DIAGNOSTIC PERFORMANCE OF INITIAL SALIVARY ALPHA-AMYLASE ACTIVITY FOR ACUTE MYOCARDIAL INFARCTION IN PATIENTS WITH ACUTE CHEST PAIN

Background: To rule out acute myocardial infarction(AMI) inchest pain patients constitutes a diagnostic challenge to emergency department (ED) physicians. Study Objectives: To evaluate the diagnostic value of measuring salivary alpha-amylase (sAA) activity for detecting AMI in patients presenting to the ED with acute chest pain. Methods: sAA activity was measured in a prospective cohort of 473 consecutive adult patients within 4 h of onset of chest pain. Comparisons were made between patients with a final diagnosis of AMI and those with non-AMI. Univariate analysis and multiple logistic regression model were used to identify independent clinical predictors of AMI. Results: Initial sAA activity in the AMI group (n = 85; 266 +/- 127.6 U/mL) was significantly higher than in the non-AMI group (n = 388; 130 +/- 92.8 U/mL, p < 0.001). sAA activity levels were also significantly higher in patients with ST elevation AMI (n = 53) compared to in those with non-ST elevation AMI (n = 32) (300 +/- 141.1 vs. 210 +/- 74.1 U/mL, p < 0.001). The area under the receiver operating characteristic curve of sAA activity for predicting AMI in patients with acute chest pain was 0.826 (95% confidence interval [CI] 0.782-0.869), with diagnostic odds ratio 10.87 (95% CI 6.16-19.18). With a best cutoff value of 197.7 U/mL, the sAA activity revealed moderate sensitivity and specificity as an independent predictor of AMI (78.8% and 74.5%). Conclusions: High initial sAA activity is an independent predictor of AMI in patients presenting to the ED with chest pain. (C) 2012 Elsevier Inc.