Beginning Monday, March 13, 2000 at 7:00 a.m., the Clinical Chemistry Laboratory of the Department of Pathology will institute a new testing platform for cardiac markers. The following markers will be offered CK-MB and Troponin T. The CK-MB test is equivalent to the previous test in terms of sensitivity and specificity except for a change in decision level. The new decision levels for CK-MB are greater than 7.5 ng/mL when the total CK is within the reference range and greater than 2.5 for an index when the total CK is outside the reference range.

Troponin T is equivalent to Troponin I in terms of sensitivity and specificity in detecting cardiac lesions (see ref.). A level of Troponin T greater than 0.1 ng/mL is considered significant.

Sample volumes and tube types remain the same. Pathology requisitions will be revised in the future to reflect this change. For now, an order for Troponin I received after March 13th will receive a Troponin T. Questions may be directed to Dr. Ronald Feld at 6–1759.

References:
1. Hamm CW, et al. Benefit of ABCIXIMAB in patients with refractory unstable angina in relation to serum Troponin T levels. N Engl J Med 1999;340:1623-9.

2. Christenson RH, et al. Cardiac troponin T and cardiac troponin I: relative values in short-term risk stratification of patients with acute coronary syndromes. Clin Chem 1998;44:494-501.

3. Lindahl B, et al. The FRISC experience with troponin T. Use as decision tool and comparison with other prognostic markers. Eur Heart J 1998;19:N51-N58.

4. Porter GA, et al. Troponin T, a predictor of death in chronic haemodialysis patients. Eur Heart J 1998;19:N34-N37

5. Wu AHB, et al. Biochemical differences between cTnT and cTnl and their significance for diagnosis of acute coronary syndromes. Eur Heart J 1998;19:N25-N29.

6. Hetland Ø, et al. Cardiac troponins I and T in patients with suspected acute coronary syndromes: a comparative study in a routine setting. Clin Chem 1998;44:1430-1436.

7. McErlean ES, et al. Comparison of troponin T versus creatine kinase-MB in suspected acute coronary syndromes. Am J Cardiol 2000;85:421-426.