Early Result of Surgical Revascularization for Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: There are relatively few studies that have evaluated the optimal timing, risk of mortality, and outcome for patients with coronary artery bypass graft surgery (CABG) performed in the setting of acute myocardial infarction (AMI). MATERIALS AND METHODS: We reviewed our 18 patients who underwent CABG within 14 days after AMI, between June 1994 and June 1997. Thirteen of the patients were male and 5 were female. Their ages ranged from 41 to 77 years (mean age, 60.6+/-10.4 years), and the amount of time betweenAMIandCABGrangedfrom4hoursto14days (meantime,7.0+/-4.7days).Therewere11 anteroseptal infarctions and 7 inferior wall infarctions. Eleven patients had transmural infarctions and 7 had subendocardial infarctions. Indications of operations were postinfarction angina, cardiogenic shock and intractable ventricular arrhythmia. Six patients required preoperative intra-aortic balloon pump (IABP) support, and 3 additional patients required IABP to be separated from cardiopulmonary bypass. An average of 3.4+/-0.5 vessels per patient were bypassed. RESULTS: The early mortality rate for these 18 patients was 5.6% and late mortality rate was 5.9%, and 2-year actuarial survival rates were 89.5%. Univariate analysis of mortality showed that an ejection fraction less than 30% was associated with risk factor (p value=0.016 ). Age, sex, time to CABG, emergency operations, locations of infarctions were not significant. CONCLUSION: Although our studies have weak points in that there was only a small number of patients and the lack of long-term results, we could conclude that early myocardial revascularization is relatively safe after AMI for those individuals with an ejection fraction greater than 30%.

Clinical, Angiographic Characteristics and Long-Term Follow-up in Patients with Variant Angina

BACKGROUND: Several Studies from western institutes were done on the clinical characteristics and long-term prognosis of patients with variant angina. In these reports, 61-92% of patients had significant coronary artery disease, and survival without myocardial infarction at 1 year was approximately 70-83%. These results differ from our clinical experiences with Korean patients with variant angina;however, no detailed study has been reported in Korea. The purpose of this study was to describe the clinical characteristics and long-term follow-up data of our Korean patients with variant angina. METHODS: Two hundred four consecutive patients with variant angina(M/F;166/38, mean age 53+/-10 year) were included. The diagnosis of variant angina was made by spontaneous spasm in 53, positive intravenous ergonovine(iv Erg) provocation in 52, intracoronary acetylcholine(ic Ach) provocation in 55, simultaneous iv Erg and ic Ach provocation in 48 and bedside intravenous ergonovine with 2-dimensional echocardiography in 33. The clinical and angiographic characteristics were examined in 204 patients and mean 1.5 year(6 month to 3.5 year) follow-up could be done in 165 for the evaluation of long-trem prognosis. RESULTS: The Korean patients with variant angina were characterized by relatively low prevalences of significant coronary stenosis(25%), myocardial infarction and rate of cardiac death. Futhermore, survival and survival without myocardial infarction for the entire group were significantly better in our observation(1 year survival without myocardial infarction, 98%) than in other studies. During the follow-up period, 4(2%) out of 165 patients died, 1 developed myocarddial infarction and ventricular fibrillation occurred in 2. Three of 4 death caused by stopping medication abruptly. Thirteen patients were angina free after discontinued medications during the follow-up. CONCLUSION: The overall prognosis of variant angina may be better in Korean patients. We believe that less severe coronary atherosclerotic disease and a high rate of treatment with calcium blockers may have contributed to the lower rate of cardiac death and myocardial infarction on our patients compared with those in previous studies.

Acetylcholine Response of Infarct-Related Coronary Arteries with and without Stenotic Lesions

BACKGROUND: A small percentage of patients presenting with acute myocardial infarction are found to have angiographically normal or near normal coronary arteries. Thrombus, coronary spasm or coronary embolism have been thought to cause myocardial infarction in these circumstances. Acetylcholine(Ach) may dilate coronary arteries indirectly by releasing EDRF(endothelium derived relaxing factor), but constrict arterial smooth muscle when endothelium is dysfunctional or denuded. In this study, we observed Ach responses of infarct related arteries with and without stenotic leisions to clarify the possible etiologic role of vasospasm in ischemic heart disease. METHODS: Seven to ten days after acute myocardial infarction. Ach(100ug for left and 50ug for right )responses of infarct-related coronary was studied in 16 patients with angiographically normal coronary arteries(Group 1) and 15 patients with significant stenotic lesions(Group 2). Ach responses was also studied in 27 noninfarct related arteries(NIRA) of group 1 and 29 NIRAs of group2. The positive response was defined as total or subtotal occlusion after Ach injection. In 6 patients of group 1 with Ach(+), intravenous ergonovine(Erg) test was also performed after completion of Ach test. RESULTS: 1) Ach(+) responses of IRAs with or without significant coronary artery disease was more frequent(70%) than that of NIRAs(14%). 2) Ach(+) response of IRAs with angiographically normal coronary artery (87.5%) was more common than that with significant fixed disease(45.4%). 3) ACh and ergonovine induced vasospasm at the same site in 4 of group 1. CONCLUSIONS: In the majority of patients with normal coronary artery and acute myocardial infarction(AMI), Ach induced vasospasm in the IRAs. Ach(+) response occured more frequently in normal coronary arteries. These findings suggest that coronary vasospasm might etiologic role for AMI. especially in thoses patients with normal coronary artery. However our investigation failed clarify whether the those responses of IRAs to Ach was a cause or a result of myocardial infarction due to the post-ischemic injured endothelium. Ach and Erg induced vasospasm at the same site in 4 of group 1 which suggests that local hyperreactivity might be related to coronary spasm.