Table 2.
Cardiac Testing Among Patients With Classic Myocarditis, MIS‐C Myocarditis, and Vaccine‐Related Myocarditis
| Variable | Level | No. | Overall (N=201) | Classic myocarditis (n=43) | MIS‐C (n=149) | Vaccine‐related myocarditis (n=9) | P value |
|---|---|---|---|---|---|---|---|
| Left ventricular ejection fraction at presentation, categorized | 1: <30% | 201 | 7 (3.5) | 4 (9.3) | 3 (2.0) | 0 (0) | 0.066 |
| 2: 30%–55% | 82 (40.8) | 21 (48.8) | 59 (39.6) | 2 (22.2) | |||
| 3: >55% | 112 (55.7) | 18 (41.9) | 87 (58.4) | 7 (77.8) | |||
| Left ventricular ejection fraction at presentation | 201 | 56 (46, 64) | 51.0 (38.0, 61.0) | 56.2 (48, 64.8) | 59.7 (57.8, 67.2) | 0.019 * | |
| Lowest recorded EF | 201 | 50.2 (39, 58.6) | 45.3 (29.4, 60) | 50.2 (40.0, 57.6) | 59.7 (57.8, 67.2) | 0.013 * | |
| Normal EF at the time of discharge | Yes * | 201 | 178 (88.6) | 30 (73.2) | 139 (93.3) | 9 (100.0) | <0.001 * |
| Coronary artery dilation at time of presentation | No | 199 | 186 (93.5) | 42 (97.7) | 135 (91.8) | 9 (100.0) | 0.440 |
| Coronary artery dilation at discharge | No | 199 | 191 (96.0) | 41 (97.6) | 141 (95.3) | 9 (100.0) | 0.786 |
| Presence of pericardial effusion | Absent | 201 | 102 (50.7) | 22 (51.2) | 72 (48.3) | 8 (88.9) | 0.005 * |
| Present | 99 (49.3) | 21 (48.8) | 77 (51.7) | 1 (11) | |||
| ECG findings at admission | Normal | 198 | 125 (63.1) | 12 (27.9) | 110 (73.8) | 3 (33.3) | <0.001 * |
| Complete AV block | 3 (1.5) | 3 (7.0) | 0 (0) | 0 (0) | |||
| Repolarization abnormalities | 58 (29.3) | 25 (58.1) | 27 (18.5) | 6 (66.7) | |||
| Other † | 12 (6.1) | 3 (7.0) | 9 (6.2) | 0 (0) | |||
| ECG findings at clinic follow‐up, 1–2 wk after discharge | Normal | 183 | 168 (91.8) | 29 (74.4) | 134 (97.1) | 5 (83.3) | <0.001 * |
| Repolarization abnormalities | 5 (2.7) | 3 (7.7) | 1 (0.7) | 1 (16.7) | |||
| Other † | 10 (5.5) | 7 (17.9) | 3 (2.2) | 0 (0) |
Data are provided as number, median (quartile 1, quartile 3), or number (percentage). AV indicates atrioventricular; EF, ejection fraction; and MIS‐C, multisystem inflammatory syndrome in children.
*
Indicates significance at P < 0.05 level.
†
The EF at the time of discharge for 2 additional patients with classic myocarditis, 1 who died and 1 who progressed to transplant, are not included in this row of the table.
‡
Other ECG findings included Brugada pattern, atrial tachyarrhythmia, markedly abnormal ventricular axis, junctional tachycardia, and abnormal intervals (ie, prolonged QTc and PR).