Cardiothoracic
Oxidative stress in patients undergoing cardiac surgery: comparative study of revascularization and valve replacement procedures

https://doi.org/10.1016/S0022-4804(03)00106-9Get rights and content

Abstract

Objective. The aim of this study was to evaluate the time course of oxidative stress markers in plasma and erythrocyte from patients undergoing open heart surgery with cardiopulmonary bypass (CPB) and to examine whether the type of surgical technique used (valve replacement or coronary revascularization) produces any differences in these makers.

Patients and methods. Twenty-two patients undergoing cardiac surgery with CPB were divided in 2 groups (valve replacement or coronary revascularization). We took 5 blood samples at different times during cardiac surgery and analyzed thiobarbituric acid reactive substances (TBARS), α-tocopherol, coenzyme Q, and retinol in plasma and TBARS (baseline levels and induced by Fe2+-ascorbate oxidation), α-tocopherol, coenzyme Q and catalase, superoxide dismutase, and glutathione peroxidase activity in erythrocyte.

Results. Plasma α-tocopherol content decreased after starting CPB in both groups. In contrast, in erythrocytes there was an increase in the activity or concentration of all of the antioxidants. Erythrocyte TBARS contents, both baseline levels and induced levels, were higher in coronary revascularization group.

Conclusion. Although both groups suffered an increase in oxidative stress after CPB, this increase was higher in coronary revascularization group and therefore the possibility of post-CPB complications could be more severe in this group. As the groups followed a different pattern of antioxidant response, a different therapeutic approach may be required for each.

Introduction

An ever-increasing number of patients are undergoing cardiac surgery, involving either coronary revascularization or the replacement of heart valve structures (valve replacement) 1, 2. Both surgical procedures normally require the use of cardiopulmonary bypass (CPB) 1, 2.

It is known that CPB patients are subjected to a high degree of surgical risk 1, 2, 3, 4. In addition to the unphysiological hemodynamic conditions, one complication that may occur during CPB is the ischemia-reperfusion syndrome 3, 5, 6. During this syndrome, functional, structural and metabolic alterations are caused by a number of factors, one of which is the continuous generation of free radicals arising, among other causes, from the introduction of oxygen during reperfusion 3, 5, 6. The free radicals produced during CPB give rise to lipid peroxidation, thus damaging the cell membrane [7].

Free radicals are considered a factor responsible for systemic inflammation, one of the most significant aspects of the harmful effects of CPB and which may contribute to the development of several postoperative complications. According to some authors, free radicals are also responsible for causing reperfusion-derived arrhythmias and myocardial alteration 8, 9.

Valve replacement and coronary revascularization patients follow a similar intraoperatory procedure 1, 2, so it can be considered that both type of patients are under a similar degree of damage. However, in each group, patients present a distinct physiopathology and therefore they had different medical treatment and different associated pathologies 1, 2, which could change the response against a similar damage. This aspect has been poorly studied.

The aim of this study was to evaluate the time course of oxidative stress markers in plasma and erythrocyte from patients undergoing open heart surgery with cardiopulmonary bypass and, to examine whether the type of surgical procedure used (valve replacement or coronary revascularization) produces any differences in these makers.

Section snippets

Patients

To conduct this study, we selected 22 white male patients living in Southern Spain and considered to present a high/severe level of surgical risk, according to the Pettigrew scale, which incorporates several different indicators of the risk of surgery [10]. The patients were divided into 2 groups depending on the type of surgical intervention, the fundamental characteristics of the disease and the physicopathological problems presented (n = 11 per group). These groups comprised: 1) patients

Results

No surgery or anesthesia-related complication arose during this study. Plasma antioxidants (coenzyme Q, α-tocopherol, and retinol) are shown in Table 2. In general, a similar pattern was presented for both studied groups. Nevertheless, differences were observed between the two groups, especially with respect to the content of α-tocopherol. Thus, patients subjected to coronary revascularization presented higher α-tocopherol concentrations with statistically significant difference (P < 0.05) at

Discussion

In this study, as shown in the clinical characteristics of the patients, the groups are fairly homogeneous in composition and do not present significant differences concerning the surgical procedure in itself. The two groups were subjected to a similar degree of stress, as the intraoperatory procedure was comparable 1, 2. However, it should be noted that these patients presented different pathologies and thus received different medical treatments. This consideration could affect the organism’s

References (26)

  • R. Bolli

    Oxygen-derived free radicals and myocardial reperfusion injury—an overview

    Cardiovasc.Drugs Ther.

    (1991)
  • J. Vaage et al.

    Physiology and mediators of ischaemia-reperfusion injury with special reference to cardiac surgery

    Scand. J. Thor. Cardiovasc. Surg.

    (1993)
  • P.A. Grace

    The injury caused by the sequence ischaemia reperfusion

    Scand. J. Thor. Cardiovasc. Surg.

    (1995)
  • Cited by (17)

    • Effects of limb revascularization procedures on oxidative stress

      2018, Journal of Surgical Research
      Citation Excerpt :

      This may explain the greater risks of cardiovascular outcomes, including mortality, which has been reported for PAD patients undergoing limb revascularizations.7 Increases in oxidative stress have been reported after coronary revascularization, and this has been suggested to potentially lead to more severe postprocedure complications.21,22 Less is known about how oxidative stress may play a role in limb revascularization procedures.

    • Effects of Left Ventricular Assist Device (LVAD) Placement on Myocardial Oxidative Stress Markers

      2012, Heart Lung and Circulation
      Citation Excerpt :

      There are many possible cellular mechanisms to explain the lack of change in oxidative stress levels following LVAD placement. As shown by Ochoa et al. [37], open heart surgery will acutely increase the levels of oxidative stress in the blood. In the present study, tissue was collected during open heart surgery which may have caused further increases in the myocardial oxidative stress, but both tissue samples should have equal amount of increased oxidative stress from surgery.

    • Renal Failure After Cardiac Surgery: Timing of Cardiac Catheterization and Other Perioperative Risk Factors

      2007, Annals of Thoracic Surgery
      Citation Excerpt :

      Cardiac surgery, and cardiopulmonary bypass in particular, are associated with significant physiologic oxidative stress. This stress is related to ischemia-reperfusion processes which, in addition to generating reactive oxygen species, are also associated with a state of systemic inflammation that may contribute to postoperative organ dysfunction, including renal failure [18, 19]. N-acetylcysteine is a nonspecific antioxidant and vasodilator that functions as an oxygen free-radical scavenger.

    View all citing articles on Scopus
    View full text