ABSTRACT
Objective To evaluate the diagnostic performance of plasma miR-499 in acute myocardial infarction (AMI) diagnosis.Methods Diagnostic accuracy test.The suspected AMI patients,who with chest pain for more than half an hour and been admitted in the Second People's Hospital of Wuxi and First People's Hospital of chuzhou during October 2010 and July 2011,were consecutively and prospectively enrolled in the present study.Sixty apparently healthy individuals were designed as healthy control.The plasma samples of the suspected AMI patients were collected within two hours after admission.The plasma miR-499 was determined by real time polymerase chain reaction (RT-PCR).The diagnostic performance of plasma miR-499 for AMI was estimated by receiver operating characteristic (ROC) curve analysis.The association between plasma miR-499 and AMI was analyzed by multivariable logistic model.The plasma miR-499 was determined and explained in blind fashion.Results Two hundred and nine suspected AMI patients,including 131 confirmed AMI patients (46 STEMI and 85 NSTEMI) and 78 AMI free patients were enrolled in the present study.The delta cycle threshold (ΔCT) was 1.01 ± 3.34 for AMI patients,-2.76 ± 2.90 for non-AMI patients and-3.79 ± 2.21 for healthy controls.The differences had statistical significance (x2 =96.77,P ＜ 0.01).The area under curve (AUC) of plasma miR-499 was 0.80 (95％ C I:0.74-0.86),lower than that of cardiac troponin Ⅰ (AUC =0.90,95％ CI:0.86-0.94) on admission (P ＜0.01).At the optimal cut-off of 0.18,the diagnostic sensitivity and specificity were 0.69 (95％ CI:0.61-0.77) and 0.77 (95％ CI:0.66-0.86),respectively.The coefficient of correlation between plasma miR-499 and cTnI was 0.72 (P ＜0.01).The odds ratio (OR) of plasma miR-499 ＞0.18 for AMI was 2.59 (95％ CI:1.10-6.07),after adjusted cTnI.Conclusions Plasma miR-499 is a useful biomarker for AMI diagnosis.It can provide additional diagnostic information beyond cTnI.Combination utility of plasma miR-499 and cTnI may improve the diagnostic accuracy for AMI.