Abstract 2250: The Clinical Predictor of Activated Protein C in Patients with Acute Coronary Syndromes
Background Circulating markers indicating the instability of atherosclerotic plaques could have diagnostic and prognostic value in acute coronary syndromes. We evaluated activated protein C (APC), an antithrombotic, antiinflammatory, and profibrinolytic properties, as a clinical predictor of acute coronary syndromes.
Methods We conducted a prospective study of 459 patients with acute coronary syndromes (ACS). We measured APC in plasma specimens on arrival at the emergency room after onset of ACS, and subsequently performed emergency percutaneous coronary intervention if needed. In the cases of cardiogenic shock not quickly reversed with pharmacological therapy or restoration of spontaneous circulation (ROSC) with hemodynamic instability after out-of-hospital cardiac arrest, intra-aortic balloon pumping and or emergency cardiopulmonary bypass were performed immediately. Primary end point was death from any causes in hospital.
Results A total of 55 of the 459 patients died in hospital, and the APC level was lower among such patients than among those who discharged alive (mean±SD; 58.6±25.6% vs 87.8±30.2; p < 0.0001). The APC levels ranged from 10% and 205%, with a median of 82%. The unadjusted rate of death decreased in a stepwise fashion among patients in increasing quartiles of APC levels (with quartile 1 at 28.7% vs quartile 2 at 11.8% vs quartile 3 at 4.4% vs quartile 4 at 2.7%, p < 0.0001). The area under the receiver-operating-characteristics curve when APC was used to differentiate death from survival was 0.78 (95%CI; 0.71– 0.84), and the APC cutoff value of 56% had the highest combined sensitivity and specificity. In a multivariate logistic regression analysis for the independent predictors of death, including age, gender, Killip classification, heart rate, ECG findings, and APC valve of 56% or lower, APC valve of 56% or lower was the independent predictor of death with an adjusted odds ratio of 3.6 (95%CI; 1.6 –7.7).
Conclusions The measurement of APC provides predictive information for use in risk stratification across the spectrum of ACS. The intravenous infusion of recombinant human APC may be reduced mortality in patient with ACS, because APC activation was associated with an increased risk of death.