Internal mammary artery bypass grafting in patients with poor left ventricular ejection fraction

Todate internal mammary artery (IMA) is routinely used in coronary artery b ypass grafting even in elder patients. However in patients with poor left v entricular function use of the IMA is discussed controversely in Germany. M ain arguments against IMA are an increased operation time, initially lower blood now, higher rates of reoperation for bleeding and more perioperative complications. In this study we investigated use of the IMA in patients wit h poor left ventricular function (LVEF < 40 %) compared to exclusively vein graft bypass surgery. 137 patients (105 m/32 f) suffering from coronary art ery disease with reduced LVEF (12-40 %) were randomized in the study. 67 pa tients received exclusively vein grafts (group I), 70 patients routinely ob tained an IMA graft. Criteria used for evaluation of IMA graft were operati on time, postoperative bleeding, need for catecholamines, requirement of in tensive care, perioperative myocardial infarction and mortality. The number of distal anastomoses in each group was 3.1 (2-5). The operation time vari ed in compliance with the number of distal anastomoses, but there were no s ignificant differences between both groups. Postoperative bleeding until th e second postoperative day was 905 mi in group II versus 569 mi in group I; the difference was significant (p < 0.05). The need of catecholamines afte r operation and hemodynamic parameters were comparable in both groups, ther e were no significant differences. Intensive care was required for a mean o f 1.6 days in both groups, postoperative ventilation was 5.8 hours in group I versus 7.9 hours in group II, differences not significant. Ischemia or m yocardial infarction could be demonstrated in 2 patients of group I (3 %) v ersus 4 patients of group II (5.7 %). The differences between the groups we re not significant. Cardiac low output syndromes without sights of myocardi al infarction were apparent in 9 patients of group I (13.5 %) versus 2 pati ents of group II (2.9 %), this difference being significant (p < 0.05). Mor tality after operation in both groups was higher than in patients with norm al ventricular function, however the differences between the evaluated grou ps were not significant (5.9 % in group I versus 4.3 % in group II). Summar izing the above it can be concluded that patients with poor left Ventricula r function are at a higher risk when subjected to bypass operation; the use of IMA did not show any disadvantages in comparison to exclusively veingra ft surgery, except of a higher perioperative bleeding risk. Due to better l ong term results IMA should be used routinely also in bypass-patients with poor left ventricular function.