IMPROVEMENT OF OUTCOMES AFTER CORONARY-ARTERY BYPASS - A RANDOMIZED TRIAL COMPARING INTRAOPERATIVE HIGH VERSUS LOW MEAN ARTERIAL-PRESSURE

Background The objective of this randomized clinical trial of elective coronary artery bypass grafting was to investigate whether intraopera tive mean arterial pressure below autoregulatory limits of the coronar y and cerebral circulations was a principal determinant of postoperati ve complications. The trial compared the impact of two strategies of h emodynamic management during cardiopulmonary bypass on outcome. Patien ts were randomized to a low mean arterial pressure of 50 to 60 mm Hg o r a high mean arterial pressure of 80 to 100 mm Hg during cardiopulmon ary bypass. Methods A total of 248 patients undergoing primary, noneme rgency coronary bypass, were randomized to either low (n = 124) or hig h (n = 124) mean arterial pressure during cardiopulmonary: bypass. The impact of the mean arterial pressure strategies on the following outc omes was assessed: mortality, cardiac morbidity, neurologic morbidity, cognitive deterioration, and changes in quality of life. All patients were observed prospectively to 6 months after the operation. Results The overall incidence of combined cardiac and neurologic complications was significantly lower in the high pressure group at 4.8% than in th e low pressure group at 12.9% (p = 0.026). For each of the individual outcomes, the trend favored the high pressure group. At 6 months after coronary bypass for the high and low pressure groups, respectively, t otal mortality rate was 1.6% versus 4.0%, stroke rate 2.4% versus 7.2% , and cardiac complication rate 2.4% versus 4.8%. Cognitive and functi onal status outcomes did not differ between the groups. Conclusion Hig her mean arterial pressures during cardiopulmonary bypass can be achie ved in a technically safe manner and effectively improve outcomes afte r coronary bypass.