Hirokuni Etsuda

Angioscopy in variant angina : coronary artery spasm and intimal injury

Studies in pigs and dogs show that intimal injury is related to coronary artery spasm; it is not known whether intimal injury is related to coronary artery spasm in human beings. We examined intima at the site of coronary artery spasm by percutaneous transluminal coronary angioscopy in 10 of 13 consecutive patients with variant angina. Coronary artery spasms occurred spontaneously or were induced by intracoronary acetylcholine (10-100 micrograms). Angioscopy showed intimal injuries (haemorrhage, flap, thrombus, or ulcer) in 4 of the 10. We suggest that intimal injury is related to coronary artery spasm in human beings.

Effect of Chronic Oral Supplementation with Vitamins on the Endothelial Function in Chronic Smokers

Cigarette smoking has been associated with endothelial dysfunction including impaired endothelium-dependent flow-mediated dilation (FMD). In cigarette smokers, increased oxygen-derived free radicals have been suspected of being one of the major causes of endothelial dysfunction, owing possibly to the inactivation of nitric oxide by free radicals. Vitamins C and E are widely used antioxidant vitamins, which have also been reported to effectively improve the endothelial function in several conditions. To test the effect of moderate-term oral antioxidant vitamin supplementation on the endothelial function in smokers, the authors evaluated the combined effect of vitamins C and E, administered in normal dosages, on FMD in young male smokers. A prospective interventional study was performed. In 15 healthy male subjects (mean age, 24.4 ±2.5 years old). They studied FMD in the brachial artery by using high-resolution ultrasound. The vascular effects of moderate-term oral supplementation with vitamin C (1.0 g/day) and vitamin E (500 mg/day) were determined during reactive hyperemia, which causes endothelium-dependent FMD. They performed a vascular function study 3 times including before vitamin supplement, after 25 days of vitamin supplement, and 4 weeks after the cessation of the vitamin supplement. The flow-mediated dilator response measurements were repeated twice a day before vitamin supplements, and the repeatability obtained from these measurements was found acceptable (variability of FMD <2%). The oral antioxidant vitamin supplement significantly restored FMD (3.8 ±2.2% vs 5.9 ±2.5%; p<0.05), however, this effect disappeared 4 weeks after the vitamin supplementations ended. The combined usual dosage of vitamins C and E supplements was found to improve the endothelial function in chronic smokers.

Plasma fibrinogen level is related to intimal pathology in coronary spastic angina

Fibrinogen promotes atherosclerosis and thrombosis. To evaluate the possibility that plasma fibrinogen levels represent a marker of atherosclerosis or are a predictor of cardiac events in coronary spastic angina, we studied the relation between plasma fibrinogen values and coronary angioscopic findings. We measured plasma fibrinogen in 20 patients with coronary spastic angina, 19 patients with chronic stable angina and 22 control subjects. Percutaneous angioscopic examination was performed in the patients with coronary spastic angina at the site of vasospasm induced by acetylcholine and in those with chronic stable angina at the site of organic coronary stenosis. Fibrinogen levels were significantly higher in those with coronary spastic angina (308.4±83.0 mg/dl) and chronic stable angina (289.4±69.3 mg/dl) than in the controls (239.5±49.9 mg/dl) (p<0.01, coronary spastic angina vs control;p<0.05 chronic stable angina vs control). Angioscopy showed intimal injuries (hemorrhage, flap, thrombus and/or ulcer) in 9 of the 20 (45%) coronary spastic angina patients, and flap or ulcer in 2 of the 19 (11%) chronic stable angina patients. Hemorrhage and/or thrombus were shown in 6 of the 20 coronary spastic angina patients. In the coronary spastic angina group fibrinogen levels were significantly higher (p<0.05) in those with than without hemorrhage and/or thrombus (365.3±97.4 mg/dl vs. 238.9±65.4 mg/dl). These results suggest that elevated fibrinogen levels in patients with coronary spastic angina are associated with atherosclerosis and thrombus formation.