Intravascular ultrasound assessment of lumen size and wall morphology in normal subjects and patients with coronary artery disease.

SummaryCAD remains a major global cause of morbidity and mortality. Comprehensive drug development programs of novel pharmacological treatment strategies frequently utilize traditional mortality/morbidity endpoints studies and additional surrogate endpoints trials. This parallel approach allows an assessment of efficacy several years in advance of the availability of data from clinical endpoint trials. Several atherosclerosis imaging markers have been introduced into these drug-development strategies, including angiography, carotid ultrasound, IVUS, MRI, and CT. This review will discuss the current status of atherosclerosis imaging as an endpoint in progression/regression trials, with an emphasis on evidence-based data. In addition to a discussion of the results of individual imaging modalities, the emerging data comparing different modalities and approaches are presented.

Section: Plaque Composition With Ivusmentioning

confidence: 99%

Métodos por imagem da aterosclerose em estudos de progressão/regressão: marcador substituto ou janela direta para o processo patológico da aterosclerose?

Schoenhagen¹,

Tuzcu²

2008

“…It has already been demonstrated by intravascular ultrasound and also by pressure measurements, that the presence of a focal stenosis is almost always associated with diffuse atherosclerosis of coronary vasculature [3][4][5][6] . Even after successful stenting of a focal stenosis, a residual gradient may remain with an abnormal FFR if pressure is measured in the distal part of the artery.…”

Section: Discussionmentioning

confidence: 95%

“…Pathological and intravascular ultrasound studies have shown that when a stenosis is visible at angiography, the remainder of the coronary tree is often diffusely involved by atherosclerosis, although this may not be identified by coronary angiography [2][3][4][5] .…”

Section: It Is Well Known That Coronary Atherosclerosis Is Often a DImentioning

confidence: 99%

Doença aterosclerótica difusa desmascarada pela avaliação fisiológica invasiva da circulação coronária

Sant’Anna¹,

Silva²,

Batista³

et al. 2005

It is well known that coronary atherosclerosis is often a diffuseCoronary circulation is generally considered a two compartment model, which consists of epicardial vessels, also referred as "conductance vessels" and microcirculation, arteries <400 mm or "resistive vessels" 1 . When there is no stenosis, myocardial flow is primarily controlled by resistive vessels.Pathological and intravascular ultrasound studies have shown that when a stenosis is visible at angiography, the remainder of the coronary tree is often diffusely involved by atherosclerosis, although this may not be identified by coronary angiography 2-5 .De Bruyne et al. showed that diffusely atherosclerotic epicardial coronary arteries in contrast to truly normal coronary arteries often cause a continuous pressure decline along their length, reduce fractional flow reserve, contribute to myocardial ischemia and abnormal perfusion during exercise and pharmacological vasodilatation, and are identifiable by intracoronary pressure measurements 6 .Fractional flow reserve (FFR) is defined as the ratio of maximal hyperemic blood flow in the presence of a stenosis divided by normal hyperemic blood flow without stenosis and is calculated as the ratio of distal coronary pressure (Pd) divided by aortic pressure (Pa) at maximum hyperemia (FFR=Pd/Pa) 7 . The larger the resistance to blood flow, the larger the decline in pressure and, thus, the smaller FFR. Therefore, FFR is an index of resistance to flow along the epicardial vessel and is not affected by changes in blood pressure, heart rate and other pathologic conditions. Even if microcirculatory disease is present, FFR still gives the (abnormal) resistance to flow along the epicardial artery, given that state of microcirculatory disease. FFR and its properties have been well validated over recent years [8][9][10] . Importantly, FFR below 0.75-0.80 discriminate lesions which are associated with inducible ischemia with a diagnostic accuracy of almost 100% 9,10 .The present report describes a patient with stable angina who had a severe stenosis in the left anterior descending (LAD) coronary artery. Measured FFR was 0.37 and thus indicative of important ischemia. A major, focal gradient was present across the stenosis itself. After treating this lesion by stent implantation, FFR improved significantly but still remained inside the area for inducible ischemia. However, coronary pressure tracings obtained by the pullback curve under maximal hyperemia showed no gradient across the stent individually deployed well, but a continuous increase from distal to proximal LAD typical of diffuse atherosclerotic disease. This report might demonstrate how FFR can unmask diffuse atherosclerotic disease after treatment of a focal lesion. Case ReportA 58-year-old male, suffering from AMI 3 months earlier, presented at outpatient clinic with typical recurrent chest pain at moderate exercise. Known risk factors were hypercholesterolemia and arterial hypertension. Physical examination was normal. Resting ECG showed Q-waves with absent ...

“…1). Em 30 a 50% dos casos em que as artérias coronarianas são normais, a camada íntima é fina e reflete pouco ultra-som, portanto não pode ser visualizada como uma camada separada 7 . A túnica média tem pouco conteúdo de colágeno e é constituída, basicamente, por tecido muscular, sendo tipicamente ecoluscente ao ultrasom.…”

Section: -Interpretação Do Ultra-som Intracoronarianounclassified

Diretriz de indicações do ultra-som intracoronariano na prática clínica

Costantine¹,

Mattos²,

Caixeta³

et al. 2003