Diagnostic Performance of Point-of-Care Troponin I and Laboratory Troponin T in Patients Presenting to the ED with Chest Pain: A Comparative Study

Figures & data

Table 1 Characteristics of Patients with Chest Pain

Variables		Number	Valid %
Age in years (mean)		44
gender
	Male	286	94.4
	Female	17	5.6
IHD Risk factors
	Hypertension	89	30.0
	Cigarette smoking	77	25.8
	Family History of IHD	69	23.3
	Diabetes Mellitus	67	22.6
	Hyperlipidemia	36	12.2
Duration of chest pain (hours) Mean		46.13 ± 103.4
Median		18
Range		0.5–288
ECG
	Normal	227	75.7
	Abnormal	72	24.3
Disposition
	ICU	43	14.0
	Discharge	258	86.0
Final Diagnosis
	STEMI	5	1.7
	NSTEMI	35	11.6
	Unstable angina	4	1.3
	Stable angina	7	2.3
	non-Cardiac	252	83.2
Return to ED within one month
	No	299	98.7
	Yes*	4	1.3

Notes: * From the patients discharged from ED, 4 returned back within one month: 1- NSTEMI -Admitted to ICU, 2-Non cardiac chest pain discharged from ED with normal Stress test,1 - intestinal obstruction- Admitted to surgery)

Table 2 Comparison of Risk Factors in Patients with Cardiac and Non-Cardiac Chest Pain

	Cardiac		Non-Cardiac
Risk Factors	no.	%	no.	%	P value*
HTN	20	40.8	69	27.8	0.07
DM	14	28	53	21.4	0.313
CAD	5	10.2	26	10.5	0.946
Dyslipidemia	6	12.2	30	12.1	0.985
Smoking	23	46	54	21.7	0.000
Family History of CAD	16	31.3	53	21.6	0.134

Figure 1 Flow chart showing patient enrollment.

Table 3 Diagnostic Performance of POC TNI and Lab HTNT Assays

	POC TNI First Test (Zero Hour)	POC TNI Second Test (After 3 Hours)	HTNT – First Test (Zero Hour)	HTNT – Second Test (After 3 hrs)
Sensitivity (95% CI)	72.5 (57.2–83.9)	95 (83.5–98.6)	97.5 (87.1–99.5)	100 (91.2–100)
Specificity (95% CI)	99.24 (97.3–99.8)	100 (98.6–100%)	93.2 (89.5–95.6)	94.3 (90.8–96.5)
PPV (95% CI)	93.5 (79.3–98.2)	100 (90.8–100)	68.4 (55.5–79)	72.7 (59.7–82.7)
NPV (95% CI)	95.96 (92.9–97.7)	99.2 (97.3–99.8)	99.6 (97.7–99.9)	100 (98.5–100)
Diagnostic accuracy (%)	95.7 (92.8–97.5)	99.3 (97.6–99.8)	93.7 (90.4–95.9	95 (91.9–96.9)
Likelihood ratio of a positive test	95.3 (34.8–260.6)	undefined	14.3 (12.8–15.9)	17.53 (15.4–19.9)
Likelihood ratio of a negative test	0.27(0.23–0.33)	0.05 (0.01–0.13)	0.02 (0.00–0.19)	0.0

Figure 2 The ROC Curves of the POC TNI and the Lab HTnT at 0 hour and 3 hours.