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 10 h of onset and were successfully reperfused by primary percutaneous coronary intervention. Plasma SAA concentrations were evaluated at 24 h after onset. The threshold of the upper quintile (325 mug/dl) was used to divide patients into 2 groups: either a high SAA (H group: > or =325 mug/dl; n=56) or low SAA (L group: <325 microg/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.