Multiple electrode whole-blood aggregometry and bleeding in cardiac surgery patients receiving thienopyridines.

BACKGROUND: Preoperative treatment with thienopyridines is associated with increased postoperative bleeding in cardiac surgery patients. Patients under treatment with thienopyridines have different levels of platelet dysfunction and the effects of discontinuation are not totally predictable. The present study aimed to determine if a preoperative assessment of platelet function in these patients could provide clinically relevant information regarding the risks of excessive postoperative bleeding and transfusion requirements. METHODS: This is a retrospective analysis of prospectively collected data. Patients (n=87) under thienopyridine treatment until at least one week before cardiac surgery were enrolled in the study. Platelet function was assessed preoperatively with multiple electrode aggregometry: the adenosine diphosphate (ADP) test and TRAP (thrombin receptor-associated peptide) test were performed for all patients. RESULTS: Univariate analysis revealed that postoperative bleeding was associated (p<0.1) with preoperative serum creatinine level, platelet count, CPB (cardiopulmonary bypass) duration, and results from the ADP test and the TRAP test. Multivariable linear regression analysis confirmed the CPB duration (p=0.049) and ADP test (p=0.007) as independently associated with postoperative bleeding. The relationship between the ADP test and postoperative bleeding was investigated with polynomial regression analysis, and a logarithmic equation provided the best fit. The accuracy of prediction was good (area under the curve 0.71, p=0.013), with a cutoff value for the ADP test at 31 U (sensitivity 72%, specificity 66%, negative predictive value 92%, and positive predictive value 29%). CONCLUSIONS: The multiple electrode aggregometry ADP test in patients under thienopyridine treatment and undergoing cardiac surgery is associated with postoperative bleeding and platelet transfusion and provides an accurate preoperative prediction of postoperative bleeding risk.

Efficacy and safety of recombinant activated factor vii in major surgical procedures: systematic review and meta-analysis of randomized clinical trials.

OBJECTIVE: To investigate the efficacy and safety of recombinant activated factor VII (rFVIIa) treatment in patients undergoing major surgical procedures. DATA SOURCES: Relevant studies were searched in BioMedCentral, CENTRAL, PubMed, and PubMed Central. STUDY SELECTION: Only randomized controlled trials on humans undergoing major surgery were included. Efficacy was determined as the rate of patients receiving allogeneic packed red blood cells; safety was assessed in terms of thromboembolic complications and mortality rate. DATA EXTRACTION: We followed the Cochrane Collaboration method for data extraction and internal validity procedures, as well as the Quality of Reporting of Meta-analyses statement. DATA SYNTHESIS: Seven randomized controlled trials met the inclusion criteria. Treatment with rFVIIa is associated with a reduced risk of receiving allogeneic packed red blood cells (odds ratio, 0.29; 95% confidence interval, 0.10-0.80). In a subgroup analysis, only patients receiving at least 50 mug/kg of rFVIIa had a significant benefit (odds ratio, 0.43; 95% confidence interval, 0.23-0.78). No differences in thromboembolic complications and mortality rates were observed. CONCLUSIONS: Treatment with rFVIIa is effective in reducing the rate of patients undergoing transfusion with allogeneic packed red blood cells. However, the cost-benefit ratio is favorable only in patients who need a huge number of packed red blood cell units. No safety concerns arise from the present study.

Fenoldopam prophylaxis of postoperative acute renal failure in high-risk cardiac surgery patients.

BACKGROUND: Acute renal failure requiring replacement therapy occurs in 1% to 2% of patients who have undergone cardiac surgery with cardiopulmonary bypass and is associated with a very high mortality rate. The aim of this study was to determine if prophylactic treatment with fenoldopam mesylate of patients at high risk of postoperative acute renal failure reduced the incidence of this event. METHODS: This was a multicenter, prospective, cohort study in which 108 patients at high risk of postoperative acute renal failure and undergoing cardiac surgery with cardiopulmonary bypass were treated with fenoldopam mesylate (0.08 microg x kg(-1) x min(-1)) starting at the induction of anesthesia and throughout at least the next 24 hours. A homogeneous control group of 108 patients was created using a propensity-score analysis. RESULTS: Fenoldopam prophylaxis was significantly associated with a reduction in acute renal failure incidence (from 22% to 11%, p = 0.028), a less pronounced creatinine clearance decrease (p = 0.05), and a lower mortality rate (6.5% versus 15.7%, p = 0.03) by the univariate analysis, but these results were not confirmed by a multivariable analysis. Within the subgroup of patients who suffered a postoperative low output syndrome, fenoldopam prophylaxis was an independent protective factor for postoperative renal failure (odds ratio, 0.14; 95% confidence interval, 0.03 to 0.7; p = 0.017). CONCLUSIONS: Given the limitations of a nonrandomized prospective trial, our results support the hypothesis that fenoldopam may reduce the risk of acute renal failure in patients in whom endogenous and exogenous cathecolamines action may induce a renal vascular constrictive condition.

The antithrombin III-saving effect of reduced systemic heparinization and heparin-coated circuits.

OBJECTIVE: To investigate the perioperative changes of antithrombin III (AT-III) activity using reduced systemic heparinization and the possible role of AT-III in determining a better postoperative outcome. DESIGN: Prospective randomized study. SETTING: University hospital. PARTICIPANTS: Patients undergoing elective coronary revascularization with cardiopulmonary bypass (n = 90). INTERVENTIONS: Of patients, 30 were treated with heparin-coated circuits and reduced systemic heparinization; 30, with heparin-coated circuits and full systemic heparinization; 30, with conventional circuits and full systemic heparinization. MEASUREMENTS AND MAIN RESULTS: Heparin-coated circuits with full systemic heparinization did not exert any effect on coagulation parameters. Low systemic heparinization resulted in a significantly (p < 0.01) higher hematocrit value on arrival in the intensive care unit and in significantly higher values of AT-III activity during cardiopulmonary bypass (66 +/- 12% v 57.4 +/- 13% and 59.1 +/- 12% in the full systemic heparinization groups; p < 0.05), on arrival in the intensive care unit (69.7 +/- 13% v 60.7 +/- 13% and 60.8 +/- 11% in the full systemic heparinization groups; p < 0.01), and on the first postoperative day (81.3 +/- 15% v 67.4 +/- 13% and 70.2 +/- 12% in the full systemic heparinization groups; p < 0.01). No differences were observed in the clinical outcome. CONCLUSION: Reducing systemic heparinization determines an AT-III-saving effect that could be responsible for the decrease in thromboembolic complications already observed by other authors. It induces higher hematocrit levels immediately after the operation, probably reducing the unmeasurable intraoperative blood loss.