Table 1.
Baseline and procedure characteristics
| All (n = 603) |
Direct admission (n = 441) |
Inter-facility transfer (n = 162) |
P value | |
|---|---|---|---|---|
| Demographic characteristics and history | ||||
| Age, years (mean [SD]) | 67.9 (12.5) | 68.0 (12.3) | 67.4 (13.1) | 0.564 |
| ≥75 years, n (%) | 192 (31.8) | 140 (31.8) | 52 (32.1) | 0.934 |
| Women, n (%) | 138 (22.9) | 95 (21.5) | 43 (26.5) | 0.195 |
| Previous MI, n (%) | 69 (11.4) | 55 (12.5) | 14 (8.6) | 0.329 |
| Presentation at PCI facility | ||||
| JCS on arrival | ||||
| 0/I, n (%) | 558 (92.5) | 403 (91.4) | 155 (95.7) | 0.085 |
| II/III, n (%) | 30 (5.0) | 27 (6.1) | 3 (1.9) | |
| Unknown, n (%) | 15 (2.5) | 11 (2.5) | 4 (2.5) | |
| Killip class on arrival | ||||
| 1/2, n (%) | 418 (69.3) | 301 (68.3) | 117 (72.2) | 0.639 |
| 3/4, n (%) | 88(14.6) | 67 (15.2) | 21 (13.0) | |
| Unknown, n (%) | 97 (16.1) | 73 (16.6) | 24 (14.8) | |
| Comparison of situations at symptom onset | ||||
| Location at STEMI onset | ||||
| Urban medical regions, n (%) | 311 (51.6) | 265 (60.1) | 46 (28.4) | <0.001* |
| Rural medical regions, n (%) | 292 (48.4) | 176 (39.9) | 116 (71.6) | |
| Witness | ||||
| Yes, n (%) | 311 (51.6) | 237 (53.7) | 74 (45.7) | 0.079 |
| No, n (%) | 292 (48.4) | 204 (46.3) | 88 (54.3) | |
| Season | ||||
| Summer, n (%) | 282 (46.8) | 202 (45.8) | 80 (49.4) | 0.462 |
| Winter, n (%) | 321 (53.2) | 239 (54.2) | 82 (50.6) | |
| Day of onset | ||||
| Weekday, n (%) | 416 (69.2) | 307 (69.9) | 109 (67.3) | 0.533 |
| Weekend or holiday, n (%) | 185 (30.8) | 132 (30.1) | 53 (32.7) | |
| Time of onset | ||||
| Daytime, n (%) | 365 (60.5) | 261 (59.2) | 104 (64.2) | 0.264 |
| Nighttime, n (%) | 238 (39.5) | 180 (40.8) | 58 (35.8) | |
| Transport path | ||||
| EMS call | ||||
| Yes, n (%) | 405 (67.2) | 345 (78.2) | 60 (37.0) | <0.001* |
| No, n (%) | 198 (32.8) | 96 (21.8) | 102 (63.0) | |
| Use of air transportation, n (%) | 7 (1.2) | 0 | 7 (4.2) | – |
| Mechanical support/interventions additional to primary PCI | ||||
| IABP, n (%) | 71 (11.8) | 53 (12.0) | 18 (11.1) | 0.887 |
| CABG,n (%) | 10 (1.7) | 7 (1.6) | 3 (1.9) | 0.733 |
| Time course | ||||
| TIT, min (median [IQR]) | 185 (125, 290) | 160 (114, 255) | 259 (170, 359) | <0.001* |
| ODT, min (median [IQR]) | 104 (56, 204) | 80 (50, 153) | 197 (120, 305) | <0.001* |
| ODT ≤ 120 min achieved, n (%) | 339 (56.2) | 298 (67.6) | 41 (25.3) | <0.001* |
| DBT, min (median [IQR]) | 63 (44, 90) | 67 (47, 95) | 54 (35, 70) | <0.001* |
| DBT ≤ 90 min achieved, n (%) | 454 (75.3) | 318 (72.1) | 136 (84.0) | 0.003* |
| FMCTB, min (median [IQR]) | 98 (71, 144) | 88 (66, 200) | 130 (95, 193) | <0.001* |
| FMCTB ≤ 120 min achieved, n (%) | 405 (67.2) | 332 (75.3) | 73 (45.1) | <0.001* |
| DIDO, min (median [IQR]) | 40 (13, 72) | – | 40 (13, 72) | |
| Outcome | ||||
| Death (CPC 5), n (%) | 38 (6.3) | 26 (5.9) | 12 (7.4) | 0.498 |
| Poor (CPC 3-5), n (%) | 55 (9.1) | 38 (8.6) | 17 (10.5) | 0.478 |
| Good (CPC 1-2), n (%) | 548 (90.9) | 403 (91.4) | 145 (89.5) | |
We compared categorical variables using the χ2 test or Fisher's exact test and continuous variables using Student's t-test or the Wilcoxon rank-sum test. Variables are expressed as numbers (%), means (SD: standard deviation), or medians (IQR; interquartile ranges). MI, myocardial infarction; JCS, Japan Coma Scale; urban medical regions, Sapporo, Kamikawa Chubu, and Minami Oshima medical regions; rural medical regions, regions outside the urban medical regions; Daytime, 6:00 a.m–6:00 p.m; Nighttime, 6:00 p.m–6:00 a.m; EMS, emergency medical services; PCI, percutaneous coronary intervention, IABP, intra-aortic balloon pump therapy; CABG, coronary artery bypass grafting; TIT, total ischemic time; ODT, onset-to-door time; DBT, door-to-balloon time; FMCTB, first-medical-contact-to-balloon time; DIDO, door-in-to-door-out time; CPC, cerebral performance category
*P < 0.05