Analysis of Risk Factors in Coronary Artery Bypass Surgery

Jung, Tae Eun; Han, Sung Sae

Abstract

BACKGROUND: Coronary artery bypass surgery is an important treatment for ischemic heart disease. Recently operative mortality and morbidity has decreased, however further improvement is necessary. MATERIALS AND METHODS: This study was designed to evaluate the risk of operative mortality and morbidity by retrospective method. From 1992 to 1997, eighty six patients underwent coronary artery bypass surgery. There were 61 males and 25 females aged 36~74 years (mean, 58.6). Fourteen patients (16%) had previous PTCA or stent insertion, 41 patients (48%) had unstable angina, and 45 patients (52%) had three vessel disease. Patients with low LV ejection fraction (<35%) were 7 cases and urgent or emergent operation were 10 cases. There were 6 cases of combined surgery which were mitral valve replacement (2 cases), aortic valve replacement (2 cases), ASD repair (1 case), and VSD repair (1 case). Average number of distal anastomosis was 3.5 per patient and average aortic cross clamp time was 115+/-38.3min. Preoperative risk factors were defined as follows: female, old age (>70 years), low body surface area (<1.5M2), PTCA or stent insertion history, hypercholesterolemia, smoking, hypertension, DM, COPD, urgent or emergent operation, left main disease, low LV ejection fraction (<35%), and combined surgery. RESULTS: Operative mortality was 7cases (8%). As a postoperative morbidity, perioperative myocardial infarction was 6 cases, cerebrovascular accident 6 cases, reoperation for bleeding 5 cases, acute renal failure 4 cases, gastrointestinal complication 3 cases, and mediastinitis 3 cases. In the evaluation of operative risk factors, low body surface area, DM and low LV ejection fraction were found to be predictive risk factors of postoperative morbidity (p<0.05), and low ejection fraction was especially a risk factor of hospital mortality (p<0.05).
CONCLUSIONS
In this study, low body surface area, DM and low LV ejection fraction were risk factors of postoperative morbidity and low ejection fraction was a risk factor of hospital mortality.