Serum cardiac marker	Test first becomes positive (hours)	Peak level (hours)	Sensitivity (%)	Specificity (%)	Positive predictive value (%) †	Negative predictive value (%) †
CK
Single assay	3 to 8	12 to 24	35	80	20	90
Serial assays			95	68	30	99
CK-MB
Single assay	4 to 6	12 to 24	35	85	25	90
Serial assays			95	95	73	99
Troponin I and T
Measured 4 hours after onset of chest pain	4 to 10		35	96	56	91
Measured 10 hours after onset of chest pain		8 to 28	89	95	72	98