Prognostic Value of Serum Amyloid A Protein in Patients With Acute Myocardial Infarction

Background The relationship between plasma levels of serum amyloid A protein (SAA) concentrations and clinical course (including mortality) was investigated in patients with acute myocardial infarction (AMI). Methods and Results The study enrolled 280 consecutive AMI patients who were admitted within 10h of onset and were successfully reperfused by primary percutaneous coronary intervention. Plasma SAA concentrations were evaluated at 24h after onset. The threshold of the upper quintile (325μg/dl) was used to divide patients into 2 groups : either a high SAA (H group : ≥325μg/dl; n=56) or low SAA (L group : <325μg/dl; n=224). (I) Left ventricular (LV) ejection fraction in the chronic phase was significantly less in the H group than in the L group (52±14% vs 57±13%, p=0.03). (II) There were significantly more major complications in the H group than in the L group (cardiac rupture : p=0.0007, cardiogenic shock : p<0.0001; subacute thrombosis : p=0.0007; cardiac death : p=0.0003). (III) Multivariate analysis identified SAA as an independent predictor of 6-month mortality in AMI patients (risk ratio : 5.8, 95%confidence interval : 1.3-27.7, p=0.03). Conclusions In the setting of AMI, plasma SAA concentrations may be closely related to LV systolic dysfunction and poor patient outcomes, including mortality.