Value of the high-sensitivity troponin T assay for diagnosis of acute myocardial infarction in patients with and without renal insufficiency

Figures & data

Figure 1. Enrollment flowchart and patient status. Low eGFR was defined as eGFR < 60 mL/min/1.73m² and normal eGFR was defined as eGFR ≥ 60 mL/min/1.73m². Abbreviations: CCU, cardiac care unit; eGFR, estimated glomerular filtration rate; AMI, acute myocardial infarction.

Table 1. Demographic and clinical characteristics of patients with moderate to severe renal insufficiency and normal kidney function.

Characteristic	All patients (n = 359) No. (%)^b	eGFR < 60 mL/min/1.73 m^2 (n = 240) No. (%)^b	eGFR ≥ 60 mL/min/1.73 m^2 (n = 119) No. (%)^b	p Value
Age, mean ± SD (yr)	69.5 ± 13.8	72.7 ± 12.8	63.1 ± 13.6	<0.001
Men	223 (62.1)	137 (57.1)	86 (72.3)	0.006
BMI, mean ± SD (kg/m^2)	24 ± 4.4	23.7 ± 4.5	24.6 ± 4.1	0.097
Smoking	136 (37.8)	79 (32.9)	57 (47.9)	0.01
Primary disease
Diabetes	167 (46.5)	125 (52.1)	42 (35.3)	0.003
Hypertension	241 (67.1)	178 (74.2)	63 (52.9)	<0.001
CAD	109 (30.4)	83 (34.6)	26 (21.8)	0.014
HF	97 (27)	82 (34.2)	15 (12.6)	<0.001
CVA	55 (15.4)	45 (18.8)	10 (8.5)	0.011
PAOD	10 (2.8)	10 (4.2)	0 (0)	0.025
Liver cirrhosis	9 (2.5)	7 (2.9)	2 (1.7)	0.723
Malignancy	31 (8.7)	21 (8.8)	10 (8.5)	0.931
COPD	32 (8.9)	25 (10.4)	7 (5.9)	0.156
Initial findings^c
BUN, median (IQR) (mEq/L)	31.3 (19.5–52.1)	37.6 (26.8–57.1)	16.5 (13.5–21.6)	<0.001^a
Cr, median (IQR) (mEq/L)	1.4 (1.0–2.3)	1.9 (1.4–3.6)	0.89 (0.8–1.0)	<0.001^a
eGFR, median (IQR) (mL/min/1.73 m^2)	53 (30.6–72.5)	35.2 (22.9–48.1)	76 (67.9–94)	<0.001^a
Na (mEq/L)	136.9 ± 9.1	136.4 ± 10.2	138 ± 6.1	0.103
K (mEq/L)	4.3 ± 1	4.5 ± 1	4 ± 0.6	<0.001
Cl (mEq/L)	99.3 ± 7.1	99.1 ± 7.4	100 ± 5.5	0.669
Ca (mg/dL)	8 ± 1	8.9 ± 1.1	8.8 ± 0.7	0.889
P (mg/dL)	4.8 ± 2.3	4.9 ± 2.4	4 ± 2.1	0.125
Mg, median (IQR) (mEq/L)	1.7 (1.6–1.9)	1.8 (1.6–2)	1.7 (1.6–1.8)	0.001^a
Hemoglobin (g/dL)	12.2 ± 2.9	11.4 ± 2.9	13.7 ± 2.3	<0.001
Albumin (g/dL)	3.6 ± 0.6	3.6 ± 0.5	3.8 ± 0.6	<0.001
Total cholesterol (mg/dL)	164.3 ± 50.8	151.7 ± 47.1	179.6 ± 51.2	<0.001
TG, median (IQR) (mg/dL)	113.5 (79–160)	98 (77.3–154.8)	125.5 (85.8–169)	0.054^a
LDL (mg/dL)	105.9 ± 47	93.8 ± 41.6	120.5 ± 49.1	<0.001
HDL (mg/dL)	43.3 ± 15.8	42.2 ± 15.8	44.6 ± 15.7	0.256
HbA1c (%)	6.9 ± 1.66	6.8 ± 1.6	6.9 ± 1.7	0.515
Troponin-T, median (IQR) (ng/L)	142.3 (53.4–385)	160.4 (74–415.3)	97.7 (28–366.2)	0.002^a
Relative changes in troponin-T at 3-hours, median (IQR) (%)	42.6 (2.7–361.2)	21.7 (1–142.5)	204.9 (38.5–2712)	<0.001^a

^ap Value using Mann-Whitney U test.

^bAll data are No. (%) unless otherwise indicated.

^cData are mean ± SD unless otherwise indicated.

eGFR: estimated glomerular filtration rate; BMI: body mass index; CAD: coronary artery disease; HF: heart failure; CVA: cerebral vascular accident; PAOD: peripheral arterial occlusive disease; COPD: chronic obstructive pulmonary disease; BUN: blood urea nitrogen; Cr: creatinine; TG: triglycerides; LDL: low-density lipoprotein; HDL: high-density lipoprotein; HbA1c: glycohemoglobin.

Table 2. Clinical presentation of patients having elevated high-sensativity troponin-T.

Presentation	Overall (n = 359) No. (%)	eGFR (mL/min/1.73 m^2)
		<60 (n = 240) No. (%)	≥60 (n = 119) No. (%)
Dyspnea	168 (46.8)	138 (57.5)	30 (25.2)
Orthopnea	115 (32)	97 (40.4)	18 (15.1)
Chest pain	192 (53.5)	104 (43.3)	88 (73.9)
Epigastric pain	16 (4.5)	12 (5)	4 (3.4)
Consciousness change	24 (6.7)	18 (7.5)	6 (5)
Cardiac arrest	32 (8.9)	24 (10)	8 (6.7)

Table 3. Final diagnoses of patients admitted to CCU and the corresponding levels of high-sensitivity troponin-T.

	Overall (%), n = 359	eGFR (mL/min/1.73 m^2)		p Value*
		< 60 (%), n = 240	≥ 60 (%), n = 119
AMI	236 (65.7)	138 (57.5)	98 (82.4)
Initial troponin-T, median (IQR) (ng/L)	144.4 (50.1–614.3)	180.2 (76.5–645.3)	100.7 (28.2–526.3)	0.002
Relative changes in troponin-T at 3-hours, median (IQR) (%)	132.1 (30.1–866)	77.9 (21.8–404.5)	256.5 (64.1–5722.5)	<0.001
Non-AMI	123 (34.3)	102 (42.5)	21 (17.6)
Heart failure	97 (27)	82 (34.2)	15 (12.6)
Initial troponin-T, median (IQR) (ng/L)	138.6 (50.2–250.3)	143.2 (56.7–260)	30.1 (17.9–214.5)	0.193
Relative change in troponin-T at 3-hours, median (IQR) (%)	2.7 (−3.5–10.9)	2.6 (−3.3–10.4)	12 (−12–410.4)	0.365
Stroke	5 (1.4)	2 (0.8)	3 (2.5)
Initial troponin-T, median (IQR) (ng/L)	94.6 (35.2–139.4)	71.7 (30.4 − 113)	94.6 (39.9–165.8)	0.564
Relative change of troponin-T at 3-hours, median (IQR) (%)	−13.3 (−15.3–1)	5939 (1 − 11876)	−15.3 (−17.6–−13.3)	0.121
Sepsis	21 (5.9)	18 (7.5)	3 (2.5)
Initial troponin-T, median (IQR) (ng/L)	260 (131.4––450)	256.2 (130–450.4)	409.9 (212.6–462.6)	0.421
Relative change in troponin-T at 3-hours, median (IQR) (%)	−0.4 (−9.7–24)	−0.5 (−8.2–3.8)	42.2 (−12–47.2)	0.314

*p Value: eGFR < 60 versus > 60 mL/min/1.73 m² applying the Mann-Whitney U test.

CCU: cardiac care unit; eGFR: estimated glomerular filtration rate; AMI: acute myocardial infarction.

Figure 2. Receiver operating characteristic curves of high-sensitivity cardiac troponin-T (TnT) levels on admission, and dynamic changes in these levels for the diagnosis of acute myocardial infarction (diagnosis based on coronary angiography or cardiac echocardiography) (A) for patients with eGFR < 60 mL/min/1.73 m², (B) patients with eGFR > 60 mL/min/1.73 m², (C) patients with chronic kidney disease (CKD) history, and (D) patients without CKD history.

Figure 3. Receiver operating characteristic curves of high-sensitivity cardiac troponin-T (TnT) levels on admission and dynamic changes in these levels for the diagnosis of acute myocardial infarction (diagnosis based on coronary angiography only) (A) for patients with eGFR < 60 mL/min/1.73 m², (B) patients with eGFR > 60 mL/min/1.73 m², (C) patients with chronic kidney disease (CKD) history, and (D) patients without CKD history.

Table 4. Diagnostic performance of dynamic change for high-sensitivity cardiac troponin-T levels for the diagnosis of acute myocardial infarction.

Performance	eGFR < 60 mL/min/1.73 m^2, n = 240 AUC (95% CI), 0.82 (0.76–0.88)
Relative change in hs-cTnT	Sensitivity	Specificity	PPV	NPV
5%	0.85	0.66	0.79	0.77
9%	0.82	0.74	0.81	0.75
16%	0.77	0.84	0.87	0.73
25%	0.73	0.85	0.87	0.7
	eGFR ≥ 60 mL/min/1.73 m^2, n = 119 AUC (95% CI), 0.82 (0.71–0.94)
3%	0.96	0.5	0.9	0.73
7%	0.94	0.56	0.91	0.67
12%	0.93	0.62	0.92	0.59
48%	0.8	0.75	0.94	0.44

eGFR: estimated glomerular filtration rate; AUC: area under the receiver operating characteristic curve; hs-cTnT: high-sensitivity cardiac troponin-T; PPV: positive predictive value; NPV: negative predictive value.

Table 5. Optimal cutoff values for dynamic changes in high-sensitivity cardiac troponin-T levels for the diagnosis of acute myocardial infarction.

	Diagnosis of AMI based on coronary angiography or echocardiography
Performance	eGFR < 60 mL/min/1.73 m^2 (n = 240)	eGFR ≥ 60 mL/min/1.73 m^2 (n = 119)	CKD history (n = 157)	No CKD history (n = 202)
Cutoff value	16%	12%	16%	11%
AUC (95% CI)	0.82 (0.76–0.88), p < 0.001	0.82 (0.71–0.94), p < 0.001	0.8 (0.72–0.87), p < 0.001	0.86 (0.79–0.93), p < 0.001
Sensitivity	0.77	0.93	0.83	0.9
Specificity	0.84	0.62	0.8	0.71
	Diagnosis of AMI based on coronary angiography only
	eGFR < 60 mL/min/1.73 m^2 (n = 119)	eGFR ≥ 60 mL/min/1.73 m^2 (n = 98)	CKD history (n = 73)	No CKD history (n = 144)
Cutoff value	16%	9%	16%	8%
AUC (95% CI)	0.78 (0.66–0.89), p < 0.001	0.78 (0.56–1), p = 0.022	0.76 (0.62–0.89), p = 0.002	0.76 (0.56–0.96), p = 0.022
Sensitivity	0.77	0.94	0.74	0.92
Specificity	0.82	0.67	0.88	0.57

eGFR: estimated glomerular filtration rate; CKD: chronic kidney disease; AUC: area under the receiver operating characteristic curve.

Table 6. Subgroup analyses of initial and relative change of high-sensitivity cardiac troponin-T for diagnosis performance of acute myocardial infarction.

		Initial hs-cTnT		Relative change in hs-cTnT (%)
	n	AUC (95% CI)	p Value	AUC (95% CI)	p Value	Optimal cutoff values	Sensitivity	Specificity
eGFR stages
Stage 1	35	0.36 (0.11–0.6)	0.246	0.96 (0.88–1)	<0.001	9.5%	1	0.75
Stage 2	84	0.51 (0.35–0.67)	0.952	0.78 (0.63–0.93)	<0.001	12%	0.9	0.59
Stage 3	103	0.59 (0.47–0.7)	0.139	0.86 (0.78–0.94)	<0.001	19.6%	0.81	0.81
Stage 4	44	0.65 (0.47–0.82)	0.102	0.83 (0.69–0.97)	<0.001	15.6%	0.85	0.8
Stage 5	93	0.57 (0.45–0.69)	0.276	0.78 (0.68–0.88)	<0.001	17.8%	0.69	0.88
Age ≥ 70 y/o
eGFR < 60 mL/min/1.73 m^2	150	0.65 (0.56–0.74)	0.048	0.81 (0.74–0.89)	<0.001	11%	0.83	0.78
eGFR ≥ 60 ml/min/1.73 m^2	40	0.65 (0.46–0.84)	0.186	0.7 (0.47–0.92)	0.076	N/A	N/A	N/A
Age < 70 y/o
eGFR < 60 mL/min/1.73 m^2	90	0.46 (0.33–0.58)	0.507	0.83 (0.74–0.92)	<0.001	17.8%	0.77	0.88
eGFR ≥ 60 ml/min/1.73 m^2	79	0.36 (0.19–0.54)	0.271	0.91 (0.82–1)	0.001	9.4%	0.97	0.67
CAD history
eGFR < 60 mL/min/1.73 m^2	83	0.45 (0.32–0.59)	0.507	0.8 (0.69–0.91)	<0.001	17.8%	0.81	0.84
eGFR ≥ 60 ml/min/1.73 m^2	26	0.78 (0.54–1)	0.089	0.76 (0.36–1)	0.205	N/A	N/A	N/A
No CAD history
eGFR < 60 mL/min/1.73 m^2	157	0.64 (0.55–0.73)	0.005	0.83 (0.76–0.9)	<0.001	16%	0.75	0.83
eGFR ≥ 60 ml/min/1.73 m^2	93	0.37 (0.23–0.51)	0.072	0.85 (0.74–0.96)	<0.001	9%	0.97	0.58
Heart failure history
eGFR < 60 mL/min/1.73 m^2	82	0.61 (0.48–0.74)	0.113	0.87 (0.79–0.96)	<0.001	11.2%	0.92	0.82
eGFR ≥ 60 ml/min/1.73 m^2	15	N/A*	N/A*	N/A*	N/A*	N/A*	N/A*	N/A*
No heart failure history
eGFR < 60 mL/min/1.73 m^2	158	0.56 (0.47–0.66)	0.218	0.8 (0.73–0.88)	<0.001	16%	0.72	0.83
eGFR ≥ 60 ml/min/1.73 m^2	104	0.46 (0.32–0.6)	0.597	0.83 (0.72–0.95)	<0.001	12%	0.94	0.63

Definition of eGFR stages: stage 1, eGFR ≥90 mL/min; stage 2, eGFR 60–89 mL/min; stage 3, eGFR 30–59 mL/min; stage 4, eGFR 15–29 mL/min; stage 5 eGFR <15 mL/min or under renal replacement therapy. Optimal cutoff value was defined as highest value of combination of sensitivity and specificity.*All patients diagnosed with acute myocardial infarction.

AUC: area under the receiver operating characteristic curve; CAD: coronary artery disease; eGFR: estimated glomerular filtration rate; hs-cTnT: high-sensitivity cardiac troponin-T; PPV: positive predictive value; NPV: negative predictive value; N/A: Not applicable; y/o: years old.