EVALUATION OF PREOPERATIVE INTRAAORTIC BALLOON PUMP SUPPORT IN HIGH-RISK CORONARY PATIENTS

Objective: The intra-aortic balloon pump (IABP) is an established addi tional support to pharmacological treatment of the failing heart after myocardial infarction, unstable angina and cardiac surgery. The effec t of preoperative IABP in high risk patients was evaluated. Methods: B etween June 1994 and March 1996 all high risk patients for CABG (two o r more of these criteria: Left ventricular ejection fraction (LVEF) le ss than or equal to 40%, left main stem stenosis greater than or equal to 70%, REDO-CABG, unstable angina) were randomized into either of 3 groups: (1) IABP 1 day prior to surgery, (2) IABP 1-2 h prior to CPB a nd (3) no preoperative IABP, controls. Exclusion criteria: cardiogenic shock preoperatively. Fifty-two patients have entered the study-group 1 (13 patients), group 2 (19 patients) and group 3 (20 patients). Pre operative patient characteristics and operative data revealed no group differences. There were 56% REDO's, unstable angina 59%, LVEF less th an or equal to 40%, 87% (34.0 +/- 11.6%) and left main stem stenosis i n 35%. Results: The CPB-time was shorter in groups 1 and 2 88.7 +/- 20 .3 min than in group 3 105.5 +/- 26.8 min, P < 0.001, while ischemia t ime did not differ. Hospital mortality was higher in group 3, 25% vs. 6% (groups 1 and 2). Postoperative low cardiac output was seen in 12 p atients (60%) in group 3 vs. 6 patients (19%) in groups 1 and 2, P < 0 .05. Cardiac index increased significantly prior to CPB in groups 1 an d 2. After CPB cardiac index was significantly higher in groups I and 2 compared to Group 3 and continued to increase. The IABP was removed after 3.1 +/- 1.0 days in group 3 vs. 1.3 +/- 0.6 days in groups 1 and 2, P < 0.001. In group 3, 11 patients required IABP postoperatively c ompared to only 4 patients in groups 1 and 2. ICU stay was shorter in groups 1 and 2-2.3 +/- 0.9 days vs. 3.5 +/- 1.1 days for group 3, P = 0.004. All patients received dopamin postoperatively, however in a low er dose in groups 1 and 2, 4.5 vs. 13.5 mu g/kg/min. Dobutamine was ad ded in 23% of the patients (group 1), 32% (group 2) and 95% (group 3). Adrenalin/amrinonum was required in 40% of the patients in group 3, 5 % in group 2 and none in group 1. Group I patients had a better improv ement of cardiac performance than group 2, while other parameters did not differ. Three months follow up of hospital survivors showed no gro up differences. Conclusions: The use of preoperative IABP in high risk patients lowers hospital mortality and shortens the stay in ICU, due to improved cardiac performance, compared to a controls. The procedure was cost-beneficial. One day preoperative IABP treatment improves car diac performance more than 1-2 h preoperative IABP treatment, but does not significantly affect the outcome in terms of hospital mortality o r postoperative morbidity. (C) 1997 Elsevier Science B.V.