Cardiac troponin I in aortic valve disease.

BACKGROUND

Plasma cardiac troponin I levels may be higher than normal in conditions other than ischemic heart disease. We aimed at measuring troponin I levels in aortic valve patients, in which increased values for left ventricular dimensions and pressure are frequently found.

METHODS

Plasma levels of troponin I, creatine kinase (CK) and the MB fraction of the same enzyme were measured in a group of 25 clinically stable aortic valve patients. Echocardiographic study was performed in all patients; hemodynamic and coronary angiographic study was performed in 19 patients. Troponin I was also measured in a control population (n=305).

RESULTS

The mean value for troponin I was found to be higher in aortic valve patients (0.07+/-0.02 ng/ml), when compared to controls (0.01+/-0.02 ng/ml; P<0.05). Significant correlations were found between troponin I and both creatine kinase and its MB fraction. When the 25 patients were divided into two groups, with lower (up to 0.04 ng/ml; 12 patients) and higher (0.05 ng/ml or greater; 13 patients) values for troponin I, patients with higher values were found to have greater mean left ventricular wall thickness (9.9+/-0.3 mm, n=11, vs. 12.1+/-0.3 mm, n=13) and pulmonary artery systolic pressures (36.6+/-2.5 mmHg, n=7, vs. 53.7+/-3.4 mmHg, n=9).

CONCLUSIONS

We conclude that slightly raised plasma levels of cardiac troponin I are relatively common in aortic valve patients with no evidence of ischemia. Higher left ventricular wall thickness and pulmonary artery systolic pressure may be related to slightly raised troponin I plasma levels.