Aprotinin and the risk of death and renal dysfunction in patients undergoing cardiac surgery: a meta-analysis of epidemiologic studies

Multicenter International Survey on Cardiopulmonary Bypass Perfusion Practices in Adult Cardiac Surgery

OBJECTIVES

To assess current practice in adult cardiac surgery during cardiopulmonary bypass (CPB) across European and non-European countries.

DESIGN

International, multicenter, web-based survey including 28 multiple choice questions addressing hemodynamic and tissue oxygenation parameters, organ protection measures, and the monitoring and usage of anesthetic drugs as part of the anesthetic and perfusion practice during CPB.

SETTING

Online survey endorsed by the European Association of Cardiothoracic Anesthesiologists.

PARTICIPANTS

Representatives of anesthesiology departments in European and non-European adult cardiac surgical centers.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The survey was distributed via e-mail to European Association of Cardiothoracic Anesthesiologists members (n = 797) and kept open for 1 month. The response rate was 34% (n = 271). After exclusion of responses from the same centers and of incomplete answers, data from 202 cardiac centers in 56 countries, of which 67% of centers were university hospitals, were analyzed. Optimization of pump flows and tissue oxygenation parameters during CPB were applied by the majority of centers, with target flow rates of >2.2 L/min/m² in 93% (n = 187) of centers and mean arterial blood pressures between 51 and 90 mmHg in 85% (n = 172). Hemoglobin transfusion triggers were either individualized or between 7 and 8 g/dL in 92% (n = 186) of centers. Mixed venous oxyhemoglobin saturations were assessed routinely in 59% (n = 120) and lactate in 88% (n = 178) of cardiac surgery units. Noninvasive cerebral saturation monitoring was used in a subgroup of patients or routinely in 84% (n = 169) of sites, and depth-of-anesthesia monitoring was used routinely in 53% (n = 106). Transesophageal echocardiography and pulmonary artery catheters were used routinely or in subgroups of patients in 97% (n = 195) and 71% (n = 153) of centers, respectively. The preferred site for temperature monitoring was the nasopharynx in 66% (n = 134) of centers. Anesthetic techniques were variable, with 26% of centers (n = 52) using low-tidal-volume ventilation and 28% (n = 57) using continuous positive airway pressure during CPB. Volatile agents were used routinely as the only agent during CPB in 36% sites (n = 73) and propofol in 47% (n = 95). Other drugs routinely administered included magnesium in 45% (n = 91), steroids in 18% (n = 37), tranexamic acid in 88% (n = 177), and aprotinin in 15% (n = 30) of the centers.

CONCLUSION

This international CPB survey revealed that techniques for optimization of pump flow and oxygenation during CPB usually were applied. Furthermore, cerebral and hemodynamic monitoring devices were frequently used during CPB. However, most CPB-related anesthetic techniques and medications were more variable. More high-quality randomized controlled trials are needed to assess anesthetic techniques and organ protection.

Increased perioperative mortality following aprotinin withdrawal: a real-world analysis of blood management strategies in adult cardiac surgery

PURPOSE

To evaluate the effect of aprotinin withdrawal in 2008 on patient outcomes, to assess the likely risks and benefits of its re-introduction, and to consider the relevance of existing evidence from clinical trials to 'real-world' practice.

METHODS

We performed a nested case-control study of two cohorts undergoing adult cardiac surgery in a single tertiary centre. The first group underwent surgery between 1 January 2005 and 30 July 2007 (n = 3,578), prior to aprotinin withdrawal; the second group underwent surgery between 1 January 2009 and 31 December 2010 (n = 3,030), after aprotinin withdrawal. Propensity matching was used to select patients matched for 24 covariates in both groups (n = 3,508). We also estimated the effect of aprotinin withdrawal on a subgroup of high-risk patients (n = 1,002). Results were expressed as adjusted odds ratios (OR) and 95% confidence intervals (CI) for categorical data and hazard ratios (HR) for time-to-event data.

RESULTS

In propensity-matched cohorts, the withdrawal of aprotinin from clinical use was associated with more bleeding, higher rates of emergency re-sternotomy, OR 2.10 (1.04-4.25), and acute kidney injury (AKI), OR 1.86 (1.53-2.25). In high-risk patients, the increases in bleeding and AKI following aprotinin withdrawal were of a greater magnitude. Aprotinin withdrawal was also associated with a significant increase in 30-day mortality, HR 2.51 (1.00-6.29), in the high-risk group. The results were not altered by sensitivity analyses that adjusted for potential selection bias, time series bias and unmeasured confounders.

CONCLUSIONS

Aprotinin withdrawal was associated with increased complication rates and patient deaths following cardiac surgery. These real-world findings are at odds with those of randomised trials and cohort studies that have considered the clinical role of aprotinin.

Retrospective cohort analysis of a single dose of aprotinin use in children undergoing cardiac surgery: a single-center experience

OBJECTIVES

The great difference in side effects of aprotinin was noted in adult and pediatric fields in recent reports because aprotinin was suspended for safety reasons. The aim of this study is to describe associations between aprotinin using and red blood cells transfusion, renal injury, and mortality in pediatric with cardiac surgery.

METHODS

We retrospectively reviewed a cohort of 507 consecutive children who received a single dose of aprotinin (March-November 2007 before the FDA's decision for withdrawal of aprotinin) and a cohort of 494 consecutive children who did not receive aprotinin or other antifibrinolytic drugs (December 2007-August 2008).

RESULTS

The two groups' demographics were assessed by the Aristotle basic complexity (ABC) propensity score. Postoperative blood loss was significantly reduced in the aprotinin group [P < 0.001, 95% confidence intervals (CI): 0.00-0.00], but postoperative red blood cell transfusion was not different between two groups (P = 0.4, 95% CI: 0.393-0.412). No statistical significant differences were noted in postoperative dialysis [0.39% vs. 0.40%, P = 0.98, OR: 0.974, 95% CI: 0.137-6.944] and intra-hospital mortality (2.37% vs. 1.82%, P: 0.547, OR:1.306, 95% CI: 0.546-3.129)) and reoperations for bleeding, thrombotic, and respiratory morbidity between two groups; however, the aprotinin group had temporarily a higher rate of 1.5-fold increased creatinine (class R) in the first postoperative 72 h (22.95% vs. 13.93%, P < 0.001, OR: 1.840, 95% CI: 1.323-2.560), a longer duration of mechanical intubation [6.50 (4.50-24.00) h vs. 6.00 (4.50-22.00) h, P = 0.004, 95% CI: 0.002-0.005] and a 0.55% increased clinical mortality (although not statistically significant). More complex surgery had a higher rate of the increased creatinine (class R) in the first postoperative 72 h (ABC level 3 + 4 vs. level 1 + 2, P = 0.017, OR: 0.599, 95% CI: 0.392-0.915). The multivariate analysis showed that age (<1 year), CPB >100 min, and the larger amount of transfusion (≥14 ml·kg(-1) ) were also important risk factors for the postoperative renal dysfunction (class R).

CONCLUSIONS

Except reducing postoperative bleeding, we did not find other benefits of aprotinin. However, much higher postoperative creatinine levels, longer duration of mechanical ventilation, not less postoperative RBCs transfusion, and a 0.55% increased clinical mortality (although not statistically significant) were found in the aprotinin populations.

Aprotinin, transfusions, and kidney injury in neonates and infants undergoing cardiac surgery

BACKGROUND

A significantly increased risk of acute kidney injury (AKI) with the prophylactic use of aprotinin has been reported in adults undergoing cardiac surgery, but not in children. Blood product transfusions have also been shown to carry an independent risk of AKI. The present study assessed associations between AKI, aprotinin, and transfusions in neonates and infants undergoing cardiac surgery.

METHODS

All neonates and infants undergoing surgery with cardiopulmonary bypass over a 42 month period, before and after the withdrawal of aprotinin, were included retrospectively. AKI was assessed by the Acute-Kidney-Injury-Network classifications. A propensity score was used to balance treated and untreated groups.

RESULTS

Three hundred and ninety patients received aprotinin and 568 patients did not. Inverse probability of treatment weighting resulted in good balance between groups for baseline and surgical characteristics. Controls underwent surgery with smaller bypass circuits and fewer transfusions. After adjustment for the use of miniaturized circuits and for the year of surgery, no significant association between the incidence of AKI, dialysis, and aprotinin was noted. Red blood cell transfusions were associated with an increased risk of AKI and dialysis: odds ratios (ORs) 1.64 (1.12-2.41) and 2.07 (1.13-3.73), respectively; as were fresh frozen plasma transfusions, ORs 2.28 (1.68-3.09) and 3.11 (1.95-4.97), respectively. Platelet transfusions were associated with an increased risk of dialysis: OR 2.20 (1.21-4.01).

CONCLUSIONS

Blood product transfusions, but not the prophylactic use of aprotinin, are significantly associated with AKI after cardiac surgery in neonates and infants.

Nafamostat mesilate attenuates Postreperfusion Syndrome during liver transplantation

Postreperfusion syndrome (PRS), an acute decrease in blood pressure after reperfusion of the liver graft, occurs frequently during liver transplantation surgery. We supposed that the activation of the kallikrein-kinin system leading to extensive systemic vasodilatation was a possible cause. The effect of pretreatment with nafamostat mesilate (NM), a broad spectrum serine protease inhibitor, on the occurrence of PRS was evaluated. Sixty-two adult liver recipients were randomized to receive an intravenous bolus of either 0.02 mg/kg of NM (NM group, n = 31) or an equal volume of normal saline (control group, n = 31) just before reperfusion of the liver graft. Occurrence of PRS and intraoperative use of vasoactive drugs were compared between the two groups. Postoperative recovery was also compared. PRS was significantly less frequent (48% vs. 81%, p = 0.016) requiring less vasopressors in the NM group compared to the control group. The NM group also showed faster recovery of the mean arterial pressure. Perioperative laboratory values were similar between the two groups. Pretreatment with 0.02 mg/kg of NM immediately before reperfusion decreases the frequency of PRS and vasopressor requirements during the reperfusion period in liver transplantation.

Blood loss in major spine surgery: are there effective measures to decrease massive hemorrhage in major spine fusion surgery?

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the definition and incidence of significant hemorrhage in adult spine fusion surgery, and to assess whether measures to decrease hemorrhage are effective.

SUMMARY OF BACKGROUND DATA

Significant hemorrhage and associated comorbidities in spine fusion surgery have not yet been clearly identified. Several preoperative and intraoperative techniques are currently available to reduce blood loss and transfusion requirements such as cell saver (CS), recombinant factor VIIa, and perioperative antifibrinolytic agents, such as aprotinin, tranexamic acid, and epsilon-aminocaproic acid. Their effectiveness and safety in spine surgery is uncertain.

METHODS

A systematic review of the English-language literature was undertaken for articles published between January 1990 and April 2009. Electronic databases and reference lists of key articles were searched to identify published studies examining blood loss in major spine surgery. Two independent reviewers assessed the quality of the literature using the Grading of Recommendations Assessment, Development, and Evaluation criteria. Disagreements were resolved by consensus.

RESULTS

A total of 90 articles were initially screened, and 17 ultimately met the predetermined inclusion criteria. No studies were found that attempted to define significant hemorrhage in adult spine surgery. We found that there is a high level of evidence that antifibrinolytic agents reduce blood loss and the need of transfusion in adult spine surgery; however, the safety profile of these agents is unclear. There is very low evidence to support the use of CS, recombinant factor VIIa, activated growth factor platelet gel, or normovolemic hemodilution as a method to prevent massive hemorrhage in spine fusion surgery.

CONCLUSION

There is no consensus definition of significant hemorrhage in adult spine fusion surgery. However, definition in the anesthesiology literature of massive blood loss is somewhat arbitrary but is commonly accepted to entail loss of 1 volume of the patient's total blood (60 mL/kg in adults) in <24 hours. On the basis of the current literature, there is little support for routine use of CS during elective spinal surgery. Concerns related to the use of aprotinin were such that our panel of experts unanimously recommended against its use in spine surgery on the basis of the reports of increased complications. With respect to the antifibrinolytics of the lysine analog class (tranexamic acid and aminocaproic acid), on the basis of the available efficacy and safety data, we recommend that they be considered as possible agents to help reduce major hemorrhage in adult spine surgery.

2010 Young Investigator Award winner: Therapeutic aprotinin stimulates osteoblast proliferation but inhibits differentiation and bone matrix mineralization

STUDY DESIGN

Analysis of the effect of antifibrinolytics on in vitro bone formation.

OBJECTIVE

As the direct effect of antifibrinolytics on bone formation is unknown, we examined whether antifibrinolytics routinely used in spine surgery, namely, aprotinin and aminocaproic acid, affect osteoblast function in vitro.

SUMMARY OF BACKGROUND DATA

Antifibrinolytics are used in spine surgery to prevent intraoperative blood loss and decrease the need for transfusion. They are either delivered systemically or included as a component of most tissue sealants. Although the role of the fibrinolytic system in wound healing is well established, reports of indirect effects on normal bone biology are emerging. This suggests that the pharmacological targeting of this system may also influence skeletal mass and integrity.

METHODS

Osteoblast progenitor cells were cultured with therapeutic doses of aprotinin and aminocaproic acid. The effect of the antifibrinolytics on osteoblast development was determined by measuring cellular viability and proliferation, quantification of matrix mineralization, and genetic analysis of osteoblast differentiation markers. Protease inhibition profiles of the antifibrinolytics were determined by amidolytic chromogenic assays.

RESULTS

Therapeutic concentrations of aprotinin dose-dependently inhibited plasmin's proteolytic activity, stimulated osteoblast proliferation, and inhibited osteoblast differentiation and matrix mineralization. Aprotinin inhibition of osteoblast differentiation and matrix mineralization could be recovered by removing aprotinin from culture or stimulating cells with bone morphogenetic protein-2 or plasmin. Conversely, aminocaproic acid inhibited plasmin's proteolytic activity significantly less than aprotinin and had no effect on osteoblast proliferation, differentiation, or matrix mineralization in its therapeutic range.

CONCLUSION

These findings demonstrate that the antifibrinolytics have drastically different effects on osteoblasts due in part to different efficacies of protease inhibition. Further, this work suggests that the fibrinolytic proteases and their inhibitors have great potential to regulate bone by affecting the processes that control osteoblast growth and differentiation.

Anti-inflammatory drugs and risk of Parkinson disease: a meta-analysis

BACKGROUND/OBJECTIVE

Anti-inflammatory drugs may prevent Parkinson disease (PD) by inhibiting a putative underlying neuroinflammatory process. We tested the hypothesis that anti-inflammatory drugs reduce PD incidence and that there are differential effects by type of anti-inflammatory, duration of use, or intensity of use.

METHODS

MEDLINE and EMBASE were searched for studies that reported risk of PD associated with anti-inflammatory medications. Random-effects meta-analyses were used to pool results across studies for each type of anti-inflammatory drug. Stratified meta-analyses were used to assess duration- and intensity-response.

RESULTS

Seven studies were identified that met the inclusion criteria, all of which reported associations between nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) and PD, 6 of which reported on aspirin, and 2 of which reported on acetaminophen. Overall, a 15% reduction in PD incidence was observed among users of nonaspirin NSAIDS (relative risk [RR] 0.85, 95% confidence interval [CI] 0.77-0.94), with a similar effect observed for ibuprofen use. The protective effect of nonaspirin NSAIDs was more pronounced among regular users (RR 0.71, 95% CI 0.58-0.89) and long-term users (RR 0.79, 95% CI 0.59-1.07). No protective effect was observed for aspirin (RR 1.08, 95% CI 0.92-1.27) or acetaminophen (RR 1.06, 95% CI 0.87-1.30). Sensitivity analyses found results to be robust.

CONCLUSIONS

There may be a protective effect of nonaspirin nonsteroidal anti-inflammatory drug use on risk of Parkinson disease (PD) consistent with a possible neuroinflammatory pathway in PD pathogenesis.