Biochemical markers of cardiac damage: from efficiency to effectiveness

Testing for the diagnosis of acute myocardial infarction and other diseases included in the spectrum of the so-called "acute coronary syndrome" is rap idly changing from the traditional enzymatic assays to mass measurement of more specific and sensitive markers (cardiac troponins, CK-MB and myoglobin ). Several questions have arisen since the introduction of these new marker s into the clinical setting: the choice of strategies for optimizing the ut ilization of biochemical assays combining different (early and specific) ma rkers, the rationale for sampling specimens and the identification of clini cally useful turnaround times. The impressive clinical specificity and sens itivity assured by the measurement of cardiac troponins should be used for improving the effectiveness of patients' diagnosis and treatment. Troponins could be the paradigm of how a new diagnostic test and a therapeutic advan ce can be combined to the benefit of patients with acute coronary syndromes . In fact, in acute myocardial infarction (AMI) patients as well as in pati ents suffering from stable and unstable angina, the measurement of troponin s alone, or combined to that of other biochemical markers, should be of pra ctical value for the diagnosis, for the prognosis and for selecting the mos t effective therapeutic treatment. Limitations in cardiac markers should be classified into two groups: temporary and intrinsic limitations. Temporary limitations are: (a) current assays are not specific as to the analyte, (b ) the limited standardization precludes a comparison between results obtain ed with different techniques. Intrinsic limitations are the elevation of tr oponins in the so-called "minor myocardial damage", which often cannot be c onfirmed by other techniques, the evidence that other heart diseases, such as congestive heart failure and myocarditis, can lead to an increase in tro ponin concentrations, and finally that troponin is not an early marker. A s ound cooperation between cardiologists, physicians and laboratory specialis ts in explaining and understanding the advantages and limitations of curren t biochemical markers should allow us to move from efficiency to clinical e ffectiveness. (C) 2001 Elsevier Science BN. All rights reserved.