[Significance of the antioxidant factor, thioredoxin, in heart failure]

Increases in oxidative stress may be involved in the progression of heart diseases. However, the serum levels of thioredoxin, a redox regulating protein, have been poorly investigated in patients with heart diseases. This study evaluated the clinical significance of the serum thioredoxin levels in patients with heart failure.

The serum thioredoxin levels were determined with a sandwich enzyme-linked immunosorbent assay in a total of 34 patients with dilated cardiomyopathy (n = 5), acute coronary syndrome (n = 7), and stable angina (n = 18), including effort angina (n = 7) and vasospastic angina (n = 11), and control subjects (n = 4).

The serum thioredoxin levels were significantly elevated in patients with acute coronary syndrome (30.6 +/- 4.9 ng/ml, p < 0.001) and dilated cardiomyopathy (36.9 +/- 8.6 ng/ml, p < 0.001), but not in patients with stable angina (16.8 +/- 5.7 ng/ml, p = 0.27) compared with the control subjects (n = 4, 13.0 +/- 4.9 ng/ml). The serum thioredoxin level in patients with III and IV functional classes of the New York Heart Association (n = 8, 33.3 +/- 8.6 ng/ml, p < 0.001) was significantly higher than in the control subjects. In addition, the serum thioredoxin levels were negatively correlated with left ventricular ejection fractions of the patients (r = 0.59, p < 0.001).

These results indicate a possible association between thioredoxin and the severity of heart failure.