Table 1.
Baseline clinical characteristics of the study patients
| 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) |
Data presented as median (interquartile range) or n (%).