Serum amyloid A predicts early mortality in acute coronary syndromes: A TIMI 11A substudy

OBJECTIVES We evaluated the ability of serum amyloid A (SAA), alone and in combination with a rapid qualitative assay for cardiac-specific troponin T (cTnT), to predict 14-day mortality in patients with unstable angina or non -Q wave myocardial infarction (NQMI). BACKGROUND Elevated C-reactive protein (CRP) has been associated with adver se outcomes in unstable coronary syndromes but data regarding its acute pha se counterpart, SAA, are conflicting. METHODS Serum amyloid A measurement and a rapid cTnT assay were performed o n blood obtained at enrollment into Thrombolysis in Myocardial Infarction 1 1A, a dose-ranging trial of enoxaparin for unstable angina and NQMI. RESULTS Serum amyloid A was higher in patients who died compared with survi vors (6.28 vs. 0.75 mg/dL, p = 0.002). Among patients with a negative rapid cTnT, mortality was higher for those in the top quintile of SAA (6.1 vs. 0 .7%, p = 0.003). Patients with both an early positive rapid cTnT (less than or equal to 10 min until assay positive) and SAA in the fifth quintile had the highest mortality followed by those with either markedly elevated SAA or an early positive rapid cTnT, while patients with both a negative rapid cTnT and SAA in quintiles 1-4 were at very low risk, (9.1 vs. 3.6 vs. 0.7%, p < 0.002). CONCLUSIONS Similar to CRP, baseline elevation of SAA identifies patients h ospitalized with unstable angina and NQMI at higher risk for early mortalit y, even among those with a negative rapid assay for cTnT. These data suppor t further investigation of inflammatory markers used alone and in combinati on with cardiac troponins for risk assessment in unstable coronary syndrome s. (J Am Coll Cardiol 2000;35:358-62) (C) 2000 by the American College of C ardiology.