A life table and Cox regression analysis of patients with combined proximal left anterior descending and proximal left circumflex coronary artery disease: non-left main equivalent lesions (CASS).

Abstract

Combined proximal left anterior descending and proximal left circumflex artery stenoses greater than or equal to 70% have been referred to as "left main equivalent" lesions. We compared the survival rates of medically treated patients who have this type of coronary anatomic characteristics with the survival rates of patients who have left main coronary artery stenoses greater than or equal to 70% by use of a stratified life table approach and a Cox regression model. Comparison of the patients with left main coronary artery stenoses with those who have left main equivalent lesions by use of life table analysis and three different calculations of patient exposure time revealed a poorer prognosis for the patients who had left main coronary artery disease (p less than or equal to .04 for all three methods). The stepwise Cox analysis also determined that patients who had left main artery stenoses had a significantly poorer prognosis than patients who had left main equivalent coronary disease (p = .002), even a...