Left coronary ostial stenosis: comparison with left main coronary artery stenosis.

We compared 147 consecutive patients who had left coronary ostial stenosis with 254 consecutive patients who had left main coronary artery stenosis treated with coronary artery bypass grafting. Mean age for the left main group was 61.6 years versus 59.7 years for the left ostial group (p = not significant [NS]). In the left ostial group, 43.5% were female and in the left main group, 12% (p less than 0.005). Prior myocardial infarction had occurred in 53% of patients with left main stenosis and 36% of patients with left ostial stenosis (p less than 0.005). There were 2.45 +/- 1.00 diseased vessels in the left main group and 1.96 +/- 1.09 in the left ostial group (p less than 0.0005). Seven (3%) of the patients with left main stenosis had no associated coronary disease (greater than 50%) versus 24 (16%) of the left ostial group (p less than 0.005). The degree of left main stenosis was 90% or more in 28.3% of patients versus 42.8% with equivalent ostial narrowing (p less than 0.01). Left ventricular function was better in the left ostial group than in the left main group (1.61 +/- 0.93 versus 2.02 +/- 1.11, respectively; p less than 0.0005). One-month mortality was 10 patients (3.9%) in the left main group and 8 (5.4%) in the left ostial group (p = NS). Perioperative infarction occurred in 8.6% of patients with left main stenosis and 4.7% of patients with left ostial stenosis (p = NS). Mean follow-up was 6.1 years for the left main group and 5.4 years for the left ostial group.(ABSTRACT TRUNCATED AT 250 WORDS)