Table 4 Subgroup analysis

Risk factors

Age, mean(±SD)

61.1(14.1)

64.9(19.5)

0.20

59.4(14.9)

67.1(14.7)

0.01

Males, no. (%)

52(82.5)

11(73.3)

0.21

45(84.9)

18(72.0)

0.09

Diabetes, no. (%) [1]*

11(17.5)

2(14.3)

0.39

3(5.7)

10(41.7)

<0.01

Hypertension, no. (%) [1]

32(50.8)

7(50.0)

0.48

27(50.9)

12(50.0)

0.46

Hyperlipidaemia, no. (%) [11]

25(46.3)

3(23.1)

0.07

19(41.3)

9(42.9)

0.45

History of IHD, no. (%) [2]

17(27.4)

3(21.4)

0.33

15(28.8)

5(20.8)

0.23

Serum creatinine μmol/L, median(IQR)

102(86–115)

125(113–161)

<0.01

100(84–114)

119(107–142)

<0.01

GFR ml/min, median(IQR)

63(52–78)

46(37–54)

<0.01

66(55–81)

50(42–60)

<0.01

History of smoking, no. (%) [19]

41(80.4)

6(75.0)

0.37

34(79.1)

13(81.3)

0.42

Peri cardiac arrest factors

Time, min to first hospital, median(IQR) [16]

52(40–61)

70(51–80)

<0.01

50(40–60)

63(50–73)

0.02

Time, hrs to TPCH, median(IQR)

3.9(1.0 -9.3)

4.0(1.9–6.9)

0.14

5.75(1.05–11.8)

1.25(1–4)

<0.01

History of chest pain, no. (%) [3]

21(33.9)

4(30.8)

0.42

16(31.4)

9(37.5)

0.30

Time to ROSC in min, median(IQR) [11]

15(10–25)

22.5(15–29)

0.36

13.5(10–22.2)

20(15–35)

0.01

Treated at a peripheral hospital, no. (%)

35(55.6)

11(73.3)

0.12

35(66.0)

11(44.0)

0.03

ECG factors

Initial rhythm VF/VT, no. (%)

56(88.9)

9(60.0)

<0.01

47(88.7)

18(72.0)

0.03

ST elevation, no. (%)

30(47.6)

2(13.3)

<0.01

21(39.6)

11(44.0)

0.36

QTc in milliseconds, mean(±SD) [2]

453(46)

464(51)

0.23

454(48.4)

457(43.4)

0.42

Assessments and tests

GCS by paramedics, mean(±SD) [2]

5.4(4.7)

3.0(0)

0.03

5.84(5.06)

3.12(0.6)

<0.01

CCF in ED, no. (%)

9(14.3)

2(13.3)

0.46

5(9.4)

6(24.0)

0.04

First measured LVEF, mean(±SD) [6]

37.7(17.2)

36.7(21.6)

0.43

39.2(18.2)

33.5(16.8)

0.11

Initial serum K mmol/L, mean(±SD)

3.9(0.7)

4.2(0.6)

0.06

3.9(0.7)

4.0(0.7)

0.20

Initial serum Mg mmol/l, mean(±SD) [5]

1.0(0.3)

1.0(0.5)

0.49

1.0(0.3)

1.1(0.6)

0.06

Peak CK in IU/L, median(IQR) [9]

1440(524–3562)

1810(1070–4050)

0.15

1440(544–3442)

1810(613–3870)

0.37

Peak Troponin I in μmol/L, median(IQR) [5]

20(4–71)

9(1–35)

0.20

15(5–56)

32(1–75)

0.42

Treatments

Use of inotropes, no. (%)

27(42.9)

8(52.3)

0.24

20(37.7)

15(60.0)

0.03

Heparin/Enoxaparin, no. (%) [1]

59(93.7)

14(100)

0.34

51(96.2)

22(91.7)

0.21

Aspirin, no. (%) [1]

62(98.4)

11(78.6)

<0.01

52(98.1)

21(87.5)

0.03

Clopidogrel, no. (%) [1]

50(79.4)

3(21.4)

<0.01

37(69.8)

16(66.7)

0.39

Balloon pump, no. (%)

20(31.7)

2(13.3)

0.08

15(28.3)

7(28.0)

0.49

ICU stay in days, median(IQR)

4(2–6)

4(2–5.5)

0.36

4(2–6)

4(2–4)

0.15

Coronary angiogram at any time, no. (%)

N/A

N/A

N/A

47(88.7)

16(64.0)

<0.01

Initially presenting to TPCH

18 patients

14 patients

Emergent coronary angiogram, no. (%)

11(61.1)

11(78.6)

0.15

Coronary angiogram at any time, no. (%)

16(88.9)

12(85.7)

0.40

Outcomes

OOHCA caused by AMI, no. (%)

45(71.4)

6(40.0)

0.01

Survived to discharge, no. (%)

47(74.6)

6(40.0)

<0.01

Neurological deficit, no. (%)

7(11.1)

0(0.0)

0.09

Neurological deficit in survivors, no. (%)

7/47(14.9)

0/6(0.0)

0.16