Arteriographic assessment of coronary atherosclerosis. Review of current methods, their limitations, and clinical applications.

Abstract

Coronary arteriography is presently the definitive procedure for characterizing the location and severity of coronary atherosclerosis; and despite certain reported limitations, we believe that the properly performed coronary arteriogram provides a true picture of the arterial lumen in life. Yet this widely-used clinical tool is currently limited by imprecise and, to a certain extent, inappropriate subjective methods of interpretation. More objective methods for analysis of the arteriographic information content have been described. These include caliper- and vernier- based systems for measuring relative arterial narrowing, computer-assisted methods for making accurate measurements of absolute stenosis dimensions, and photodensitometric methods for extracting three-dimensional information from a planar image of the stenosis. The availability of these objective techniques has resulted in a considerable increase in our understanding of pathogenic mechanisms in coronary disease. Advances include an expanded understanding of the mechanisms of action of nitroglycerin and verapamil and of the coronary artery constriction induced by drugs of isometric stress. Stenosis measurements have served as the basis for evaluation of certain noninvasive techniques used to detect coronary disease. An analytical approach has been developed to characterize the progression (and regression) of coronary disease from serial arteriograms. We believe clinical investigations based on these techniques hold considerable promise for further advances in the understanding of human coronary pathophysiology.

Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy.

“…14 23 From these data, obtained in a clinical setting, a curvilinear relationship was found between the pressure drop across the stenosis and the minimal obstruction area as well as the percent cross-sectional area reduction. Both relationships are similar to those calculated on theoretical grounds by Brown et al 34 as well as to those experimentally derived from isolated human arteries35 or in canine experiments.3 Such a curvilinear relationship is expected from the general equation of fluid dynamics showing that a pressure drop across a stenosis is influenced mainly by viscous losses in the stenotic segment and separation losses at the exit of the stenosis. For a given level of flow, the single most important determinant of stenosis resistance is its minimal cross-sectional area, which appears as a second-order term in both viscous and separation loss equations.…”

George Lyman Duff Memorial Lecture. Arterial imaging and atherosclerosis reversal.

“…Angiograms were separated in time by an average of 2.5 years and analyzed by a computer-assisted method. 25 In the control group, 46% of subjects had lesion progression in at least one of nine proximal coronary segments. Progression was less frequent in subjects treated with colestipol-lovastatin (21%) and colestipolniacin (25%).…”

“…First, when multiple coronary lesions are present, the extent of concurrent myocardial damage influences symptoms and risk. 24 Second, equations predicting blood flow from lesion measurements in an unbranched vessel 25 oversimplify real coronary blood flow, which pulsates through highly branched vessels. 26 Last, certain plaques are likely sites for the local catastrophe of plaque fissuring with hematoma or thrombosis causing a rapid increase in size.…”

“…The control group comprised those treated with diet alone and those with diet plus colestipol. After 2 years of treatment, angiograms were evaluated with per-subject averages in percent area stenosis determined by the computerassisted method of Brown et al 25 Mean change in percent area stenosis among control subjects was +0.80, indicating progression, whereas mean change for the treatment group was -1.53, indicating regression (P=.O39). When analyzed separately, lesion change among women was significant (P=.O5), whereas for men it was not (P=.42).…”

Relation of extent of extracranial carotid artery atherosclerosis as measured by B-mode ultrasound to the extent of coronary atherosclerosis.

“…Patients with nonobstructive CAD (percent stenosis less than 50%) were excluded from analysis because Fried and Pearson 19 have shown that such patients in fact have extensive disease and are difficult to categorize. In addition, Brown et al 20 have shown that assessment of coronary stenosis of 30-50% is highly variable and poorly reproducible among observers. Patients were considered to have normal coronary anatomy if no evidence of luminal irregularities was noted by the angiographer.…”