Background : Left main tract disease (LMTD) has been found to be the most important single lesion for the assessment of prognosis in coronary arteries disease and accompanies grave clinical outcome. This survey was designed to determine the difference between ischemic risk factors and LMTD.

Materials and Method : In a case-control study we reviewed the data of 7857 patients who had undergone coronary angiography in Tehran Heart Center, during 2003 and 2004. Based on angiography findings, the patients were categorized into 3 groups: normal coronary vessels (control group: 1316), coronary artery disease (CAD: 6221), and LMCA≥50% stenosis (LMTD: 320). Multivariate analysis was performed by logistic regression.

Results: The mean age of patients was 57.56±10.22 years. LMTD was seen in 4.1% of cases. The frequency of well-known cardiovascular risk factors as well as opium addiction was significantly more in the patients with CAD than in the control group. Comparison of the CAD patients with and without LMTD showed that the patients with LMTD were older, with higher male predominance and hyperlipidemia history.