Relation between intermediate troponin T values and diagnosis of cardiac disease

Troponins are useful tools in management of patients with acute coronary syndrome (ACS). Small increases do not guarantee a desirable precision (CV < 10%) and there is a "grey zone" between 99 percentile and clinical cut off. Our objective was to evaluate if "grey zone" troponin values reflect heart damage or they are only "analyzer noise". Final diagnoses of patients with "grey zone" values attended during 2001 and 2002 were reviewed (group Tn). Control group (Cn): patients with negative values (four months randomly chosen during the same period). Admitted patients were classified in: A, ACS; B, non ischemic heart disease, and C, non heart disease. Tn group (n = 521): admitted, 330 (63.3%); A (53.9%), B (30.9%), C (15.2%). Cn group (n = 652): admitted, 156 (23.9%); A (41%), B (24.4%), C (34.6%). Odds ratio for admittance (Tn vs Cn) was 4.82 (95% CI, 3.68-6.31); OR for diagnosis A, B and C (Tn vs Cn) were: A (1.56) (95% CI, 1.04-2.34), B (1.43) (95% CI, 0.90-2.25), C (0.38) (95% CI, 0.24-0.6). Intermediate troponin values are associated with diagnosis of heart disease, especially ACS.