Association of Cardiac Troponin T Concentration on Admission with Prognosis in Critically Ill Patients without Myocardial Infarction: A Cohort Study

Figures & data

Figure 1 Selection of the study population.

Abbreviation: ICU, intensive care unit.

Table 1 Baseline Characteristics of the Study Population

Variable	Overall (N=2960)	Cardiac Troponin T Concentration on ICU Admission*		P
		Normal (≤0.01 ng/mL) (N=230)	Abnormal (>0.01 ng/mL) (N=2730)
Age (years)	71 (59–82)	74 (59.25–82)	71 (59–82)	0.352
Sex				0.169
Male	1685 (56.93%)	121 (52.61%)	1564 (57.29%)
Female	1275 (43.07%)	109 (47.39%)	1166 (42.71%)
Ethnicity				0.844
White	1941 (65.57%)	153 (66.52%)	1788 (65.49%)
Black/African American	232 (7.84%)	19 (8.26%)	213 (7.80%)
Hispanic/Latino	66 (2.23%)	5 (2.17%)	61 (2.23%)
Asian	72 (2.43%)	3 (1.30%)	69 (2.53%)
Other/Unknown	649 (21.93%)	50 (21.74%)	599 (21.94%)
Types of ICU**				<0.001
Coronary Care Unit	641 (21.66%)	21 (9.13%)	620 (22.71%)
Medical Intensive Care Unit	771 (26.05%)	67 (29.13%)	704 (25.79%)
Medical/Surgical Intensive Care Unit	478 (16.15%)	42 (18.26%)	436 (15.97%)
Cardiac Vascular Intensive Care Unit	247 (8.34%)	14 (6.09%)	233 (8.53%)
Surgical Intensive Care Unit	414 (13.99%)	42 (18.26%)	372 (13.63%)
Trauma Surgical Intensive Care Unit	310 (10.47%)	33 (14.35%)	277 (10.15%)
Neuro Surgical Intensive Care Unit	59 (1.99%)	6 (2.61%)	53 (1.94%)
Neuro Intermediate	27 (0.91%)	3 (1.30%)	24 (0.88%)
Neuro Stepdown	12 (0.41%)	2 (0.87%)	10 (0.37%)
Post-anesthesia Care Unit	1 (0.03%)	0 (0.00%)	1 (0.04%)
SAPS II on ICU admission	38 (30–48)	36 (29.25–44)	38 (30–48)	0.026
GCS on ICU admission	14 (10–15)	14 (11–15)	14 (10–15)	0.041
SOFA on ICU admission	5 (3–9)	4 (2–6)	5 (3–9)	<0.001
Charlson Comorbidity Index***	5 (4–7)	5 (4–7)	5 (3–7)	0.552
Dialysis on ICU admission	175 (5.91%)	3 (1.30%)	172 (6.30%)	0.002
Cardiac Troponin T concentration on ICU admission (ng/mL)*	0.07 (0.03–0.23)	0.01 (0.01–0.01)	0.08 (0.04–0.26)	-
≤0.01	230 (7.77%)	230 (100.00%)	-
0.02–0.04	843 (28.48%)	-	843 (30.88%)
0.05–0.08	526 (17.77%)	-	526 (19.27%)
0.09–0.26	686 (23.18%)	-	686 (25.13%)
≥0.27	675 (22.80%)	-	675 (24.73%)
Comorbidity***
Congestive heart failure	904 (30.54%)	52 (22.61%)	852 (31.21%)	0.007
Peripheral vascular disease	245 (8.28%)	22 (9.57%)	223 (8.17%)	0.460
Cerebrovascular disease	473 (15.98%)	46 (20.00%)	427 (15.64%)	0.083
Dementia	114 (3.85%)	12 (5.22%)	102 (3.74%)	0.262
Chronic pulmonary disease	649 (21.93%)	47 (20.43%)	602 (22.05%)	0.569
Rheumatic disease	88 (2.97%)	7 (3.04%)	81 (2.97%)	0.948
Peptic ulcer disease	61 (2.06%)	9 (3.91%)	52 (1.90%)	0.040
Mild liver disease	277 (9.36%)	20 (8.70%)	257 (9.41%)	0.719
Diabetes without complication	598 (20.20%)	55 (23.91%)	543 (19.89%)	0.144
Diabetes with complication	225 (7.60%)	17 (7.39%)	208 (7.62%)	0.900
Paraplegia	173 (5.84%)	14 (6.09%)	159 (5.82%)	0.870
Renal disease	594 (20.07%)	33 (14.35%)	561 (20.55%)	0.024
Malignant cancer	256 (8.65%)	25 (10.87%)	231 (8.46%)	0.212
Severe liver disease	86 (2.91%)	7 (3.04%)	79 (2.89%)	0.897
Metastatic solid tumor	108 (3.65%)	5 (2.17%)	103 (3.77%)	0.214
Acquired immunodeficiency syndrome	4 (0.14%)	1 (0.43%)	3 (0.11%)	0.277

Notes: *The maximum cardiac Troponin T concentration of available measurement records of cardiac Troponin T concentration examined within 24 hours before and after the date of first ICU admission; **The first ICU admission if a patient had more than 1 ICU admission during the hospitalization; ***Calculated or screened based on all diagnosis records made during the hospitalization.

Abbreviations: ICU, intensive care unit; SAPS II, Simplified Acute Physiology Score II; GCS, Glasgow Coma Scale; SOFA, Sequential Organ Failure Assessment.

Table 2 Prognosis of the Study Population According to Concentration of Cardiac Troponin T on ICU Admission

Concentration of Cardiac Troponin T on ICU Admission*	Cardiac Troponin T Concentration (ng/mL)*	Hospital Mortality	Length of Hospital Stay (Days)	Length of ICU Stay (Days)**
Two categories (ng/mL)
≤0.01 (normal)	0.01 (0.01–0.01)	17 (7.39%)	7.91 (4.92–12.91)	2.92 (1.74–5.13)
>0.01 (abnormal)	0.08 (0.04–0.26)	306 (11.21%)	8.69 (5.25–14.98)	3.27 (1.93–6.93)
P	–	0.075	0.160	0.002
Five categories (ng/mL)
≤0.01	0.01 (0.01–0.01)	17 (7.39%)	7.91 (4.92–12.91)	2.92 (1.74–5.13)
0.02–0.04	0.03 (0.02–0.04)	91 (10.79%)	8.05 (4.99–14.80)	2.99 (1.86–6.16)
0.05–0.08	0.06 (0.05–0.07)	69 (13.12%)	9.54 (5.75–15.08)	3.65 (2.00–7.25)
0.09–0.26	0.14 (0.11–0.19)	78 (11.37%)	8.56 (5.32–14.69)	3.10 (1.88–6.68)
≥0.27	0.62 (0.38–1.33)	68 (10.07%)	8.91 (5.24–15.42)	3.67 (2.08–8.00)
P	–	0.184	0.136	<0.001

Notes: *The maximum cardiac Troponin T concentration of available measurement records of cardiac Troponin T concentration examined within 24 hours before and after the date of first ICU admission; **The first ICU admission if a patient had more than 1 ICU admission during the hospitalization.

Abbreviation: ICU, intensive care unit.

Table 3 Association Between Concentration of Cardiac Troponin T on ICU Admission and Hospital Mortality

Concentration of Cardiac Troponin T on ICU Admission*	Crude			Model 1**			Model 2***
	Odds Ratio	95% CI	P	Odds Ratio	95% CI	P	Odds Ratio	95% CI	P
Two categories (ng/mL)
≤0.01 (normal)	1 (Reference)			1 (Reference)			1 (Reference)
>0.01 (abnormal)	1.58	0.95–2.63	0.077	1.39	0.81–2.37	0.228	1.50	0.88–2.57	0.140
Five categories (ng/mL)
≤0.01	1 (Reference)			1 (Reference)			1 (Reference)
0.02–0.04	1.52	0.88–2.60	0.131	1.39	0.78–2.44	0.261	1.44	0.81–2.56	0.209
0.05–0.08	1.89	1.09–3.30	0.024	1.67	0.93–3.00	0.086	1.71	0.95–3.09	0.074
0.09–0.26	1.61	0.93–2.78	0.089	1.27	0.71–2.25	0.423	1.36	0.76–2.43	0.302
≥0.27	1.40	0.81–2.44	0.230	1.31	0.73–2.36	0.360	1.58	0.87–2.87	0.133

Notes: *The maximum cardiac Troponin T concentration of available measurement records of cardiac Troponin T examined within 24 hours before and after the date of first ICU admission; **Model 1 was adjusting for age, sex, ethnicity, Simplified Acute Physiology Score II on ICU admission, and Charlson Comorbidity Index; ***Model 2 was adjusting for Model 1 and types of ICU. The type of ICU was determined by the first ICU admission if a patient had more than 1 ICU admission during the hospitalization.

Abbreviations: ICU, intensive care unit; CI, confidence interval.

Figure 2 Relationship between cardiac Troponin T concentration on ICU admission and probability of hospital mortality.

Notes: (A) presents the relationship between cardiac Troponin T concentration and hospital mortality based on a univariable logistic regression model. (B) is the same as the (A), but only cardiac Troponin T concentration within the range of 0.00–0.26 ng/mL is presented.

Abbreviation: ICU, intensive care unit.

Figure 3 Receiver operating characteristic curve for cardiac Troponin T concentration ICU on admission to predict hospital mortality.

Abbreviations: ICU, intensive care unit; AUC, area under the receiver operating characteristic curve; CI, confidence interval.