Baseline characteristics
| Total | All counties | Stockholm only | |||||
| Control period | Pandemic | P value | Control period | Pandemic | P value | ||
| N (%) | 17 656 | 15 213 (86.2) | 2443 (13.8) | 2597 (87.0) | 387 (13.0) | ||
| Age (years), median (IQR) | 70 (61–77) | 70 (61–77) | 70 (61–77) | 0.25 | 68 (59–76) | 68 (59–75) | 0.36 |
| Men, n (%) | 11 894 (67.4) | 10 248 (67.4) | 1646 (67.4) | 0.99 | 1805 (69.5) | 274 (70.8) | 0.60 |
| Women, n (%) | 5762 (32.6) | 4965 (32.6) | 797 (32.6) | 792 (30.5) | 113 (29.2) | ||
| BMI, median (IQR) | 26.8 (24.2–30.9) | 26.8 (24.2–30.0) | 26.9 (24.3–30.1) | 0.08 | 26.8 (24.2–30.0) | 26.9 (24.1–30.1) | 0.98 |
| Current smoker, n (%) | 3376 (19.1) | 2928 (19.3) | 448 (18.3) | 0.57 | 507 (19.5) | 69 (17.8) | 0.26 |
| Medical history | |||||||
| Diabetes, n (%) | 3804 (21.6) | 3277 (21.5) | 527 (21.6) | 0.09 | 594 (22.9) | 81 (20.9) | 0.46 |
| Hypertension, n (%) | 10 329 (59.1) | 8967 (58.9) | 1462 (59.8) | 0.04 | 1529 (58.9) | 221 (57.1) | 0.2 |
| Hyperlipidaemia, n (%) | 6972 (39.5) | 6043 (39.7) | 929 (38.0) | 0.03 | 990 (38.1) | 131 (33.9) | 0.26 |
| MI, n (%) | 3801 (21.5) | 3322 (21.8) | 479 (19.6) | ≤0.001 | 583 (22.5) | 77 (19.9) | 0.15 |
| PCI, n (%) | 3099 (17.6) | 2659 (17.5) | 449 (18.0) | 0.66 | 451 (17.4) | 72 (18.6) | 0.55 |
| CABG, n (%) | 1140 (6.5) | 1014 (6.7) | 126 (5.2) | 0.002 | 167 (6.4) | 15 (3.9) | 0.005 |
| In-hospital characteristics | |||||||
| STEMI, n (%) | 6713 (38.0) | 5814 (38.2) | 899 (36.8) | 0.18 | 933 (35.9) | 144 (37.2) | 0.62 |
| NSTEMI, n (%) | 10 943 (62.0) | 9399 (61.8) | 1544 (63.2) | 0.18 | 1664 (64.1) | 243 (62.8) | 0.62 |
| STEMI after cardiac arrest, n (%) | 310 (1.8) | 270 (1.8) | 40 (1.6) | 0.63 | 53 (2.0) | 7 (1.8) | 0.76 |
| Time from symptom to PCI (min), median (IQR) | 930 (200–2461) | 931 (200–2495) | 820 (198–2130) | 0.04 | 948 (180–2299) | 797 (225–1822) | 0.55 |
| Time from first ECG to PCI (min), median (IQR) | 650 (83–1890) | 646 (83–1926) | 582 (79–1599) | 0.01 | 721 (77–1725) | 806 (77–1527) | 0.59 |
| Duty hours, n (%) | 10 806 (61.2) | 9281 (61.0) | 1525 (62.4) | 0.11 | 1649 (63.5) | 231 (59.7) | 0.003 |
| Killip class, n (%) | |||||||
| 1 | 14 221 (80.5) | 12 234 (80.4) | 1987 (81.3) | 0.29 | 1895 (73.0) | 293 (75.7) | 0.83 |
| 2 | 562 (3.2) | 489 (3.2) | 73 (3.0) | 84 (3.2) | 11 (2.8) | ||
| 3 | 164 (0.9) | 150 (1.0) | 14 (0.6) | 27 (1.0) | 3 (0.8) | ||
| 4 | 256 (1.5) | 218 (1.4) | 38 (1.6) | 45 (1.7) | 7 (1.8) | ||
| High-sensitivity troponin T (ng/L), median (IQR) | 560 (155–2133) | 574 (157–2144) | 538 (146–2210) | 0.85 | 578 (152–2289) | 516 (126–2310) | 0.70 |
| Angiographic findings, n (%) | |||||||
| Normal/atheromatosis | 2622 (14.9) | 2211 (14.5) | 411 (16.8) | ≤0.001 | 466 (17.9) | 71 (18.4) | 0.26 |
| 1VD not LM | 6553 (37.1) | 5611 (37.9) | 942 (38.6) | 990 (38.1) | 165 (42.6) | ||
| 2VD not LM | 4012 (22.7) | 3444 (22.6) | 568 (23.3) | 521 (20.1) | 79 (20.4) | ||
| 3VD not LM | 3059 (17.3) | 2710 (17.8) | 349 (14.3) | 417 (16.1) | 46 (11.9) | ||
| LM or LM including 1-3VD | 1376 (7.8) | 1210 (8.0) | 166 (6.8) | 199 (7.7) | 25 (6.5) | ||
| PCI, n (%) | 11 696 (66.2) | 10 049 (66.1) | 1647 (67.4) | 0.19 | 1651 (63.6) | 261 (67.4) | 0.14 |
| Primary decision CABG, n (%) | 1017 (5.8) | 911 (6.0) | 106 (4.3) | ≤0.001 | 114 (4.4) | 8 (2.1) | 0.03 |
BMI, body mass index; CABG, coronary artery bypass grafting; LM, left main coronary artery; MI, myocardial infarction; NSTEMI, non-ST-elevation myocardial infarction; PCI, percutaneous coronary intervention; STEMI, ST-elevation myocardial infarction; VD, vessel disease.