Prospective evaluation of coronary arteries: influence on operative risk in coronary artery surgery.

OBJECTIVE: Coronary angiography data included in the analysis of operative mortality after coronary artery surgery are generally limited to left main coronary artery stenosis and classification into one-, two- or three-vessel disease, but the role of stenoses and quality of distal runoff on each main coronary artery have never been analysed. The aim of this study was to assess the influence of coronary artery status (stenoses and distal runoff) on operative mortality in patients undergoing coronary artery surgery. METHODS: Stenoses of the five main coronary arteries and their distal runoff were prospectively evaluated in a series of 2461 patients undergoing isolated coronary artery surgery. These angiographic variables were included in analysis of operative mortality in combination with conventional preoperative data. RESULTS: Univariate analysis founded 21 preoperative variables being significant: age >70, body surface area <1.8 m2, arterial disease of lower limbs, history of peptic ulcer, CCS class IV angina, unstable angina, post-infarction unstable angina, congestive heart failure, left ventricular ejection fraction <50%, urgency, preoperative intra-aortic balloon pump, previous myocardial infarction, previous cardiac surgery, previous coronary bypass graft, presence of significant stenosis on the left main coronary artery or the circumflex marginal branch or the distal circumflex artery or the right coronary artery, absence of significant stenosis on the left anterior descending artery, impaired distal runoff on the left anterior descending artery or the circumflex marginal branch (for all, P < 0.05). Multivariate analysis identified poor quality distal runoff in the left anterior descending artery and circumflex marginal branch as independent risk factor (P = 0.0005 and P = 0.04, respectively), while left main coronary artery stenosis was not. This lesion appears to be a significant risk factor only in a small subgroup of patients with CCS class IV angina. Other independent risk factors were CCS class IV angina, previous cardiac surgery, body surface area <1.8 m2, diabetes mellitus, age <70, history of peptic ulcer, left ventricular ejection fraction <50%. Impaired distal runoff or the presence of stenoses on the diagonal branch, right coronary artery, or distal circumflex artery does not significantly influence the operative mortality rate. CONCLUSIONS: The quality of distal runoff of the most frequently grafted vessels is a significant risk factor for operative mortality in coronary artery surgery. Left main coronary artery stenosis was not identified as a risk factor when these angiographic variables were included in the analysis. Functional status remains the most powerful predictive factor.