Tim Crowe

This book presents a comprehensive overview of the major approaches to the imaging of the coronary arteries. These modalities, which include traditional angiography as well as intravascular and non-invasive imaging techniques, are used to diagnose and quantify the extent of obstructive disease due to atherosclerosis. Featuring contributions from le...

The aim of this study was to evaluate the progression of atherosclerosis within the left main coronary artery (LMCA) in association with risk factor modifying therapies. Despite studies demonstrating slowing of disease progression within epicardial coronaries with risk factor modification, little is known about the natural history and clinical sequ...

Atherosclerotic cardiovascular disease is a leading cause of morbidity and mortality despite the widespread use of established medical therapies. This has prompted the search to identify new therapeutic approaches to achieve more effective prevention of cardiovascular events. Considerable interest has focused on the role of surrogate markers of the...

We investigated attenuated plaque (hypoechoic plaque with deep ultrasonic attenuation despite absence of bright calcium) in nonculprit lesions. Recent intravascular ultrasound (IVUS) studies describe acoustic shadowing behind large, echolucent, acute culprit lesion sites in the absence of bright calcium. Such "attenuated plaque" is considered a cha...

We investigated coronary atheroma progression in patients with low levels of low-density lipoprotein cholesterol (LDL-C) and systolic blood pressure (SBP). Low LDL-C and SBP beneficially impact coronary atherosclerosis. However, the association between intensive control of both risk factors and coronary plaque progression remains unclear. Changes i...

Despite the link between positive coronary remodelling and acute ischaemic events, no data exist about the impact of arterial remodelling on subsequent progression of coronary atherosclerosis. The objective of this study was to examine whether extent and direction of arterial remodelling are predictors of progression of coronary atherosclerosis. De...

In patients with myocardial infarction, beta-adrenergic blockers reduce recurrent myocardial infarction and total mortality rates. However, whether a direct influence of beta-blockers on coronary atherosclerosis contributes to reduced recurrent myocardial infarction and total mortality rates is not known. To assess whether beta-blocker therapy is a...

The aim of this study was to evaluate the course of Thrombolysis in Myocardial Infarction (TIMI) frame count (TIMI FC) and myocardial perfusion grade (TIMI MPG) in heart transplant recipients and whether these parameters could predict mortality. Sixty-two heart transplant recipients were enrolled in this study. All patients had coronary angiography...

The purpose of this study was to determine the relationship between gender and the extent of coronary atherosclerosis assessed by intravascular ultrasound (IVUS) and its rate of progression in subjects treated with established medical therapies. It is uncertain whether the pathophysiology of coronary artery disease (CAD) differs between genders. A...

The relation between glomerular filtration rate (GFR) <60 ml/min/1.73 m(2) and the extent and progression of coronary atherosclerosis in 989 subjects with coronary artery disease was investigated. Despite being older, more likely to be women, and having a history of hypertension, diabetes, and bypass surgery, total atheroma volume and percent ather...

This study sought to determine the relationship between coronary calcification and plaque progression in response to established medical therapies. Coronary calcification correlates with the extent of atherosclerosis and predicts clinical outcome. Atheroma volume was determined in serial intravascular ultrasound pullbacks in matched arterial segmen...

Relative changes in lumen size during progression and regression of coronary atherosclerosis remain largely unknown. We assessed these changes using serial intravascular ultrasound (IVUS). From the baseline IVUS interrogations of the Reversal of Atherosclerosis with Aggressive Lipid Lowering (REVERSAL) trial, 210 focal coronary lesions with <50% an...

Arterial remodeling is a major determinant of the clinical manifestations of coronary artery disease. Assessment of arterial remodeling with intravascular ultrasound (IVUS) used to rely on comparing the external elastic membrane (EEM) areas of lesion and reference sites at a single time point (static assessment). Recently, performance of serial IVU...

The purpose of this study was to evaluate the effects of normal blood pressure (BP), pre-hypertension, and hypertension on progression of coronary atherosclerosis. The Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) classifies BP as normal, pre-hypertension, and h...

Inhibiting the enzyme acyl-CoA:cholesterol acyltransferase (ACAT) has beneficial effects on foam cell formation and therefore has the potential to favorably influence the progression of coronary atherosclerosis. The aim of this study is to determine whether ACAT inhibition, when added to usual medical care, reduces atheroma progression in subjects...

The background use of a number of established therapies presents a key challenge for the development of novel anti-atherosclerotic agents: how to predict potential efficacy before the completion of long-term trials with endpoints such as mortality. This challenge has stimulated the search to develop intermediate measures of efficacy. Recent advance...

Coronary plaque progression and instability are associated with expansive remodeling of the arterial wall. However, the remodeling response during plaque-stabilizing therapy and its relationship to markers of lipid metabolism and inflammation are incompletely understood. Serial intravascular ultrasound (IVUS) data from the Reversal of Atheroscleros...

The goal of this study was to determine the relationship between established cardiovascular risk factors and the extent of coronary atherosclerotic plaque. Few data exist correlating cardiovascular risk factors with volumetric measurements of coronary atheroma burden in patients with coronary artery disease. Clinical characteristics, quantitative c...

Prior intravascular ultrasound (IVUS) trials have demonstrated slowing or halting of atherosclerosis progression with statin therapy but have not shown convincing evidence of regression using percent atheroma volume (PAV), the most rigorous IVUS measure of disease progression and regression. To assess whether very intensive statin therapy could reg...

The enzyme acyl-coenzyme A:cholesterol acyltransferase (ACAT) esterifies cholesterol in a variety of tissues. In some animal models, ACAT inhibitors have antiatherosclerotic effects. We performed intravascular ultrasonography in 408 patients with angiographically documented coronary disease. All patients received usual care for secondary prevention...

The aim of this study was to determine the relationship between atheroma regression and arterial wall remodeling. Infusion of reconstituted high-density lipoprotein (rHDL) containing recombinant apolipoprotein A-I Milano (AIM) has been reported to promote rapid regression of coronary atherosclerosis. The current study analyzed intravascular ultraso...

Increasing interest has focused on possible viral triggers of cardiac allograft vasculopathy. Although much interest has centered on cytomegalovirus, it has recently been noted that donor hepatitis C seropositivity is associated with risk for accelerated vasculopathy. The current study hypothesized that hepatitis B (HBV) might be associated with ac...

The effect of moderate and intensive lipid lowering on plaque progression and arterial remodeling at coronary branch points was investigated. Intensive (+1 +/- 19.6%), but not moderate (+4.1 +/- 15.1%), lipid lowering prevented an increase in the percent [corrected] plaque area at the branch points. The 2 strategies were associated with increased a...

Hypertension is a potential risk factor for allograft coronary vasculopathy. We evaluated the efficacy of angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists, and their combined use, on the development of coronary vasculopathy in hypertensive heart transplant recipients. Eighty-two heart transplant recipients underwent serial int...

Objectives: The aim of this study was to determine whether angiographically silent early coronary intimal thickening could predict long-term morbidity and mortality. Background: Although intravascular ultrasound (IVUS) is widely used to detect early transplant coronary disease, its prognostic significance has not been well defined. Methods: Th...

Recent trials have demonstrated better outcomes with intensive than with moderate statin treatment. Intensive treatment produced greater reductions in both low-density lipoprotein (LDL) cholesterol and C-reactive protein (CRP), suggesting a relationship between these two biomarkers and disease progression. We performed intravascular ultrasonography...

Allograft vasculopathy is a major risk factor for mortality following cardiac transplantation. Several immune and nonimmune factors have been evaluated as risk factors for the development of coronary vasculopathy. We evaluated the influence of donor gender on the progression of coronary vasculopathy in heart transplant recipients. Eighty-nine heart...

We evaluated the impact of spontaneous intracranial bleeding (ICB) in the donor on transplant coronary vasculopathy using serial intravascular ultrasound examinations. Between January 1995 and December 2000, 72 recipients underwent cardiac transplantation from donors who had experienced spontaneous ICB (ICB group). Their findings using serial intra...

Despite improved treatment options, coronary artery disease remains the leading cause of death in men and women in industrialized societies. Reduction of atherosclerotic disease will require the development and evaluation of new classes of pharmacologic agents capable of modifying the development and progression of the atherosclerotic disease proce...

Previous studies of the association between acute cellular rejection and cardiac allograft vasculopathy (CAV) have yielded conflicting conclusions. We explored a possible association between acute cellular rejection and the extent of CAV, and we found a potential confounding variable that may obscure such an association. We investigated 140 patient...

Statin drugs reduce both atherogenic lipoproteins and cardiovascular morbidity and mortality. However, the optimal strategy and target level for lipid reduction remain uncertain. To compare the effect of regimens designed to produce intensive lipid lowering or moderate lipid lowering on coronary artery atheroma burden and progression. Double-blind,...

Donor cause of death has been suggested to have a significant impact on cardiac transplant morbidity and mortality. Our objective was to evaluate the impact of donor spontaneous intracranial bleeding on clinical outcome after heart transplantation. A group of 160 recipients underwent cardiac transplantation from donors with spontaneous intracranial...

Intravascular ultrasound studies describe ruptured coronary plaques at sites remote from the culprit lesion in patients with acute myocardial infarction (MI), suggesting multifocal plaque vulnerability. However, the role of intravascular ultrasound in the diagnosis of lesion vulnerability before rupture is unclear. We compared morphology and freque...

Although low levels of high-density lipoprotein cholesterol (HDL-C) increase risk for coronary disease, no data exist regarding potential benefits of administration of HDL-C or an HDL mimetic. ApoA-I Milano is a variant of apolipoprotein A-I identified in individuals in rural Italy who exhibit very low levels of HDL. Infusion of recombinant ApoA-I...

Early constriction of the external elastic membrane (EEM) area has been observed after cardiac transplantation. The aim of this study was to compare the late disease process of transplant vasculopathy between coronary segments with early constrictive and expansive remodeling. Serial intravascular ultrasound data obtained annually for 4 years after...

Atherosclerotic plaque burden is the major end point in ongoing progression trials. Intravascular ultrasound allows precise measurements of coronary artery dimensions. However, the variability of measurements among different catheter systems is incompletely characterized. Intravascular ultrasound imaging was performed in a cylindric phantom with 5...

Volumetric analysis of coronary arteries can be performed using intravascular ultrasound (IVUS) images selected at 1 mm intervals without ECG gating. However, there are few data regarding the influence of coronary pulsation on this volumetric analysis. We developed two models of consecutive area measurements consisting of duplicated area measuremen...

Using IVUS imaging we examined plaque distribution in the proximal left anterior descending artery in relation to the first septal perforator branch in patient with mild coronary artery disease. Atheroma burden was asymmetrically located on the site of the septal perforator branch and gradually tapered from proximal to distal.

Allograft coronary vasculopathy results from a complex interplay between immunologic and non-immunologic factors. We devised a computerized biopsy scoring method based on histopathology to predict the development of coronary vasculopathy. One hundred forty heart transplant recipients underwent serial intravascular ultrasound analysis at baseline (w...

We investigated the relation between the presence of matrix-metalloproteinases (MMPs) and direction of remodeling in the coronary lesions of 35 patients. Positive arterial remodeling describes a compensatory expansion of the external elastic membrane (EEM) area of atherosclerotic lesions. An association between positive remodeling and unstable clin...

We sought to assess the influence of peritransplant ischemia and fibrosis on the development of allograft vasculopathy, acute cellular rejection and long-term outcome. Allograft vasculopathy is a common long-term complication of cardiac transplantation. One of the potential risk factors is peritransplant allograft ischemia. One hundred forty heart...

Positive and negative remodeling can be observed at bifurcation lesions. Unstable presentation is associated with relative vessel expansion and stable angina with relative vessel shrinkage.

Coronary artery disease is the major cause of late cardiac allograft failure. However, few data exist regarding the natural history of changes in intimal and external elastic membrane (EEM) areas after heart transplantation. In 38 transplant recipients, serial intravascular ultrasound examinations were performed 3.7+/-2.2 weeks after transplantatio...

We sought to determine the role of conventional atherosclerosis risk factors in the development and progression of transplant coronary artery disease (CAD) using serial intravascular ultrasound imaging. Transplant artery disease is a combination of allograft vasculopathy and donor atherosclerosis. The clinical determinants for each of these disease...

During percutaneous coronary intervention of the left anterior descending coronary artery, a lumen narrowing was observed proximal to the stent just deployed. Intravascular ultrasound showed a hematoma localized outside the trilaminar wall structure in absence of a dissection flap or evidence of compression of the lumen. The luminal narrowing resol...

Intravascular ultrasound is a sensitive tool to study transplant vasculopathy. However, there is no consensus regarding the methodology for imaging protocol. The impact of single versus multiple epicardial vessel imaging in determining the prevalence of transplant vasculopathy has not been determined. This study examines the benefit of three-vessel...

The morphological characteristics of coronary plaques in patients with stable versus unstable coronary syndromes have been described in vivo with intravascular ultrasound, but the relationship between arterial remodeling and clinical presentation is not well known. We studied 85 patients with unstable and 46 patients with stable coronary syndromes...

Thrombolysis in Myocardial Infarction (TIMI) flow grading is limited by subjectivity and imprecision. The corrected TIMI frame count (cTFC) has been proposed to obviate these problems. We sought to validate the utility of the cTFC in predicting adverse clinical outcomes after reperfusion therapy. We used angiographic core laboratory data from the I...

Transplant coronary artery disease is a combination of atherosclerosis transmitted from the donor and new lesions of allograft vasculopathy. We sought to determine the morphological characteristics of allograft vasculopathy and differentiate it from donor-transmitted atherosclerosis with serial intravascular ultrasound. Intravascular ultrasound exa...

Background Platelet-mediated thrombosis has been implicated in the development of ischaemic complications of percutaneous coronary intervention. We investigated whether inhibition of the platelet glycoprotein IIb/IIIa integrin with eptifibatide (Integrilin) could prevent such complications. Methods We undertook a double-blind, placebo-controlled tr...

Animal experiments and epidemiological studies have suggested that coronary disease could be prevented, arrested, or even reversed by maintaining total serum cholesterol levels below 150 mg/dL (3.88 mmol/L). In 1985, we began to study how effective one physician could be in helping patients achieve this cholesterol level and what the associated eff...

A study was conducted to determine the ability of hamsters to eliminate in the urine, or store in the organs, large quantities of metal salts given over a period of several months. In addition, the effect of prior immunization on metal ion clearance was determined. The results indicated that nickel was rapidly eliminated in the urine and that the l...

A series of experiments was conducted to study in vitro and in vivo metal ion release and the urine excretion of metal ions. Metal salts were injected and urine analyzed. Anodic potentials were applied to stainless steel and cobalt-chromium-molybdenum (CCM) specimens to cause an acceleration of corrosion rates. Corrosion experiments were done in sa...

The injection of a single bolus of the gas phase of cigarette smoke into the airway of an isolated, perfused and ventilated, canine lung preparation resulted in a sevenfold increase in lung cyclic GMP content by 2 s after exposure. Recovery of control levels occurred by 2 min after injection. Repeated smoke exposures of the same lung resulted in si...

Rat small intestinal brush border membranes are purified from brush borders by homogenization in relatively high concentrations of thiocyanate salts (0.56 M LiSCN, 0.41 M NaSCN, or 0.52 M KSCN), removal of this salt, and differential centrifugation to separate cytoskeletal material from membranes. The marker enzyme, sucrase, is enriched 98-fold in...