Table 3.
Clinical characteristics of mRNA vaccine‐related myocarditis patients according to recovery course
| Total mRNA vaccines (n = 74) | BNT162b2 (n = 58)a | |||||
|---|---|---|---|---|---|---|
| Medical treatment (n = 47) | Conservative careb (n = 26) | p value | Medical treatment (n = 38) | Conservative care b (n = 20) | p value | |
| Number of patients (%) or median (range) | Number of patients (%) or median (range) | Number of patients (%) or median (range) | Number of patients (%) or median (range) | |||
| Demographic variables | ||||||
| Age, years | 22.0 [14.0–67.0] | 23.5 [16.2–56.0] | 0.668 | 20.0 [14.0–45.0] | 20.8 [16.2–56.0] | 0.587 |
| Male | 46/47 (97.9) | 24/26 (92.3) | 0.287 | 38/38 (100.0) | 19/20 (95.0) | 0.345 |
| Underlying disease | 6/46 (13.0) | 0/16 (0.0) | 0.325 | 3/37 (8.1) | 0/13 (0.0) | 0.558 |
| COVID‐19‐related variables | ||||||
| Previous COVID‐19 infection | 5/37 (13.5) | 3/7 (42.9) | 0.100 | 4/28 (14.3) | 3/4 (75.0) | 0.025 |
| Presentation after second dose | 43/47 (91.5) | 23/26 (88.5) | 0.694 | 35/38 (92.1) | 17/20 (85.0) | 0.405 |
| Type of vaccine | 0.766 | |||||
| mRNA‐1273 | 9/47 (19.1) | 6/26 (23.1) | ||||
| BNT162b2 | 38/47 (80.9) | 20/26 (76.9) | ||||
| Clinical manifestations | ||||||
| Interval after vaccination, days | 3.00 [0.25–16.00] | 3.00 [1.00–6.00] | 0.834 | 2.00 [0.25–16.00] | 3.00 [1.00–6.00] | 0.609 |
| Symptoms with 24 h of vaccinationc | 19/25 (76.0) | 4/7 (57.1) | 0.370 | 11/17 (64.7) | 2/4 (50.0) | 0.618 |
| Chest pain | 45/47 (95.7) | 25/26 (96.2) | 1.000 | 38/38 (100.0) | 19/20 (95.0) | 0.345 |
| Fatigue | 7/47 (14.9) | 1/26 (3.8) | 0.245 | 6/38 (15.8) | 1/20 (5.0) | 0.403 |
| Fever | 16/47 (34.0) | 9/26 (34.6) | 1.000 | 12/38 (31.6) | 8/20 (40.0) | 0.570 |
| Nausea | 7/47 (14.9) | 1/26 (3.8) | 0.245 | 5/38 (13.2) | 1/20 (5.0) | 0.653 |
| Electrocardiography | ||||||
| Abnormal ECG | 44/47 (93.6) | 20/26 (76.9) | 0.061 | 37/38 (97.4) | 15/20 (75.0) | 0.016 |
| Non‐sinus rhythm | 6/47 (12.8) | 0/26 (0.0) | 0.083 | 4/38 (10.5) | 0/20 (0.0) | 0.288 |
| ST changes | 38/47 (80.9) | 18/26 (69.2) | 0.386 | 33/38 (86.8) | 13/20 (65.0) | 0.086 |
| Echocardiography | ||||||
| LV dysfunctiond | 19/47 (40.4) | 3/26 (11.5) | 0.015 | 14/38 (36.8) | 0/20 (0.0) | 0.001 |
| RWMA | 15/32 (46.9) | 5/10 (50.0) | 1.000 | 11/24 (45.8) | 1/4 (25.0) | 0.613 |
| Laboratory findings | ||||||
| Elevated BNPe | 8/17 (47.1) | 3/4 (75.0) | 0.586 | 7/13 (53.8) | 3/4 (75.0) | 0.603 |
| Elevated CRP | 40/44 (90.9) | 24/25 (96.0) | 0.646 | 32/36 (88.9) | 18/19 (94.7) | 0.649 |
| MRI findings | ||||||
| Late gadolinium enhancement | 40/41 (97.6) | 12/15 (80.0) | 0.055 | 34/35 (97.1) | 9/12 (75.0) | 0.046 |
| Hyperemia or myocardial fibrosis on T1 | 42/43 (97.7) | 14/15 (93.3) | 0.454 | 35/36 (97.2) | 11/12 (91.7) | 0.441 |
| Myocardial edema on T2 | 32/39 (82.1) | 7/14 (50.0) | 0.033 | 28/35 (80.0) | 5/12 (41.7) | 0.025 |
| Outcome | ||||||
| Complicationf | 3/47 (6.4) | 1/26 (3.8) | 1.000 | 2/38 (5.3) | 0/20 (0.0) | 0.540 |
| ICU admission | 12/47 (25.5) | 0/26 (0.0) | 0.006 | 11/38 (28.9) | 0/20 (0.0) | 0.011 |
| Hospital stay < 4 days | 17/40 (42.5) | 14/23 (60.9) | 0.196 | 12/33 (36.4) | 10/19 (52.6) | 0.382 |
Abbreviations: BNP, B‐type natriuretic peptide; COVID‐19, coronavirus disease 2019; CRP, C‐reactive protein; ECG, Electrocardiography; ICU, intensive care unit; IVIG, intravenous immunoglobulin; LVEF, left ventricular ejection fraction; NSAID, nonsteroidal anti‐inflammatory drugs; NT‐proBNP, N‐terminal‐pro‐BNP; RWMA, regional wall motional abnormality.
mRNA‐1273 vaccine did not show any significant difference in parameters between spontaneous recovery and medical treatment groups.
Patients who recovered without medical treatments such as anti‐inflammatory agents or heart failure treatment.
Systemic symptoms (fever, chill, myalgia, and generalized body ache) within 24 h after vaccine administration.
LVEF less than 55%.
Included in this category if patient has elevated levels of BNP, proBNP, or NT‐proBNP.
Multiorgan failure (n = 1) and cardiac arrhythmia (n = 3) during hospitalization.