CARDIAC-SPECIFIC TROPONIN-I LEVELS TO PREDICT THE RISK OF MORTALITY IN PATIENTS WITH ACUTE CORONARY SYNDROMES

Background In patients with acute coronary syndromes, it is desirable to identify a sensitive serum marker that is closely related to the de gree of myocardial damage, provides prognostic information, and can be measured rapidly. We studied the prognostic value of cardiac troponin I levels in patients with unstable angina or non-Q-wave myocardial in farction. Methods In a multicenter study, blood specimens from 1404 sy mptomatic patients were analyzed for cardiac troponin I, a serum marke r not detected in the blood of healthy persons. The relation between m ortality at 42 days and the level of cardiac troponin in the specimen obtained on enrollment was determined both before and after adjustment for base-line characteristics. Results The mortality rate at 42 days was significantly higher in the 573 patients with cardiac troponin I l evels of at least 0.4 ng per milliliter (21 deaths, or 3.7 percent) th an in the 831 patients with cardiac troponin I levels below 0.4 ng per milliliter (8 deaths, or 1.0 percent; P<0.001). There were statistica lly significant increases in mortality with increasing levels of cardi ac troponin I (P<0.001). Each increase of 1 ng per milliliter in the c ardiac troponin I level was associated with a significant increase (P= 0.03) in the risk ratio for death after adjustment for the base-line c haracteristics that were independently predictive of mortality (ST-seg ment depression and age greater than or equal to 65 years). Conclusion s In patients with acute coronary syndromes, cardiac troponin I levels provide useful prognostic information and permit the early identifica tion of patients with an increased risk of death. (C) 1996, Massachuse tts Medical Society.