Mechanisms behind the prognostic value of troponin T in unstable coronary artery disease: A FRISC II substudy

OBJECTIVES This study was designed to elucidate possible mechanisms for the prognostic value of troponin T (tnT). BACKGROUND The reasons for the adverse prognosis associated with elevation of troponins in unstable coronary artery disease are poorly understood. METHODS Patients enrolled in the Fast Revascularization during InStability in CAD (FRISC-II) trial were included. Clinical characteristics, findings a t echo cardiography and coronary angiography, and prognosis were evaluated in relation to different tnT levels. RESULTS Absence of significant coronary stenosis was more frequent and thre e-vessel disease or left main stem stenosis was less frequent in patients w ithout, compared with, detectable tnT. The occurrence of visible thrombus i ncreased with rising levels of tnT. In the group with the highest levels of tnT, occlusion of the left circumflex artery was more common than in the t hree other tnT groups, as was a left ventricular ejection fraction below 0. 45. The one-year risk of death in the noninvasive arm of the study increase d by increasing levels of tnT (1.6% to 4.6%), whereas the risk of myocardia l infarction showed an inverted U-shaped curve and was lower in the lowest (5.5%) and highest (8.4%) tnT groups than in the two intermediate groups (1 7.5% and 16.2%). CONCLUSIONS Any detectable elevation of tnT raises the,probability of signi ficant coronary stenosis and thrombus formation and is associated with an i ncreased risk of reinfarction and death. However, at a more pronounced elev ation of troponin, a higher proportion of patients has a persistent occlusi on of the culprit vessel and reduced left ventricular function, associated with a high mortality but a modest risk of reinfarction. (C) 2001 by the Am erican College of Cardiology.