Abstract
Background: Isolated ostial stenosis (IOS) of the left coronary artery is a rare disease of unknown etiology, and the long-term prognosis and angiographic characteristics of affected patients have not been fully studied. Methods and Results: The present study investigated 57 patients with stenosis of the left main trunk (LMT) who underwent coronary artery bypass grafting (CABG). They were categorized into 3 groups, based on the angiographic findings: Group I comprised 9 patients with IOS; Group II comprised 12 patients with left coronary ostial stenosis in the presence of distal vessel obstructions; Group III comprised 36 patients with stenosis of LMT excluding ostial stenosis and associated with distal vessel obstruction. The patients underwent serial angiography at 1, 5, and 10 years after CABG. Middle aged women with fewer coronary risk factors were more common in Group I compared with Groups II and III (P<0.01). The patency rate of the internal thoracic artery grafts was significantly higher in Groups II and III than in Group I (P<0.05). In Group I, the percentage stenosis of LMT lesions decreased significantly (P<0.05), but there was no difference in the other groups. Conclusions: IOS had clinical characteristics and time course distinct from those of atherosclerotic LMT disease. (Circ J 2009; 73: 1271-1277)
