Effect of esmolol on oxidant status and antioxidant activity in acute myocardial infarction.
OBJECTIVE
The role of oxygen free radicals in reperfusion injury to the heart in myocardial infarction (MI) has been postulated. In this study, the clinical and antioxidant effects of esmolol, an ultra-short acting beta blocker in patients of acute MI was studied.


METHODS
This was a randomized, double-blind, controlled, prospective study. Total 30 patients with acute MI were included. All patients were thrombolysed with streptokinase. Fifteen of these patients were randomly selected to receive esmolol while other 15 patients served as controls. The parameters compared at 0, 2 and 24 hours between the esmolol group and the controls were--malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX).


RESULTS
Patients with MI had 5.16 times higher MDA level at 0 hours (20.34 +/- 6.12 nmol/ml vs. 3.94 +/- 0.70 nmol/ml, p < 0.0001) than MDA level in normal healthy population. At 2 hours, patients with MI had 5.71 times higher MDA level compared to normal healthy population (22.51 +/- 5.51 nmol/ml vs. 3.94 +/- 0.70 nmol/ml, p < 0.0001). A statistically significant difference in MDA levels at 2 and 24 hours was observed in MI patients given esmolol (mean change 2.06 +/- 5.39 nmol/ml vs. -4.47 +/- 6.93 nmol/ml, p = 0.009). Esmolol infusion also caused significant difference in GPX level at 2 hours compared to controls (23.79 + 14.68 U/gm Hb vs 38.3 +/- 8.95 U/gm Hb, p = 0.003).


CONCLUSIONS
Free radical levels are raised in patients with MI which may contribute to reperfusion injury. The antioxidant action of esmolol was clearly observed by significant difference in MDA level and GPX sparing effect. Large scale clinical trials may establish conclusively role of beta blockers as antioxidants as adjuvant to thrombolytic therapy in MI.
Daga
M K
MK
Maulana Azad Medical College and Associated Lok Nayak and GB Pant Hospitals, New Delhi 110 002.
Chaudhary
Madhuchanda
M
Sharma
Bhavneesh
B
Bhattacharjee
Jayshree
J
Ghambhir
D S
DS
Arora
N
N
Sudha
R
R
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000975:Antioxidants / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005609:Free Radicals / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy*; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D016877:Oxidants / Q000097:blood; D011412:Propanolamines / Q000627:therapeutic use*; D011446:Prospective Studies
D000319:Adrenergic beta-Antagonists; D000975:Antioxidants; D005609:Free Radicals; D016877:Oxidants; D011412:Propanolamines; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; C036604:esmolol