Takayuki Miyake

Relation Between Plasma Fibrinogen Level and Coronary Plaque Morphology in Patients With Stable Angina Pectoris

I vivo studies have demonstrated yellow plaque, as seen on angioscopy, to be common in the culprit lesions of acute coronary syndromes,1 and this plaque also has a predictive value for cardiac events in patients with stable angina pectoris.2 This suggests that yellow plaque is vulnerable and prone to rupture. Plaque rupture may be enhanced by the inflammatory process,3 which is considered to be involved in atherosclerotic vascular disease.4 The extent of coronary atherosclerosis proved by coronary angiography has been reported to be associated with plasma fibrinogen,5 which is an acute-phase protein, and its level changes during the inflammatory process. However, the relation between the intracoronary plaque morphology and plasma fibrinogen is less clear. We therefore examined this relation in patients with stable angina pectoris using percutaneous transluminal coronary angioscopy. • • • Eighty-three patients (71 men and 12 women; average age 57 6 7 years) with stable angina pectoris who had 1-vessel disease served as subjects in this study. They were selected from a pool of 186 consecutive patients with stable angina pectoris who underwent coronary angioscopy between May 1990 and October 1997 at our hospital. Of the 103 patients not included, 38 patients with prior myocardial infarction (onset of myocardial infarction ,3 months) were excluded because the inflammatory process of infarcted myocardium might have influenced the plasma fibrinogen level a few months after myocardial infarction. Twenty-five patients who underwent coronary angioplasty within 6 months were also excluded because recent angioplasty procedures could have influenced the color of the plaque. Twenty-one patients with multivessel disease were excluded because the intracoronary plaque characteristics of the other lesions, which were not observed by angioscopy, might have influenced the plasma fibrinogen. Thirteen patients were excluded because of an incomplete coaxial angioscopic view for color assessment, and 6 patients were excluded owing to disagreements regarding the classification of the lesion among at least 2 observers.

Parametric study for laser hot balloon angioplasty to suppress chronic restenosis: animal experiment

To suppress restenosis after the percutaneous transluminal coronary angioplasty (PTCA), we experimentally investigated the optimum parameter setting on the combination of the balloon temperature and heating duration of our laser hot balloon catheter in rabbit model. The rabbit femoral arteries were treated by our laser hot balloon of 2.5 mm in diameter with various balloon temperatures and durations at the range from 60 to 90 deg., and from 15 to 30 seconds, respectively. The histological examination showed that high temperature (greater than 70 deg.) was necessary to suppress hyperplasia of the vessel in chronic phase. The angiography of pre- and post-treatment and of 2 months after the treatment showed that high temperature with short heating duration (15-30 s) was the best setting for chronic patency of the treated vessels. The laser hot balloon angioplasty with the above mentioned parameter setting might realize significant improvement on chronic patency after PTCA.

Significant usefulness of heart rate variabilities by ambulatory electrocardiographic monitoring in diabetes mellitus, congestive heart failure and ischemic heart disease

ホルター心電図より求めた心拍数変動の指標のうちSD, LF, HFを用いて糖尿病, うつ血性心不全, 虚血性心疾患の3群の重症度について検討した.その結果, 糖尿病群で自律神経障害を有している群のSD, LF, HFともに, 有していない症例に比べて有意に低値であった.うっ血性心不全群ではNYHA4群のLF, HFともにNYHA2群に比べて低値であった.また死亡群のSDは生存群に比べて有意に低値であり, 治療により非代償期から代償期になるに従いSDは上昇した.虚血性心疾患群では死亡群のSDは生存群に比べて低値で, 生存群でも多枝障害で左室機能の低下群 (EF<50%) のLF, HFともに低値であったが有意差はなかった.SD<20ms, SD<30msの信頼度はsensitivity, specificityは30から100%であった.なお健常者3名の高圧環境 (41気圧) 4日目ではLF, HFともに心拍数に比べて著明に変動した.以上よりSD, LF, HFとも各種病態の異常を反映しており, 予後を判定する際有用であるが, 必ずしも自律神経の異常のみでは説明できない可能性がある.