CORONARY-ARTERY BYPASS GRAFT-SURGERY IN ONTARIO AND NEW-YORK-STATE - WHICH RATE IS RIGHT

Background: Previous studies have shown that the rate of coronary arte ry bypass graft (CABG) surgery is much higher in New York State than i n Ontario. Objective: To compare the service context and clinical char acteristics of patients having CABG surgery in New York and Ontario. D esign: Retrospective analysis of data from cardiac: surgery registries in New York and Ontario. Patients: All 16 690 patients in New York an d 5517 patients in Ontario who had isolated CABG surgery in 1993. Meas urements: Clinical characteristics of patients having CABG surgery and rates of CABG surgery by coronary anatomy. Results: The overall age-a djusted rate of isolated CABG surgery was 1.79 times (95% CI, 1.74 to 1.85) greater in New York than in Ontario. Patients who had CABG surge ry in New York were more likely to be elderly and female and to have r ecently had myocardial infarction (P < 0.001), whereas patients who ha d CABG surgery in Ontario were more likely to have had left ventricula r dysfunction and severe coronary artery disease (two-vessel disease w ith proximal left anterior descending disease, three-vessel disease, o r left main disease) (P < 0.001). The relative rate of CABG surgery fo r left main disease was 2.53 times (Ci, 2.35 to 2.73) greater in New Y ork than in Ontario but was 8.97 times (CI, 8.01 to 10.06) greater for patients with limited coronary artery disease (one-vessel or two-vess el disease without proximal left anterior descending disease).Conclusi ons: The higher rates of CABG surgery in New York are associated with higher rates of CABG surgery among the elderly, women, and patients wh o recently had myocardial infarction. Potential underservicing in Onta rio is suggested by a lower rate of CABG surgery for left main disease ; however, the higher rate of CABG surgery in New York is also associa ted with a strikingly higher rate of surgery in patients with limited coronary disease. Such trade-offs highlight the difficulty of defining an optimal rate of CABG surgery.