不安定狭心症の臨床像の検討

Clinical characteristics of unstable angina in 162 consecutive cases

　急性心筋梗塞症例の47〜65％には新しい心症状もしくは増悪する心症状といった前兆があるといわれている^1,2）。かかる梗塞前狭心症（不安定狭心症）に対し，薬物療法以外にバイパス手術の有用性の検討がなされてきた3）。最近では大動脈バルーンパンピング（IABP）^4）や冠動脈形成術（PTCA）^5）といった新しい治療法が導入され，効果をあげつつある。我々は，過法3年間に当施設に入院した不安定狭心症症例を検討し，従来の報告をふまえて臨床的な考察を加えた。

We surveyed the clinical characteristics, treatment,and prognosis of 162 patients with unstable angina, who were admitted to our center between 1985 and 1987. There were 112 males and 50 females, with a mean age of 65 years. The clinical characteristics according to the American Heart Association classi-fication were new angina of effort in 21%, changing pattern in 61%, and new angina at rest in 18% of the patients.

ECG recordings during attacks of angina were ob-tained in 70%, and ST elevation was detected in 11%, ST depression in 54%, and T wave abnormality in 5%.

Coronary arteriography performed in 42% of the patients revealed single vessel lesion in 21%, two vessel lesion in 10%, three vessel lesion in 5%, and left main trunk lesion in 3% of the patients.

Seventy-seven percent of the patients were control-led by medical therapy, including nitrates, calcium antagonists, and, in some cases, beta blockades. Three percent of the patients were controlled with intra aortic balloon pumping in addition to medical ther-apy.

Coronary artery bypass graft surgery (CABG) was performed in 6% of the patients. Since 1987, percuta-neous transluminal angioplasty (PTCA) was introduced in our center and PTCA was performed in 9 patients (6%). Restenosis of the dilated portions of the coro-nary artery was observed and PTCA was again performed in 2 of 9 patients (22%). All patients who received CABG or PTCA survived and have been free from angina or myocardial infarction.

Non-fatal myocardial infarction occured in 10 cases (5.6%) and fatal infarction occured in one patient (0.6%).