Introduction
Materials and methods
Study patients
Hypothermia protocol
Data collection
Statistical analysis
Results
Patient characteristics
Hypothermia group (n= 110) | Normothermia group (n= 290) | P value | |
---|---|---|---|
Age (years) | 55 (46 to 68) | 74 (62 to 83) | <0.001 |
Male gender | 90 (82) | 177 (61) | <0.001 |
Pittsburgh overall performance category scale before index cardiac arrest | <0.001 | ||
Category 1 | 109 (99) | 216 (74) | |
Category 2 | 1 (1) | 62 (21) | |
Category 3 | 0 (0) | 12 (4) | |
Category 4 | 0 (0) | 0 (0) | |
Initial rhythm | <0.001 | ||
Ventricular fibrillation | 64 (58) | 41 (14) | |
Pulseless electrical activity | 23 (21) | 134 (46) | |
Asystole | 23 (21) | 115 (40) | |
Bystander cardiopulmonary resuscitation | 61 (55) | 137 (47) | 0.14 |
Time interval from collapse to start of cardiopulmonary resuscitation (minutes) | 6 (1 to 10) | 7 (1 to 14) | 0.049 |
Time interval from collapse to return of spontaneous circulation (minutes) | 35 (21 to 48) | 43 (23 to 56) | <0.01 |
Admission after 2006 | 83 (75) | 169 (58) | <0.01 |
Hypertension | 44 (40) | 85 (29) | 0.04 |
Diabetes mellitus | 29 (26) | 47 (16) | 0.02 |
Previous history of heart disease | 42 (38) | 63 (22) | <0.001 |
Previous history of myocardial infarction | 18 (16) | 15 (5) | <0.001 |
Previous history of chronic heart failure | 16 (15) | 27 (9) | 0.13 |
Cause of cardiac arrest | |||
Acute coronary syndrome | 46 (41) | 56 (19) | |
Old myocardial infarction | 12 (11) | 4 (1) | |
Cardiomyopathy | 13 (12) | 8 (3) | |
Spasm of coronary artery | 8 (7) | 2 (1) | |
Others | 27 (25) | 72 (25) | |
Unknown | 4 (4) | 148 (51) |
Hypothermia group (n= 110) | Normothermia group (n= 290) | P value | |
---|---|---|---|
Dose of epinephrine (mg) | 1 (0 to 3) | 1 (0 to 2) | 0.54 |
Emergency coronary angiography | 68 (62) | 34 (12) | <0.001 |
Primary percutaneous coronary intervention | 33 (30) | 16 (6) | <0.001 |
Use of intra-aortic balloon pump | 65 (59) | 22 (8) | <0.001 |
Use of extracorporeal life-support | 27 (25) | 13 (4) | <0.001 |
Time interval from return of spontaneous circulation to target temperature (minutes) | 149 (104 to 262) | ||
Protocol of duration of cooling/rewarming 24 hours/12 hours | 40 (36) | ||
Duration of cooling (hours) | 47 (24 to 49) | ||
Duration of rewarming (hours) | 47 (17 to 57) | ||
Duration of hospital stay (days) | 17 (5 to 29) | 1 (1 to 3) | <0.001 |
Cause of death within 30 days | |||
Hemodynamic instability | 21 (36) | 90 (37) | |
Withdrawal of intensive therapy | 18 (32) | 85 (35) | |
Multiple organ failure | 15 (26) | 10 (4) | |
Pneumonia | 3 (6) | 12 (5) | |
Other | 0 (0) | 46 (19) |
Outcomes
Hypothermia group (n= 110) | Normothermia group (n= 290) | |
---|---|---|
Favorable neurological outcome | 43 (39) | 40 (14) |
Good cerebral performance | 42 (38) | 39 (13) |
Moderate cerebral disability | 1 (1) | 1 (1) |
Severe cerebral disability | 0 (0) | 1 (1) |
Coma or vegetative state | 8 (7) | 8 (3) |
Dead | 59 (54) | 241 (82) |
Thirty-day survival | 53 (48) | 47 (16) |
CPA-ROSC | Sensitivity | Specificity | Positive predictive value | Negative predictive value | Accuracy (%) |
---|---|---|---|---|---|
Hypothermia group | |||||
18 minutes | 37 (28 to 46) | 91 (86 to 96) | 73 (65 to 81) | 69 (60 to 78) | 70 |
25 minutes | 60 (51 to 69) | 84 (77 to 91) | 70 (61 to 79) | 77 (69 to 85) | 74 |
29 minutes | 70 (61 to 79) | 79 (71 to 87) | 68 (59 to 77) | 80 (73 to 87) | 75 |
34 minutes | 79 (71 to 87) | 70 (61 to 79) | 63 (54 to 72) | 84 (77 to 91) | 74 |
45 minutes | 93 (88 to 98) | 40 (31 to 49) | 50 (41 to 59) | 90 (84 to 96) | 61 |
65 minutes | 100 | 4 (1 to 8) | 40 (31 to 49) | 100 | 42 |
Normothermia group | |||||
13 minutes | 73 (68 to 78) | 95 (92 to 98) | 71 (66 to 76) | 96 (94 to 98) | 92 |
15 minutes | 85 (81 to 89) | 94 (91 to 97) | 69 (64 to 74) | 98 (96 to 99) | 93 |
18 minutes | 90 (87 to 93) | 91 (88 to 94) | 62 (56 to 68) | 98 (96 to 99) | 91 |
20 minutes | 92 (89 to 95) | 88 (84 to 92) | 55 (49 to 61) | 99 (98 to 99) | 89 |
45 minutes | 100 | 49 (43 to 55) | 24 (19 to 29) | 100 | 56 |
Propensity matched analysis
Hypothermia-M group (n= 79) | Normothermia-M group (n= 79) | P value | |
---|---|---|---|
Age (years) | 60 (49 to 72) | 61 (50 to 71) | 0.62 |
Male gender | 62 (78) | 55 (70) | 0.20 |
Pittsburgh overall performance category scale 1 before index cardiac arrest | 78 (99) | 79 (100) | >0.99 |
Initial rhythm | 0.72 | ||
Ventricular fibrillation | 23 (29) | 25 (32) | |
Pulseless electrical activity | 35 (44) | 30 (38) | |
Asystole | 21 (27) | 24 (30) | |
Bystander cardiopulmonary resuscitation | 42 (53) | 37 (47) | 0.43 |
Time interval from collapse to start of cardiopulmonary resuscitation (minutes) | 8 (1 to 12) | 5 (1 to 10) | 0.29 |
Time interval from collapse to return of spontaneous circulation (minutes) | 35 (22 to 49) | 39 (14 to 50) | 0.86 |
Hypertension | 36 (46) | 25 (32) | 0.07 |
Diabetes mellitus | 23 (29) | 16 (20) | 0.20 |
Previous history of heart disease | 31 (39) | 20 (25) | 0.06 |
Previous history of myocardial infarction | 12 (15) | 5 (6) | 0.07 |
Previous history of chronic heart failure | 12 (15) | 9 (11) | 0.48 |
Cause of cardiac arrest | |||
Acute coronary syndrome | 35 (44) | 20 (25) | |
Old myocardial infarction | 8 (10) | 7 (9) | |
Cardiomyopathy | 8 (10) | 4 (5) | |
Spasm of coronary artery | 4 (5) | 1 (1) | |
Others | 18 (23) | 14 (21) | |
Unknown | 6 (8) | 33 (42) | |
Emergency coronary angiography | 44 (56) | 20 (25) | <0.01 |
Primary percutaneous coronary intervention | 23 (29) | 9 (11) | <0.01 |
Use of intra-aortic balloon pump | 44 (56) | 15 (19) | <0.001 |
Use of extracorporeal life-support | 21 (27) | 5 (6) | <0.001 |
Duration of hospital stay (days) | 16 (4 to 27) | 1 (0 to 11) | <0.001 |
Favorable neurological outcome | 24 (30) | 23 (29) | 0.86 |
Good cerebral performance | 24 (30) | 23 (29) | |
Coma or vegetative state | 6 (8) | 1 (1) | |
Dead | 49 (62) | 55 (70) | |
Thirty-day survival | 32 (41) | 23 (29) | 0.13 |
Predictor of neurological outcome
Discussion
Study limitations
Conclusions
Key messages
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MTH is more beneficial in patients whose CPA-ROSC is greater than 15 minutes.
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Neurological outcome in patients treated with normothermia and hypothermia were similar in patients with a CPA-ROSC less than 15 minutes.
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The CPA-ROSC is an independent predictor of neurological outcome in comatose survivors of cardiac arrest.
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A CPA-ROSC greater than 15 minutes in the normothermia therapy group and of 30 minutes in the hypothermia therapy group was associated with low rates of favorable neurological outcome.