients with obstructive coronary atherosclerosis

Coronary arterial remodeling is a compensatory mechanism that may limit the adverse effects of coronary obstructive lesions by expansion of the entire vascular segment. To determine if this compensatory anatomic change occurs in patients, high-frequency epicardial echocardiography using a 12 MHz transducer was performed during open heart surgery in 33 patients (10 with normal coronary arteries undergoing valvular surgery and 23 with coronary atherosclerosis). From stop-frame videotape high-frequency epicardial echocardiographic images, cross-sectional measurements of luminal area and total arterial area (lumen, intima, media and dense adventitia) were made in the patients with atherosclerosis at the site of arterial lesions and from the most proximal portion of the same artery. Remodeling was defined as enlargement of the total arterial area. In normal arteries measurements were made from proximal and midarterial locations. In the patients with normal coronary arteries, total arterial area, as determined by high-frequency echocardiography, decreased from the proximal site to the midportion of the artery (from 10.4 +/- 0.9 to 8.4 +/- 1.0 mm2, p less than 0.05); luminal area also decreased (from 6.0 +/- 0.6 to 4.5 +/- 0.7 mm2, p less than 0.05). In patients with coronary arterial lesions, luminal area also decreased from the proximal site to the arterial lesion site (from 5.3 +/- 0.6 to 2.3 +/- 0.3 mm2, p less than 0.05), but total arterial area increased (from 11.6 +/- 1.0 to 13.0 +/- 1.0 mm2, p less than 0.05). Of the 25 coronary arteries evaluated, only 4 had angiographic evidence of coronary collateral formation. These data indicate that coronary arterial remodeling is an important compensatory mechanism in obstructive coronary disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Natural course of supravalvar aortic stenosis and peripheral pulmonary arterial stenosis in Williams' syndrome.

We investigated the catheterization and angiographic findings of 26 patients with Williams' syndrome to evaluate the natural course of supravalvar aortic stenosis and peripheral pulmonary arterial stenosis. The severity of the stenosis was correlated with age and body surface area in terms of the pulmonary arterial index, right ventricular systolic pressure, sinutubular ratio (ratio of measured to mean normal diameter of sinutubular junction), and systolic pressure gradient across the sinutubular junction. In patients with pulmonary arterial stenosis (n=20), right ventricular systolic pressure tended to decrease, and pulmonary arterial index increased, with increase in age and body surface area. Between the groups with and without pulmonary arterial stenosis, there was significant difference in age (mean 4.70 vs. 9.87, p=0.019), body surface area (0.62 vs. 1.16, p=0.002), pulmonary arterial index (152 vs. 317, p=0.002) and right ventricular systolic pressure (73.9 vs. 33.0, p=0.006). As all patients showed similar diameters at the sinutubular junction regardless of age and body size, sinutubular ratio decreased with increases in age and body surface area. The group with abnormal coronary arteries (n=7) had smaller sinutubular ratio (0.46 vs. 0.61, p=0.021) and higher pressure gradients between the left ventricle and the aorta (67.6 vs. 42.2, p=0.023) than did the group with normal coronary arteries. Stenosis of a coronary artery, or a branch of the aortic arch, was observed only in three patients with diffuse aortic stenosis. Our results suggest that, with time, peripheral pulmonary arterial stenosis tends to improve, and supravalvar aortic stenosis to progress. Failure of growth of the sinutubular junction might be responsible for the progression of the aortic lesion. Progression of the aortic lesion may be associated with involvement of the coronary arteries.     

The relation of coronary and peripheral arterial disease to the severity of femoral atherosclerosis in hypercholesterolaemia

Abstract. Objectives. The extent of atherosclerosis in the superficial femoral artery and the severity of arterial disease in the aorto-iliac and femoro-popliteal arterial districts were related to clinical diagnosis of coronary and peripheral atherosclerosis in hypercholesterolaemic patients. Design. The study constitutes baseline cross-sectional data of a randomized double-blind clinical trial on Probucol, using both computer based and visual estimations of angiographies as endpoints. Subjects. Two hundred and ninety men and women (mean age 54 years) with hypercholesterolaemia. Main outcome measures. Atherosclerosis was estimated with arteriographies. Lumen volume and edge roughness (vessel inner wall irregularity) of a 20 cm segment of the femoral artery were estimated by computer. A visual atherosclerosis score of the abdominal aorta to the popliteal arteries was made on both sides. Results. Patients with peripheral arterial disease had significantly more advanced disease according to all three angiographic variables than those without symptoms of peripheral vascular disease. Both men and women with coronary artery disease had significantly lower femoral lumen volume and higher roughness values than patients without. Men with previous myocardial infarction had significantly higher mean visual scores of atherosclerosis than those without, while lumen volume and roughness did not differ in either sex. Conclusions. Femoral atherosclerosis is an expression of a generalized disease, associated with clinical symptoms of coronary artery disease. Femoral atherosclerosis is often accompanied by atherosclerosis also in the coronary arteries.     

Infection-associated intimal thickening in the coronary arteries of children

OBJECTIVES: based on autopsy material from children this study investigated the possible relationship of clinically evident infection prior to death with intimal thickening of the coronary arteries. BACKGROUND: viral infections are suggested to be associated with intimal thickening in the coronary arteries both in animals and man. METHODS: the coronary arteries were examined in 175 autopsied children 0-15 years of age (median 7 days). Semi-serial cross sections of the coronary arteries were screened for maximal intimal thickening at 0.2 mm intervals. The length of the internal elastic lamina, the areas of arterial media and intima were measured from cross-sections. Irregular linings of the arteries were mathematically transformed to circles. The percentage of intimal and musculoelastic layer area to luminal area encircled by arterial media was calculated. RESULTS: intimal thickening increased with age but was also associated with the presence of infectious disease at death. Already in the newborn children, who died shortly after the birth, the percentage of intimal and musculoelastic layer area to luminal area encircled by arterial media was big, maximally 55%. In the left coronary artery the mean percentages were 32 and 21% in the groups with viral and bacterial infections, respectively as compared to 16% in the group with no evidence of infection. CONCLUSION: infections in general and viral infections in particular, seem to be associated with intimal thickening, which may predispose coronary arteries to atherosclerosis. Atherogenesis might have a rapid dynamic component.     

Sex differences in coronary atherosclerosis: coronary angiography and intravascular ultrasonography

OBJECTIVES: Women have higher mortality and frequency of complications compared with men after coronary intervention. Possible differences in coronary atherosclerosis between men and women were investigated. METHODS: The left anterior descending arteries of 214 patients (164 men, mean age 62.3 +/- 9.10 years; 50 women, mean age 67.8 +/- 7.76 years) were examined. Lesion length, reference diameter, percentage diameter stenosis and minimal lumen diameter were measured by quantitative coronary angiography. Vessel area, lumen area, percentage area stenosis, and remodeling index were measured by intravascular ultrasonography, and presence of calcification in the lesion was classified. These parameters were compared between men and women. RESULTS: There were no significant differences in quantitative coronary angiography, but intravascular ultrasonography showed calcification was more severe in women, vessel area was significantly smaller in women (13.25 +/- 4.21 vs 15.91 +/- 4.35 mm2, p = 0.004), and remodeling index was significantly lower in women (0.95 +/- 0.13 vs 1.04 +/- 0.18, p = 0.015). CONCLUSIONS: Vessel area measured by intravascular ultrasonography was significantly smaller in women, and calcification was more severe in women. Such factors may be involved in the higher mortality in women.     

What have we learned about coronary artery disease from high-frequency epicardial echocardiography?

We have used a high frequency epicardial echocardiographic technique to visualize and measure coronary artery lumens and walls in patients undergoing cardiac surgery. A 12 MHz probe (Surgiscan, Biosound Corp.) is sterilized and placed on the exposed epicardial coronary arteries. Transverse cross-sectional views are obtained from the arteries on the anterior surface of the heart: the right coronary artery to the cardiac margin and the left anterior descending coronary artery to the cardiac apex.Numerous echocardiographic-angiographic-pathological correlations have been obtained from this work. We have validated the echocardiographic lumen and wall measurements by comparing the echo measurements to histological material from pressure-distended coronary arterial segments (from animals and fresh human autopsy specimens). We have shown by comparison with angiography that coronary arteries which appear normal or only minimally diseased by angiograms are often diffusely and severely atherosclerotic. We have also evaluated the shape of atherosclerotic lesions and demonstrated a wide range of lumen shapes (oval, circular, complex) and location within the residual coronary lumen (eccentric vs. concentric). Highly eccentric lesions are characterized by relative preservation of portions of the arterial wall, and this may preserve vasoreactivity of the atherosclerotic vessel. We have also demonstrated remodeling of atherosclerotic lesions: enlargement of the total arterial area (wall plus lumen) as a compensatory mechanism to preserve the arterial lumen in the face of encroaching atherosclerosis.High frequency epicardial echocardiography offers an accurate, real-time, in-vivo method for the anatomic and functional evaluation of coronary atherosclerosis. This dynamic, in-vivo technique supports and extends information previously obtainable only from pathologic studies. It contributes to our understanding of the pathologic anatomy of coronary artery disease.     

Age-associated changes in mesenteric arteries.

Vascular disease increases in incidence with age and is the commonest cause of morbidity and mortality among elderly people. Hypertension is associated with hypertrophy of the arterial media. This study was designed to investigate changes in arterial structure that may occur with age independent of blood pressure. Collapsed sections of human mesenteric arteries (external diameter 2-3 mm) were measured using a semi-automatic image analysis system. There was a nonlinear increase in both the wall/lumen area ratio and the relative intimal area with age. There were no significant relationships between blood pressure and either the wall/lumen ratio or the relative intimal area.     

In vitro and in vivo intravascular ultrasound imaging.

This paper presents our experience with intravascular ultrasound imaging of animal and human arteries in vitro and in vivo using a high-frequency (20 M Hz) ultrasound transducer. In vitro, 32 human coronary artery segments were imaged with intravascular ultrasound and compared with corresponding histological sections. Ultrasound and histology measurements correlated significantly (P less than 0.0001) for coronary artery cross-sectional area (r = 0.94), lumen cross-sectional area (r = 0.85) and wall thickness (r = 0.92). In vivo, 19 sheep and eight human common femoral arteries were imaged and the angiographic lumen diameter of 14 animal and six human arteries was compared to the diameter of the corresponding ultrasound images. Significant correlations were found for lumen diameter in animals and humans (P less than 0.001, r = 0.91 and P less than 0.0001, r = 0.96, respectively). These studies demonstrate that this technique can provide high resolution images of arterial vessels and may have unique advantages in diagnosing atherosclerotic vascular disease and in catheter based therapies.     

Hyperplasia of coronary intima in young males in relation to development of coronary heart disease in adults

The aim of the investigation was to study structural features of coronary arteries in young males which may influence the development of stenosing coronary atherosclerosis in older age. We studied the coronary arteries from 84 males, 10-39 years old, who died from accidents in Moscow, Malmo and Riga, and 98 males aged 40 and above from Moscow who died from coronary heart disease (71 cases) or other diseases (27 cases). In children and young males from all three cities, musculo-elastic hyperplasia of the coronary intima took place constantly but with different degrees of expression; a strict relationship of the intimal thickness and age was observed. Histometric investigations of the right coronary artery showed that in young males of Riga, in comparison with those of Malmo, the intima was significantly thicker both outside (69.6+/-2.8 and 58. 2+/-2.5 microm) and within the area of cushion like thickening (118. 8+/-4.0 and 101.9+/-3.8 microm), they had more extended cushion-like thickening of intima (42.6+/-3.0 and 30.8+/-3.3% to the length of the artery circumference) and destroyed parts of the internal elastic lamina (28.3+/-1.9 and 19.1+/-1.7% of its length). In males older than 40 years, severe coronary atherosclerosis and stenosis was also significantly more common in Riga than in Malmo. Our data indicate that with age the intimal musculo-elastic hyperplasia in the coronary arteries is transformed to a fibro-elastic layer. The thickness of this layer in the presence of stenosing plaques (>75% of arterial lumen) was much greater than in the presence of plaques with stenoses less than 50% (188.1+/- 7.3 and 69.8+/-4.5 microm, respectively). CONCLUSION: The development of stenosing coronary atherosclerosis is closely related to the degree of musculo-elastic intimal hyperplasia in childhood and young age. The formation of a fibro-elastic layer in the coronary intima decreases the ability of the artery to dilate during the development of atherosclerosis.     

Coronary artery diameters in infants and children with congenital heart disease as determined by computed tomography

This study was conducted to establish reference curves and formulas for the diameters of the coronary arteries in infants and children using computed tomography. A total of 145 children (57 female, 88 male) ranging in age from 2 days to 19 years, 11 months (mean 5 years, 10 months), were retrospectively identified, and the diameters of their coronary arteries were quantified. The measurability of the coronary arteries, coronary arterial size differences between the genders, and relations of the diameters of the coronary arteries to age, height, weight, body surface area, and the diameter of the descending aorta were examined. Independent-samples Student's t tests, 2-tailed Pearson's correlations, and linear regression were used in statistical analysis. The measurability of all coronary arteries was 73.3%. No difference in coronary arterial size was found between the genders. The diameter of the descending aorta correlated most strongly with coronary arterial size. In conclusion, predictive formulas and reference curves for coronary arterial diameters in infants and children were obtained.     

Long-term histologic patency after percutaneous transluminal coronary angioplasty is predicted by the creation of a greater lumen area

Objectives. This study assessed the relation between histologic acute and long-term lumen size after coronary angioplasty.Background. Angiographic studies suggest that the creation of a larger acute lmmen is associated with a reduced incidence of restenosis. Histologic evaluation of the influence of the acute lumen on late outcome has not been previously reported.Methods. Detailed histologic examination and planimetry were performed in 28 postmortem coronary arteries subjected to angioplasty at an average of 71 weeks antemortem. The lumen area on each histologic segment was defined as the final lumen area. The lumen area immediately after angioplasty, the acute lumen area, was deined by the sum of the neointimal area plus final lumen. A final lumen area ≥ 25% of the arterial area was considered a long-term success; a final lumen area < 25% was considered a long-term failure.Results. Arterial size and neointimal area were similar in long-term successes aid failures. In successes, the mean (±SD) acute lumen area was greater than in failures (4.1 ± 1.9 vs. 2.7 ± 1.4 mm², respectively, p < 0.001). The acute lumen area as a percent of arterial area was 46 ± 10% in successes versus 27 ± 11% in failures (p < 0.0001). The corresponding estimated mean acute lumen diameter stenosis was 24 ± 8% in successes versus 42 ± 12% in failures (p < 0.0001). Plaque area was greater in failures (7.1 ± 3.2 mm²) than in successes (4.8 ± 2.4 mm², p < 0.002).Conclusions. Neointimal proliferation after angioplasty occurs in all dilated coronary arteries, and the amount of neointimal growth is independent of vessel size. The creation of a larger lumen and a larger lumen as a percent of vessel size were associated with an improved long-term histologic patency.     

Intravascular ultrasound assessment of ambiguous coronary lesions

Accurate assessment of coronary lesions is essential for clinical decision-making. While angiography has long been accepted as the gold standard investigation, this technique provides only a planar 2-D silhouette of the arterial lumen and therefore has limited accuracy in the setting of vessel tortuosity or overlap, bifurcational and eccentric lesions, and diffusely diseased arteries. By providing high-resolution cross-sectional imaging through the arterial wall, intravascular ultrasound (IVUS) can overcome many of these limitations and accurately quantify angiographically indeterminate lesions. Angiographic evaluation of the left main coronary artery presents particular challenges that are ideally resolved with IVUS examination. The role of IVUS in the assessment of coronary stenoses of angiographically intermediate severity (50-70%) continues to evolve. Recent data correlating IVUS with intracoronary flow and pressure measurements suggest that epicardial coronary artery lesions with minimum lumen area of less than 3-4 mm2 may be haemodynamically significant. In addition to accurately quantifying minimum lumen diameter and area at the lesion site, IVUS can characterise coronary artery plaque morphology, and it may have the potential to predict plaque complications.     

Advancing age is associated with diminished vascular remodeling and impaired vasodilation in resistance coronary arteries

BACKGROUND: Compensatory enlargement of the coronary arterial wall has been described in the early stages of native atherosclerosis. However, little is known about the specific effect of aging on this adaptive process in atherosclerosis. The purpose of the current study was to characterize the effects of advancing age on vascular remodeling and endothelium-dependent and -independent coronary vasodilation in patients without coronary artery disease risk factors. METHODS: Twenty-six patients without coronary risk factors and with normal and mildly diseased coronary arteries were studied. Vessel, lumen and atherosclerotic plaque areas were evaluated by intravascular ultrasound and coronary flow response was assessed using papaverine and acetylcholine in the left anterior descending coronary artery. RESULTS: There was a weak but significant correlation between plaque area and age (r = 0.29, P<0.01). Vessel area was also weakly but significantly correlated with age (r = 0.22, P<0.05). However, lumen area had no correlation with age. Vessel area in the younger group (<50 years) and the older group (> or =50 years) increased 1.64 and 0.55 mm2 for every 1 mm2 increase in plaque area (r = 0.62, P<0.0001 and r = 0.39, P<0.05, respectively). With regard to vascular reactivity, there was an inverse correlation between the percentage increases in coronary blood flow (CBF) evoked by acetylcholine and aging (r = -0.49, P<0.05). The percentage increases in CBF evoked by papaverine also inversely correlated with aging (r=-0.53, P<0.01). However, the percentage changes in coronary artery diameter evoked with acetylcholine did not correlate with aging. CONCLUSION: This study suggests that endothelium-dependent and -independent vasodilation of the resistance coronary artery are impaired with advancing age, which may be in association with attenuated coronary vascular remodeling with aging.     

Percutaneous perfusion of occluded coronary arteries with blood from the femoral artery: a dog study

The idea of perfusing the distal coronary artery with arterial blood during balloon dilatation was implemented in early experimental coronary angioplasty but then abandoned. We pursued this concept in an animal model using a specially designed roller pump. The pump delivers blood from a femoral artery catheter through the central lumen of a balloon catheter occluding a coronary artery. Perfusion of large proximally occluded coronary arteries for at least 60 min was possible in 8 of 11 heparinized dogs. Hemolysis occurring in the pump system due to the small catheter lumen proved a minor problem. For a limited period of time, occluded coronary arteries can be adequately perfused with arterial blood by this percutaneous system that is readily applicable in any catheterization laboratory. Its use is conceivable not only for temporary treatment of acute complications during angioplasty but also for prolonged balloon dilatations of spastic or thrombosed coronary arteries.     

The extramural and intramural coronary arteries in juvenile diabetes mellitus: analysis of nine necropsy patients aged 19 to 38 years with onset of diabetes before age 15 years

This report describes the status of the coronary arteries in nine patients (average age, 29 years) with juvenile onset diabetes mellitus (average age at onset, nine years), and compares the clinical and morphologic observations in them to those in nine control subjects (average age, 29 years). The nine patients with juvenile diabetes had significantly more extramural coronary luminal narrowing by atherosclerotic plaques than did the control subjects. The lumens of one or more of the four major epicardial coronary arteries were narrowed more than 75 per cent in cross-sectioned area in six of the diabetic patients and in none of the control subjects. This difference in degree of narrowing of the epicardial coronary arteries was even more striking when the per cent of narrowing of the entire lengths of the four major coronary arteries was examined: of the 191 cm of major coronary artery examined in the nine diabetic patients, the lumen in 90.5 cm (47 per cent) was narrowed more than 50 per cent in cross-sectioned area, whereas of 155 cm of coronary artery examined in the nine control subjects, the lumen of only 2 cm (1 per cent) was narrowed to this degree.Minor degrees of intimal fibrous proliferation, considered of no functional consequence, were observed in the intramural coronary arteries in the ventricles (excluding papillary muscle) in six of the nine diabetic patients but in none of the nine control subjects. Periodic acid-Schiff-positive material was more frequent and of greater intensity in the diabetic patients (all nine) than in the control subjects (four of nine).