ackground : Unstable angina progresses to acute myocardial infarction or sudden death.
Pathophysiologic mechanism of unstable angina is still to be defined. Comparative study of
coronary angiographic morphologies and clinical features may be a help to look into the
pathogenesis of the unstable angina.
Methods : The eighty one patients with unstable angina were examined angiographically,
Of the 81, 11 had no significant stenotic lesions and 9 had compeltely occluded lesions. The
remaining 61 patients diagnosed as unstable angina (20 severe recent angina or accelerating
angina: class Ⅰ, 18 subacute resting angina: classⅡ, 23 acute resting angina: class Ⅲ,
according to the classification of Braunwald) were subjected to the analysis of coronary
angiographic motphology in the study. All the patients were treated with intravenous if not
contraindicated at admission. The coronary angiography was performed after symptoms had
been stabilized in almost all patients average 4.2 days after admision. The culprit lesion
morphology of each patient was subjected to analysis.
Result :
1) Male to female ratio was 1.9 to 1. The most prevalent age was of fifties and 47
patients (77%) of 61 were older than 50 years. The age of the patients was 56.5±9.8 years in
class Ⅰ, 54.7±8.6 in class Ⅱ, 56.2±9.1 in class Ⅲ. There was no age difference among
three classes.
2) The most commonly associated risk factors were smoking (42.6%), hypertension
(26.2%), hypercholesterolemia more than 220 mg/dl (21.3%) of total cholesterol and diabetes
mellitus (16.4%).
3) Thirty one cases (50.8%) of 61 had single vessel disease, 26 had multivessel disease
and 4 had left main disease. Except the fact that the 4 cases of left main disease were all
belonging to class Ⅲ, there was no difference of the number in diseased vessels among the
classes.
4) The mean diameter stenosis of class Ⅰwas 67.9±9.2%, classⅡ 70.3±6.9% and class Ⅲ
70.6±9.6%. There was no significant difference in the degree of obstruction among three
classes.
5) The site of culprit lesions were mostly the proximal or middle portions of the coronary
arterial trees. Thirty two in left anterior descending, 14 in left circumflex 11 in right
coronary. There was no significant difference in the site of culprit lesion among three classes.
6) Complex lesion defined as type Ⅱ eccentric senosis or multiple irregular lesion by
Ambrose classification was observed in 3 cases (15.0%) of class Ⅰ, 8 (44.5%) of class Ⅱ and
15 (65.2%) of class Ⅲ.
Conclusion : The complex lesions, lesions of narrowed base with overhanging edges or the
lesions with multiple irregularities on the narrowed lesion walls, were prevalent in rest angina
and more frequent in acute rest angina. It suggested that the patients with rest angina and
the more likely with acute rest angina are apt to have plaque ulcerations or thrombosis.
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