Computerized tabulation of cine coronary angiograms. Its implication for results of randomized trials

[Physiologic evaluation of coronary circulation. Role of invasive and non invasive techniques]

For many years, the evaluation of the extent and severity of coronary artery disease has been mainly anatomical, carried out by coronary angiography. However, this technique has methodological limitations and interobserver variability is considerable. Quantification of coronary reserve with pressure guidewires and intracoronary Doppler now provides more precise physiologic evaluation of coronary circulation. Myocardial perfusion single proton emission computed tomography and echocardiography, combined with stress and/or pharmacological challenge testing, though they are only semiquantitative techniques, also offer appropriate complements to coronary angiography in the functional evaluation of coronary patients. The aim of this paper is to discuss the clinical value of these techniques.

Quantitative angiographic follow-up studies on the development of coronary artery disease: which coronary segments should be analyzed? Experience from INTACT

Angiographic follow-up studies on the evolution of coronary artery disease are of increasing relevance. It has still to be evaluated which coronary segments are predominantly involved in the process of atherosclerosis and, thus, should be preferably included in the analysis. Therefore, the correlation of progression and regression of coronary disease with the diameter and location (proximal, mid or distal) of coronary segments was investigated from the data of the INTACT-study, in which 25 different coronary segments were defined including anatomic variants of rather distal segments. In 348 patients with coronary artery disease, standardized coronary angiograms were repeated within 3 years and were quantitatively analyzed (CAAS). In 1063 coronary stenoses (% diameter stenosis > 20%) compared from both angiograms, progression and regression were not influenced by diameter nor location of arterial segments. In the follow-up angiograms, the number of new lesions (stenoses and occlusions) per coronary segment differed with regard to segment diameter (> 3 mm: 64/1125 (6%); 2-3 mm: 139/1967 (7%); < 2 mm: 44/1756 (2%); p < 0.001) and location of segments (proximal: 86/1285 (7%); mid: 84/1193 (7%); distal: 77/2370 (3%); p < 0.001). Out of 77 distal new lesions, only 25 (32%) were found in segments < 2 mm in diameter. Since the absolute number of new lesions was high in distal coronary segments, but low in segments with diameters < 2 mm, angiographic follow-up studies should analyze coronary segments at any location, but may neglect segments with diameters smaller than 2 mm.

Segmental analysis of coronary arterial stenoses in patients presenting with angina or first myocardial infarction

The segmental distribution of stenoses within the coronary arteries was analysed in a population of 258 patients with a first myocardial infarction undergoing coronary angiography to evaluate the effect of thrombolytic therapy, and in a population of 466 patients undergoing elective coronary angiography for stable angina. Mean ages were 53.7 and 56.7 years respectively (P = NS). As judged angiographically, coronary arterial disease was more extensive in the group suffering angina, with a greater proportion of patients with two- or three-vessel disease (odds ratio 2.56, 95% confidence interval 1.87 to 3.52) and more patients having stenoses in two or more coronary arterial segments (odds ratio 1.52, 95% confidence interval 1.12 to 2.08). For each coronary vessel, the probability of finding a stenosis greater than 50% in an individual segment was greater in the group presenting with angina. There was a relative deficiency of stenoses within the main stem of the left coronary artery or its proximal left anterior descending branch among the patients suffering myocardial infarction. Within those having angina, subgroups were identified with "isolated" and "diffuse" coronary arterial disease: the latter patients tended to have a lower concentration of total cholesterol in the serum, but an increased prevalence of diabetes mellitus. Patients presenting clinically with a first myocardial infarction, and patients with severe angina, constitute distinct populations selected by different mechanisms from the overall pool of patients with atheromatous coronary arterial disease.