Table 1.
Clinical and cardiac magnetic resonance imaging (MRI) characteristics of pediatric and adolescent patients with acute myocarditis and control patients
| Variable | Patients (n=43) | Controls (n=16) | P-value |
|---|---|---|---|
| Clinical parameters | |||
| Age (years) | 17±3 | 17±4 | 0.35 |
| Men | 33 (77%) | 8 (50%) | 0.061 |
| Weight (kg) | 72±19 | 61±20 | 0.068 |
| Height (cm) | 168±17 | 160±16 | 0.10 |
| Heart rate (bpm) | 73±15 | 76±10 | 0.46 |
| Hematocrit (%) | 39±6 | 39±3 | 0.67 |
| Elevated troponin | 40 (93%) | 0 (0%) | <0.001 |
| White blood cell count (103/μL) | 10.8±5.0 | 8.6±1.6 | 0.021 |
| C-reactive protein (mg/L) | 62±1 | 2±2 | <0.001 |
| General cardiac MRI parameters | |||
| Left ventricular ejection fraction (%) | 57±8 | 59±5 | 0.32 |
| Left ventricular end-diastolic volume index (mL/m2) | 83±15 | 78±12 | 0.17 |
| Cardiac index (L/min/m2) | 3.3±0.6 | 3.4±0.5 | 0.72 |
| Interventricular septal thickness (mm) | 8.3±1.4 | 7.5±1.4 | 0.20 |
| Pericardial effusion | 17 (40%) | 0 (0%) | <0.001 |
| T2 signal intensity ratio | 2.10±0.49 | 1.54±0.29 | <0.001 |
| Visual focal myocardial edema | 32 (74%) | 0 (0%) | <0.001 |
| Visual late gadolinium enhancement | 36 (84%) | 0 (0%) | <0.001 |
| Mapping cardiac MRI parameters | |||
| T1 relaxation time, native (ms) | 1,031±46 | 962±17 | <0.001 |
| Extracellular volume fraction (%) | 29.2±5.9 | 26.5±2.8 | 0.058 |
| T2 relaxation time (ms) | 58±5 | 51±2 | <0.001 |
Continuous variables are given as mean±standard deviation. Dichotomous variables are given as absolute frequency with percentages in parentheses. P-values were obtained using a Student’s t-test, χ2 test (cell count >5) or Fisher exact test (cell count ≤5). T1 and T2 relaxation times and extracellular volume fraction were available in 26/43 patients and all controls