Bill I. Wong

BACKGROUND: Neurological injury is an important cause of morbidity and mortality after cardiac surgery. With the advent of warm heart surgery, the neuroprotective role of hypothermic cardiopulmonary bypass (CPB) has come under increasing scrutiny. Preliminary work by us in the area found no increased risk of neurological morbidity with normothermic CPB in a small group of patients and suggested a possible benefit. The purpose of the present study is to compare the incidence of neurological and neuropsychological dysfunction in a larger number of patients randomized to warm or cold aortocoronary bypass surgery. METHODS AND RESULTS: With the approval of the institutional research ethics committee, 201 aortocoronary bypass patients were randomized to normothermic or moderate hypothermic CPB and subjected to neurological and neuropsychological evaluation. These subjects were a subset of patients enrolled in a large multicenter trial comparing warm versus cold heart surgery. The examinations took place preoperatively, 5 days after operation, and a 3-month follow-up. The examination consisted of a clinical neurological examination and a brief neuropsychological test battery. The neuropsychological tests included the Buschke selective reminding procedure, the Wechsler memory scale-revised visual reproduction subtest, the trial making test (parts A and B), the Wechsler adult intelligence scale-revised digit symbol subtest, and the grooved pegboard test. The examiner and subjects were unaware of the CPB temperature allocation (warm, > 34 degrees C; cold, < or = 28 degrees C). Statistical analysis was performed using the SAS statistical software package. Two hundred one patients were enrolled in the study. Of these, 155 patients completed the entire protocol and were included in the final analysis (warm group, n = 78; cold group, n = 77). One patient in the warm group died perioperatively from a massive hemispheric stroke. Another warm group patient was unable to complete neuropsychological evaluation because of a perioperative stroke. Thus, 153 patients completed the entire series of neuropsychological tests. A total of 6 patients (warm group, n = 2; cold group, n = 4; P = NS) suffered from perioperative focal neurological deficits. There was a consistent deterioration in scores from tests of psychomotor speed/coordination (trial making, digit symbol, pegboard) in the early postoperative period, which resolved by the 3-month follow-up. Tests of memory (Buschke, Wechsler memory scale) showed no evidence of patient deterioration in the postoperative period. No difference was seen between the warm and cold groups. CONCLUSIONS: In this randomized trial of normothermic versus hypothermic CPB, we found deterioration in scores of tests of psychomotor speed but not of memory in the early postoperative period. We were unable to demonstrate any neuroprotective effect from moderate hypothermia in this patient population.

BACKGROUND: This observational study sought to identify the off-label use pattern of recombinant activated factor VII (rFVIIa) in cardiac surgery and to identify predictors of its effectiveness and risk. METHODS AND RESULTS: At 18 Canadian centers, 522 nonhemophiliac cardiac surgical patients received rFVIIa during the period 2003 through 2006; data were available, and retrospectively collected, on 503 patients. The median (quartile 1, quartile 3) units of red blood cells transfused from surgery to therapy and in the 24 hours after therapy were 8 (5, 12) and 2 (1, 5), respectively (P<0.0001). Mortality rate was 32%, and mortality or major morbidity rate was 44%. These rates were within expected ranges (mortality, 27% to 35%; mortality or morbidity, 39% to 48%), which were calculated with a separate cohort of cardiac surgical patients who did not receive rFVIIa used as reference. Independent predictors of complications included instability before therapy (multiple inotropes or intra-aortic balloon pump) and increasing red blood cell units transfused before and after therapy. Variables independently associated with nonresponse included abnormal coagulation parameters and >15 red blood cell units transfused before therapy. CONCLUSIONS: In Canada, rFVIIa is used primarily when standard interventions have failed to control bleeding. In this setting, rFVIIa is associated with reduced blood product transfusions and, after risk adjustment, does not appear to be associated with increased or decreased complication rates. The effectiveness of the drug may be enhanced if it is given early in the course of refractory blood loss in the setting of adequate amounts of circulating coagulation factors.