Postoperative N-terminal Pro–Brain Natriuretic Peptide Level in Coronary Artery Bypass Surgery With Ventricular Dysfunction After Perioperative Glucose-Insulin-Potassium Treatment

Cardioprotective Effects of Glucose-Insulin-Potassium Infusion in Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis

The infusion of glucose-insulin-potassium (GIK) has yielded conflicting results in terms of cardioprotective effects. We conducted a meta-analysis to examine the impact of perioperative GIK infusion in early outcome after cardiac surgery. Randomized controlled trials (RCTs) were eligible if they examined the efficacy of GIK infusion in adults undergoing cardiac surgery. The main study endpoint was postoperative myocardial infarction (MI) and secondary outcomes were hemodynamics, any complications and hospital resources utilization. Subgroup analyses explored the impact of the type of surgery, GIK composition and timing of administration. Odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) were calculated with a random-effects model. Fifty-three studies (n=6129) met the inclusion criteria. Perioperative GIK infusion was effective in reducing MI (k=32 OR 0.66[0.48, 0.89] P=0.0069), acute kidney injury (k=7 OR 0.57[0.4, 0.82] P=0.0023) and hospital length of stay (k=19 MD -0.89[-1.63, -0.16] days P=0.0175). Postoperatively, the GIK-treated group presented higher cardiac index (k=14 MD 0.43[0.29, 0.57] L/min P<0.0001) and lesser hyperglycemia (k=20 MD -30[-47, -13] mg/dL P=0.0005) than in the usual care group. The GIK-associated protection for MI was effective when insulin infusion rate exceeded 2 mUI/kg/min and after coronary artery bypass surgery. Certainty of evidence was low given imprecision of the effect estimate, heterogeneity in outcome definition and risk of bias. Perioperative GIK infusion is associated with improved early outcome and reduced hospital resource utilization after cardiac surgery. Supporting evidence is heterogenous and further research is needed to standardize the optimal timing and composition of GIK solutions.

Vitamin D Treatment Attenuates Heart Apoptosis After Coronary Artery Bypass Surgery: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

Vitamin D plays an important role in immune system and in the regulation of inflammatory cytokines. Coronary artery bypass graft (CABG) with cardiopulmonary bypass (CPB) is associated with an extensive inflammatory response. The aim of this study is to examine the effect of vitamin D treatment on the apoptosis and inflammatory changes developed after CABG.

METHODS

This trial was conducted on 70 patients undergoing CABG with CPB. Patients were randomly administered either in placebo or in the group of orally consuming 150 000 IU vitamin D daily for 3 consecutive days before surgery. The right atrium sample was taken to assess caspases 2, 3, and 7 activity using immunohistochemistry method. The serum level of interleukin-10 (IL-10) and insulin-like growth factor 1 (IGF-1) were compared at intervals.

RESULTS

The average number of positive cells for caspases 2 and 3 were less in vitamin D group (P = .006 and P < .001, respectively). There was an increase in serum levels of IL-10 after 3 days from vitamin D treatment before surgery (vitamin D group = 4.4 ± 4.9 ng/mL and control group = 1 ± 0.5 ng/mL, P = .001). After operation, IL-10 increased in both groups, higher level in vitamin D group (P < .001). The comparison of serum IGF-1 showed significant difference after 3 days (P = .006) and remained higher in vitamin D group after CPB (P < .001).

CONCLUSIONS

These findings suggest the apoptosis rate after CPB can be reduced by vitamin D. Vitamin D treatment may improve the inflammatory status before and after surgery. Further studies are needed to confirm the antiapoptotic property of vitamin D and clinical implication.

Hyperinsulinemic Normoglycemia Does Not Meaningfully Improve Myocardial Performance during Cardiac Surgery: A Randomized Trial

BACKGROUND

Glucose-insulin-potassium (GIK) administration during cardiac surgery inconsistently improves myocardial function, perhaps because hyperglycemia negates the beneficial effects of GIK. The hyperinsulinemic normoglycemic clamp (HNC) technique may better enhance the myocardial benefits of GIK. The authors extended previous GIK investigations by (1) targeting normoglycemia while administering a GIK infusion (HNC); (2) using improved echocardiographic measures of myocardial deformation, specifically myocardial longitudinal strain and strain rate; and (3) assessing the activation of glucose metabolic pathways.

METHODS

A total of 100 patients having aortic valve replacement for aortic stenosis were randomly assigned to HNC (high-dose insulin with concomitant glucose infusion titrated to normoglycemia) versus standard therapy (insulin treatment if glucose >150 mg/dl). The primary outcomes were left ventricular longitudinal strain and strain rate, assessed using speckle-tracking echocardiography. Right atrial tissue was analyzed for activation of glycolysis/pyruvate oxidation and alternative metabolic pathways.

RESULTS

Time-weighted mean glucose concentrations were lower with HNC (127 ± 19 mg/dl) than standard care (177 ± 41 mg/dl; P < 0.001). Echocardiographic data were adequate in 72 patients for strain analysis and 67 patients for strain rate analysis. HNC did not improve myocardial strain, with an HNC minus standard therapy difference of -1.2% (97.5% CI, -2.9 to 0.5%; P = 0.11). Strain rate was significantly better, but by a clinically unimportant amount: -0.16 s (-0.30 to -0.03 s; P = 0.007). There was no evidence of increased glycolytic, pyruvate oxidation, or hexosamine biosynthetic pathway activation in right atrial samples (HNC, n = 20; standard therapy, 22).

CONCLUSION

Administration of glucose and insulin while targeting normoglycemia during aortic valve replacement did not meaningfully improve myocardial function.

Level of perioperative B-type natriuretic peptide associates with heart function after on-pump coronary artery bypass graft surgery on a beating heart

Objective:

To explore the relationship of the perioperative B-type natriuretic peptide (BNP) level with heart function among patients undergoing on-pump coronary artery bypass graft surgery on a beating heart.

Methods:

Total 90 patients expected to undergo coronary artery bypass graft surgery were selected and their left ventricular ejection fraction (LVEF) were examined before operation. Patients with LVEF greater than or equal to 50% were selected as the A group (n=46), and those less than 50% formed the B group (n=44). BNP levels of the patients were examined and its relationship with cardiac function was analyzed.

Results:

BNP levels of group A was lower than that in group B pre-and post-operatively (until 7 days after the surgery), the difference is statistically significant (p<0.05). Pearson analysis showed that the BNP level was negatively correlated with the LVEF (r = 0.767, p< 0.05). The area under the Roc curve is 0.865.

Conclusion:

BNP level was negatively correlated with the LVEF. Perioperative BNP level can be used as the prediction for heart function of patients with on-pump coronary artery bypass graft surgery on a beating heart.

The effect of anesthesia method on serum level of pro-brain natriuretic Peptide in patients undergoing orthopedic surgery

Background:

Surgical stress response is among the most severe stress tolerated by the patient, which needs suppression by anesthesia.

Objectives:

We assessed the effect of three methods of anesthesia on postoperative levels of pro-brain natriuretic peptide (pro-BNP) to determine the most effective one in preventing surgical stress response.

Patients and Methods:

In a randomized clinical trial, 120 patients who were 18 to 65 years old and met inclusion and exclusion criteria were selected and randomly allocated to three groups of 40:Group A, general anesthesia plus epidural catheter; Group B, general anesthesia and intravenous patient-controlled analgesia; and Group C, spinal anesthesia plus intravenous patient-controlled analgesia.

Results:

There was no difference between three groups for basic characteristics and variables and baseline pro-BNP levels; however, postoperative pro-BNP levels in Groups A, B, and C were respectively63.8 ± 10.1, 83.2 ± 12.3, and 51.5 ± 8.5 ng/L (ANOVA, P = 0.01).

Conclusions:

The results of the current study suggested that spinal anesthesia plus intravenous patient-controlled analgesia have the most favorable cardiac effects regarding postoperative levels of pro-BNP.