Do the presence and amount of dysfunctional but viable myocardium affect the perioperative outcome of coronary artery bypass graft surgery?

The aim of our study was to assess the influence of the presence and amount of dysfunctional but viable myocardium on the perioperative outcomes in pa tients with coronary artery disease and moderate-to-seven left ventricular systolic dysfunction, who underwent coronary artery bypass graft surgery. V iability evaluation with low-dose dobutamine echocardiography was performed in 302 consecutive patients with coronary artery disease and left ventricu lar ejection fraction less than or equal to 40%, who were referred for coro nary angiography and potential coronary revascularization. To quantify the amount of dysfunctional but viable myocardium, wall motion was scored using a 16-segment model. The dysfunctional segments were defined as viable if t hey exhibited improvement in their thickening by at least one grade. One hu ndred and twenty-seven patients underwent coronary artery bypass graft surg ery. The perioperative outcomes were evaluated in 122 of them. Five patient s were excluded because of inability to revascularize all vessels supplying dysfunctional but viable myocardial segments. Twenty-five patients exhibit ed a large amount of dysfunctional but viable myocardium (greater than or e qual to 6 segments, group A), 59 patients had a small amount of such myocar dium (2-5 segments, group B), and 38 patients were found to have their dysf unctional myocardium irreversibly damaged (group C). The perioperative mort ality in groups A, B, and C was 4, 10, and 11% (all P = NS), respectively. The rate of perioperative Q-wave myocardial infarction was 8, 10, and 3% (a ll P = NS), respectively. Similarly,there were no significant differences a mong the groups with respect to perioperative outcome variables including v entricular arrhythmias, duration and magnitude of catecholamine support, re nal failure, pulmonary edema, and need for mechanical ventricular support o r artificial ventilation. In patients with coronary artery disease and mode rate-to-severe left ventricular dysfunction who underwent coronary artery b ypass graft surgery, the presence and amount of dysfunctional but viable my ocardium did not influence the perioperative outcome. (C) 1999 Elsevier Sci ence Ireland Ltd. All rights reserved.