Characteristics of 7292 individuals with new onset myocarditis (myocarditis associated with SARS-CoV-2 mRNA vaccination, myocarditis associated with covid-19 disease, and conventional myocarditis), in Denmark, Finland, Norway, and Sweden, 2018-22 (Nordic myocarditis cohort)
| Characteristics | Type of myocarditis | ||
| Vaccination | Covid-19 | Conventional | |
| Total No of patients | 530 (100.0) | 109 (100.0) | 6653 (100.0) |
| No of patients by country: | |||
| Denmark | 98 (18.5) | 8 (7.3) | 695 (10.4) |
| Finland | 140 (26.4) | 25 (22.9) | 2059 (30.9) |
| Norway | 109 (20.6) | 18 (16.5) | 1161 (17.5) |
| Sweden | 183 (34.5) | 58 (53.2) | 2738 (41.2) |
| Time period: | |||
| 2018-19 | 0 | 0 | 3820 (57.4) |
| 2020-22 | 530 (100.0) | 109 (100) | 2833 (42.6) |
| Age group (years): | |||
| 12-24 | 202 (38.1) | 19 (17.4) | 1620 (24.3) |
| 25-39 | 138 (26.0) | 29 (26.6) | 1707 (25.7) |
| ≥40 | 190 (35.8) | 61 (56.0) | 3326 (50.0) |
| Sex: | |||
| Women | 117 (22.1) | 33 (30.3) | 1838 (27.6) |
| Men | 413 (77.9) | 76 (69.7) | 4815 (72.4) |
| Length of initial admission to hospital (days): | |||
| ≤3 | 154 (29.1) | 21 (19.3) | 2069 (31.1) |
| 4-6 | 291 (54.9) | 34 (31.2) | 2691 (40.4) |
| ≥7 | 85 (16.0) | 54 (49.5) | 1893 (28.5) |
| Predisposing comorbidity: | |||
| Any* | 71 (13.4) | 12 (11.0) | 1100 (16.5) |
| None | 459 (86.6) | 97 (89.0) | 5553 (83.5) |
Values are numbers (percentages).
*Diagnosis of malignancy, cardiovascular disease, or autoimmune disease before admission to hospital for new onset myocarditis.