NEUROLOGIC INJURY IN CARDIAC SURGICAL PATIENTS WITH A HISTORY OF STROKE

Background. Controversy still exists as to whether patients with previ ous stroke are at increased risk for neurologic complications after he art operations. Methods. We performed a prospective analysis of 1,000 consecutive patients undergoing cardiac operations requiring cardiopul monary bypass, without hypothermic circulatory arrest. Of the 1,000 pa tients, 71 had previously documented stroke (study group); 2 control p atients with no history of stroke were selected for each of these pati ents (control group, n = 142). There were no significant differences b etween the study and control patients with respect to established risk factors for neurologic complications. Results. Compared with controls , study patients took longer to awaken (12.6 +/- 10.9 versus 3.5 +/- 2 .1 hours; p < 0.001) and longer to extubate (29.5 +/- 29.3 versus 9.1 +/- 5.2 hours; p < 0.001), and had a greater incidence of reintubation (7 of 71, 9.9% versus 2 of 142, 1.4%; p < 0.01) and postoperative con fusion (26 of 71, 36.6% versus 7 of 142, 4.9%; p < 0.001). There was a higher incidence of focal neurologic deficit among study patients (31 of 71, 43.7% versus 2 of 142, 1.4%; p < 0.001). These deficits includ ed new stroke (6 of 71, 8.5%)) as well as the reappearance of previous deficits (19 of 71, 26.8%) or worsening of previous deficits (6 of 71 , 8.5%), without new abnormalities on head computed tomography or magn etic resonance imaging. Study patients with neurologic deficit had lon ger cardiopulmonary bypass times than did study patients without defic it (146 +/- 48.5 versus 110 +/- 43.3 minutes; p < 0.001). The 30-day m ortality rate was greater in study patients than in controls (5 of 71, 7% versus 1 of 142, 0.7%; p < 0.02), with four deaths among the 6 stu dy patients with a new stroke (66.7%). Conclusion. This analysis ident ifies a group of patients at high risk for neurologic sequelae and con firms the vulnerability of the previously injured brain to cardiopulmo nary bypass, as evidenced by reappearance or exacerbation of focal def icits in such patients.