ASSESSMENT OF REPERFUSION OF THE INFARCT ZONE AFTER ACUTE MYOCARDIAL-INFARCTION BY SERIAL CARDIAC TROPONIN-T MEASUREMENTS IN SERUM

Background-The purpose of this study was to derive indices of reperfus ion and non-reperfusion after acute myocardial infarction (AMI) from c hanges in serum concentrations of cardiac troponin T and to test the p redictive value of these indices. Methods-The indices were derived fro m a retrospective analysis of changes in serum troponin T concentratio n in 71 patients given thrombolytic treatment who had immediate and la te angiography (group 1). These troponin T indices were first tested i n a blinded and prospective study of 53 consecutive patients eligible for thrombolytic therapy (group 2). They were then used for the non-in vasive assessment of reperfusion of AMI in 48 patients (group 3). Resu lts-In group 1 troponin T serum concentration curves were biphasic in patients who had reperfusion less than or equal to 5.8 h after the ons et of symptoms. Release of the cytosolic troponin T pool resulted in a peak at 14 h and ended at 38 h. The probability of reperfusion was >9 5% when the ratio of peak cytosolic troponin T concentration to concen tration at 38 h (PV1/38) exceeded 1.42 or the ratio of troponin T conc entration at 14 h to that at 38 hours (14/38) exceeded 1.09. The proba bility of the presence of non-reperfused AMI was <5% when troponin T P V1/38 and 14/38 ratios were <0.99 and <0.84 respectively. These discri minatory values of troponin T indices correctly classified (efficiency 96%) 48 of the 53 group 2 patients in whom immediate and late angiogr aphy were performed. When troponin T indices were used to classify 48 group 3 patients who were not studied by immediate angiography, thromb olytic therapy was deemed to have been successful in 82% of the treate d patients, with spontaneous recanalisation in 11% and 23% of the non- treated patients assessed by PV1/38 and 14/38 respectively. Conclusion -The PV1/38 or 14/38 ratios of serum troponin T concentration indicate d the effectiveness of thrombolytic therapy in achieving reperfusion o f AMI.