Abstract 2613: Elevations in Serum Isoprostanes and Choline Correlate to 30 Day Outcomes in Patients with Acute Coronary Syndrome
Objectives: To evaluate the prognostic value of several biomarkers in patients with acute coronary syndrome (ACS) through evaluation of 30 day clinical outcomes. Background: Multiple biomarkers have emerged as potentially useful in risk stratification of ACS. Prior work has suggested the importance of serum troponin, C-reactive protein and choline levels on cardiovascular outcomes. The prognostic value of serum free F2-isoprostanes, a sensitive indicator of oxidative stress, has never been evaluated in ACS. Nonetheless, there is recent evidence that free F2-isoprostane dose correlate to coronary artery calcification.
Methods: We evaluated patients presenting with ACS defined by symptoms suggestive of cardiac ischemia plus:
ECG changes (ST depression or transient elevation of at least 1 mm or T wave changes in at least 2 leads), or
positive troponin. Levels of serum troponin I and T, hsCRP, IL-6, choline and free F2-isoprostane were obtained.
Patients were treated according to current standard of care for patients with ACS. Patients were followed for 30 days (N=108) with determination of cardiovascular events defined as cardiac death, congestive heart failure and/or ventricular arrhythmias.
Results: There were 26 patients with a cardiac event. While isoprostane and choline predicted 30 day cardiac events, neither hsCRP nor IL-6 were predictive. To determine the value of choline and isoprostane levels in predicting 30 day cardiac events, receiver operator curves were performed. Using these curves, the optimal cut-off point of these markers was a serum isoprostane level of 124.5 pg/ml (r=0.82) and a serum choline level of 30.5 μmol/L (r=0.76). Thus, serum isoprostane levels > 124.5 pg/ml were 74% sensitive and 81% specific in predicting cardiac events in patients with ACS and serum choline levels > 30.5 μmol/L were 73% sensitive and 71% specific. Isoprostane and choline had a positive predictive value of 57% and 44%, respectively, and a negative predictive value of 90% and 89%, respectively.
Conclusions: Serum choline and isoprostane levels are predictors of cardiac events in ACS. A model that includes a battery of biomarkers including troponin, choline, and isoprostane may be useful in predicting patients at higher risk of future events in ACS.