Coronary artery bypass grafting after aprotinin: Are we doing better?

The effect of tranexamic acid on myocardial injury in cardiac surgical patients: a systematic review and meta-analysis

Tranexamic acid (TXA) is one of the most commonly used antifibrinolytic agents for surgical patients. However, the effect of TXA on myocardial injury remains controversial. We systemically reviewed literature regarding the effectiveness of TXA on myocardial injury in patients who have undergone a cardiac surgery. We included all randomized controlled trials (RCTs) comparing TXA and control (saline) in cardiac surgical patients. Relevant studies were identified by a comprehensive electronic literature search from database inception to 15 August 2021. A standardized data extraction form was used to collect methodological and outcome variables from each eligible study. We conducted a meta-analysis to estimate the pooled effect size of TXA administration on myocardial injury. In total, eight RCTs were identified, with 292 patients in the TXA group, and 241 patients in saline or control group. The meta-analysis demonstrated that patients in the TXA group had lower levels of CK-MB and cTnI within 24 h postoperatively (CK-MB: P  = 0.005; cTnI: P  = 0.01), compared with the saline group. No significant difference was found with respect to AST level ( P  = 0.71) between TXA and saline groups within 24 h postoperatively. TXA administration was found to be associated with less myocardial injury among patients who have undergone cardiac surgery. High-quality randomized controlled trials are warranted to further examine the cardioprotective effects of TXA.

Antifibrinolytics and cardiac surgery: The past, the present, and the future

Cardiac surgery is usually associated with significant blood loss, which often necessitates blood transfusion. In order to decrease the risks associated with the latter, pharmacological as well as nonpharmacological strategies have been used to reduce blood loss. Among the pharmacological approaches, antifibrinolytic drugs are the mainstay. Aprotinin, which was the first ubiquitously used drug, fell into disrepute only to re-emerge after much debate. The decline of aprotinin paved the way for the lysine analogs. However, we must be aware with the side effects of these drugs as well as the dose modification required in special situations. Nonsaccharide glycosaminoglycans have been under investigation to overcome the drawbacks of the lysine analogs. It remains to be seen whether these drugs can replace the traditional antifibrinolytics.

Effectiveness and Safety of Aprotinin Use in Thoracic Aortic Surgery

OBJECTIVE

To determine the effectiveness and safety of aprotinin use in adult patients undergoing thoracic aortic surgery.

DESIGN

Single-center, retrospective study.

SETTING

All cases performed at a single university hospital.

PARTICIPANTS

Between January 2004 and December 2014, 846 adult patients underwent thoracic aortic surgery. Due to missing or duplicated data on primary outcomes, 314 patients were excluded. The final sample of 532 patients underwent surgery on the thoracic aorta.

INTERVENTIONS

The patients were divided in the following 2 groups: 107 patients (20.1%) received aprotinin during the surgery, which represented the study group, whereas the remaining 425 patients (79.9%) underwent surgery without the use of aprotinin.

MEASUREMENTS AND MAIN RESULTS

To adjust for patient selection and preoperative characteristics, a propensity score-matched analysis was conducted. Mean total blood loss at 12 hours after surgery was similar between the 2 groups. The blood product transfusion rates did not differ in the 2 groups, except for the rate of fresh frozen plasma transfusion being significantly higher in the aprotinin group. Re-exploration for bleeding and the incidence of a major postoperative bleeding event were similar between the groups. Rates of in-hospital mortality, renal failure, and cerebrovascular accidents did not show any statistically significant difference. Aprotinin did not represent a risk factor for mortality over the long term (hazard ratio 1.14, 95% confidence interval 0.62-2.08, p = 0.66).

CONCLUSIONS

The use of aprotinin demonstrated a limited effect in reducing postoperative bleeding and prevention of major bleeding events. Aprotinin did not adversely affect early outcomes and long-term survival.

Reassessment of Acute Kidney Injury after Cardiac Surgery: A Retrospective Study

Objective To evaluate the incidence, risk, or protective factors of acute kidney injury (AKI) in patients after cardiac surgery based on the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Methods A retrospective analysis of 2,575 patients undergoing their first documented cardiac surgery with cardiopulmonary bypass (CPB) was conducted. Perioperative variables were collected and analyzed. Univariate and multiple logistic regression models were used for determining the association between the development of AKI and risk factors. Multiple Cox-proportional hazards modeling was performed to evaluate the impact of AKI on the mortality in the intensive care unit and hospital length of stay. Results Of 2,575 patients, 931 (36%) developed AKI. A total of 30 (1.2%) patients required renal replacement therapy. In the multivariate analysis, mechanical ventilation duration (OR1.446, 95% CI 1.195-1.749, p<0.001), CPB duration of ≥110 min (OR 1.314, 95% CI 1.072-1.611, p=0.009), erythrocytes transfusion (OR 1.078, 95% CI 1.050-1.106, p<0.001), and postoperative body temperature greater than 38°C within 3 days (OR 1.234, 95% CI 1.018-1.496, p=0.032) were independent risk factors for CSA-AKI, while ulinastatin use was associated with a reduced incidence of CSA-AKI (OR 0.694, 95% CI 0.557-0.881, p=0.006). CSA-AKI was significantly associated with in-hospital mortality (adjusted HR: 2.218, 95% CI 1.161-4.238, p=0.016), especially in patients needing renal replacement therapy (adjusted HR: 18.683, 95% CI 8.579-40.684, p<0.001). Conclusion Mechanical ventilation duration, erythrocytes transfusion, and postoperative body temperature above 38°C within 3 days were considered independent risk factors for CSA-AKI. The use of ulinastatin was associated with a reduced incidence of CSA-AKI.

In-Hospital Outcomes and Complications of Coronary Artery Bypass Grafting in the United States Between 2008 and 2012

OBJECTIVE

To investigate the frequency and predictors of in-hospital complications among patients undergoing coronary artery bypass grafting (CABG) in the United States.

DESIGN

Retrospective national database analysis SETTINGS: United States hospitals.

PARTICIPANTS

A weighted sample of 1,910,236 patients undergoing CABG surgery identified from the National (Nationwide) Inpatient Sample from 2008 to 2012.

INTERVENTIONS

CABG surgery MEASUREMENTS AND MAIN RESULTS: The number of CABG surgeries decreased from 436,275 in 2008 to 339,749 in 2012. The Deyo comorbidity index showed a steady increase from 2008 to 2012. The rate of in-hospital mortality decreased from 2.7% in 2008 to 2.2% in 2012 (p<0.001). The most common in-hospital complication was postoperative hemorrhage (30.4%), followed by cardiac (11.34%) and respiratory complications (2.3%). During the 5-year period, the rates of in-hospital cardiac, respiratory and infectious complications decreased (p<0.001), while the rate of postoperative hemorrhage showed a 35.8% relative increase in 2012 compared to 2008.

CONCLUSION

The annual number of CABG surgeries is declining in the United States. While the burden of comorbidities is increasing, the rates of mortality and most in-hospital complications are improving. The increasing rate of postoperative bleeding necessitates the need to develop strategies to improve the risk of bleeding in this patient population.

The Effect of Intravenous Administration of Active Recombinant Factor VII on Postoperative Bleeding in Cardiac Valve Reoperations; A Randomized Clinical Trial

BACKGROUND

Postoperative bleeding after cardiac reoperations is among the most complicating problems, both for the physicians and for the patients. Many modalities have been used to decrease its adverse effects and the need for blood products administration.

OBJECTIVES

In a randomized double-blinded clinical trial of redo cardiac valve surgery in adult, the effect of active recombinant factor VII (rFVIIa) on postoperative bleeding was compared with placebo. Chest tube drainage was used for comparison of bleeding between the two groups.

PATIENTS AND METHODS

Two groups of 18 patients undergoing redo valve surgeries were treated and compared regarding chest tube drainage, need for blood products, prothrombin time (PT), partial thromboplastin time (PTT), hemoglobin and hematocrit, platelet count, and international normalized ratio (INR) in first 24 hours after surgery. Bleeding was assessed at 3rd, 12th, and 24th hour after operation. In rFVIIa group, 40 µg/kg of AryoSeven was administered before end of surgery and same volume of normal saline was administered as placebo in the control group.

RESULTS

Study groups showed no difference regarding baseline variables. Three patients in rFVIIa group (16.67%) and 13 in placebo group (72.23%) received blood products (P < 0.01). Chest tube blood drainage at 24th hour after operation was 315 ± 177 mL in rFVIIa group and 557 ± 168 mL in control group (P = 0.03). At third and 12th hour after operation, the difference was not statistically significant (P = 0.71 and P = 0.22, respectively). Postoperative ICU stay was not different; while extubation was longer in the placebo group (352 ± 57 vs. 287 ± 46 minutes; P = 0.003).

CONCLUSIONS

Our study demonstrated the efficacy of rFVIIa in controlling postoperative bleeding in redo cardiac valve surgeries regarding subsequent blood loss and transfusion requirement; however, outcome results remains to be defined.

Recent advances on plasmin inhibitors for the treatment of fibrinolysis-related disorders

Growing evidence suggests that plasmin is involved in a number of physiological processes in addition to its key role in fibrin cleavage. Plasmin inhibition is critical in preventing adverse consequences arising from plasmin overactivity, e.g., blood loss that may follow cardiac surgery. Aprotinin was widely used as an antifibrinolytic drug before its discontinuation in 2008. Tranexamic acid and ε-aminocaproic acid, two small molecule plasmin inhibitors, are currently used in the clinic. Several molecules have been designed utilizing covalent, but reversible, chemistry relying on reactive cyclohexanones, nitrile warheads, and reactive aldehyde peptidomimetics. Other major classes of plasmin inhibitors include the cyclic peptidomimetics and polypeptides of the Kunitz and Kazal-type. Allosteric inhibitors of plasmin have also been designed including small molecule lysine analogs that bind to plasmin's kringle domain(s) and sulfated glycosaminoglycan mimetics that bind to plasmin's catalytic domain. Plasmin inhibitors have also been explored for resolving other disease states including cell metastasis, cell proliferation, angiogenesis, and embryo implantation. This review highlights functional and structural aspects of plasmin inhibitors with the goal of advancing their design.

Acute Effect of Intravenous Administration of Magnesium Sulfate on Serum Levels of Interleukin-6 and Tumor Necrosis Factor-α in Patients Undergoing Elective Coronary Bypass Graft With Cardiopulmonary Bypass

Background:

Cardiovascular problems are among the most common health issues. A considerable number of cardiac patients undergo cardiac surgery, and coronary artery disease patients constitute about two-thirds of all these surgeries. The application of cardiopulmonary bypass (CBP) usually results in some untoward effects.

Objectives:

Studies have suggested magnesium sulfate (MgSO4) as an anti-inflammatory agent in a coronary artery bypass graft (CABG). This study aimed to assess the effect of an IV MgSO₄ infusion during elective CABG (with CBP) on the blood levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α).

Materials and Methods:

During a 12 month period, after review board approval and based on inclusion and exclusion criteria, 90 patients were selected and entered randomly into one of the two study groups (MgSO4 or placebo). Anesthesia, surgery and CBP were performed in exactly the same way, except for the use of MgSO4 or a placebo. Both preoperative and postoperative plasma levels of IL-6 and TNF-α were checked and compared between the two groups using an ELISA.

Results:

There was no difference found between the two groups with regard to; gender, basic variables, Ejection Fraction (EF), CBP time and aortic cross-clamp time. The preoperative levels of IL-6 and TNF-α were not different; however, their postoperative levels were significantly higher in the placebo group (P value = 0.01 for IL-6 and 0.005 for TNF-α).

Conclusions:

This study showed that MgSO4 infusion could suppress part of the inflammatory response after CABG with CBP. This was demonstrated by decreased levels of interleukin-6 and TNF-α in postoperative serum levels in elective CABG with CBP.