Table 3. Characteristics of CMR in patients with myocarditis related to IIMs.
| CMR | Total (N=31) | AMA-M2 (+) (N=12) | AMA-M2 (–) (N=19) | P value |
|---|---|---|---|---|
| Left atrial enlargement, n (%) | 14 (45.2) | 7 (58.3) | 7 (36.8) | 0.241 |
| Right atrial enlargement, n (%) | 18 (58.1) | 10 (83.3) | 8 (42.1) | 0.032 |
| Left ventricular enlargement, n (%) | 19 (61.3) | 9 (75.0) | 10 (52.6) | 0.206 |
| Right ventricular enlargement, n (%) | 14 (45.2) | 7 (58.3) | 7 (36.8) | 0.241 |
| Pericardial effusion, n (%) | 19 (61.3) | 5 (41.7) | 14 (73.7) | 0.557 |
| LVEF (mean ± SD, %) | 37.9±16.2 | 29.2±12.6 | 43.4±16.1 | 0.015 |
| LVEDVI (mean ± SD, mL/m2) | 106.8±36.8 | 123.9±35.5 | 96.9±34.7 | 0.051 |
| LVCO (L/min) | 4.2±1.4 | 3.2±1.3 | 4.6±1.3 | 0.020 |
| RVEF (mean ± SD, %) | 40.4±18.8 | 28.8±15.6 | 47.2±17.5 | 0.006 |
| RVEDVI (mean ± SD, mL/m2) | 92.7±36.1 | 106.6±33.2 | 84.7±36.0 | 0.111 |
| RVCO (mean ± SD, L/min) | 3.9±1.5 | 3.1±1.1 | 4.3±1.5 | 0.057 |
| T2-weighted edema in myocardium, n (%) | 13 (21.0) | 6 (50.0) | 7 (36.8) | 0.421 |
| Myocardial EGE, n (%) | 11 (35.5) | 4 (33.3) | 7 (36.8) | 1.000 |
| Positive segments of LGE, n (%) | ||||
| Basal segments | 23 (74.2) | 9 (75.0) | 14 (73.7) | 1.000 |
| Mid-cavity segments | 22 (71.0) | 8 (66.7) | 14 (73.7) | 0.704 |
| Apical segments | 18 (58.1) | 5 (41.7) | 13 (68.4) | 0.161 |
| Apex segment | 8 (25.8) | 4 (33.3) | 4 (21.1) | 0.676 |
| Diffuse LGE, n (%) | 17 (54.8) | 10 (83.3) | 7 (36.8) | 0.024 |
| Subendocardial LGE positive segments, n (%) | 16 (51.6) | 7 (58.3) | 9 (47.4) | 0.716 |
| Intramural LGE positive segments, n (%) | 17 (54.8) | 6 (50.0) | 11 (57.9) | 0.667 |
| Subepicardial LGE positive segments, n (%) | 6 (19.4) | 3 (25.0) | 3 (15.8) | 0.653 |
In patients with myocarditis related to IIMs, values are compared according to positive or negative AMA-M2 antibodies, using independent sample t-test, Mann-Whitney U or Fisher’s exact test, as appropriate. IIMs, idiopathic inflammatory myopathies; CMR, Cardiovascular Magnetic Resonance; AMA-M2, anti-mitochondrial antibody M2; LVEF, left ventricular ejection factor; SD, standard deviation; LVEDVI, left ventricular end-diastolic volume index; LVCO, left ventricular cardiac output; RVEF, right ventricular ejection factor; RVEDVI, right ventricular end-diastolic volume index; RVCO, right ventricular cardiac output; EGE, early gadolinium enhancement; LGE, late gadolinium enhancement.