Table 1. Baseline characteristics for patients with IIM and AVM.
| Variables | IIM (n=46) | AVM (n=24) | P value |
|---|---|---|---|
| Demographics | |||
| Age (years), mean ± SD | 48±16 | 28±12†‡ | <0.001 |
| Male | 14 (30.4%) | 12 (50%) | 0.108 |
| BMI (kg/m2), mean ± SD | 20.8±6.0 | 23.7±3.6 | 0.046 |
| Smoking | 11 (23.9%) | 6 (25%) | 0.920 |
| Hypertension | 16 (34.7%) | 0 (0%)† | 0.001 |
| Diabetes mellitus | 5 (10.8%) | 0 (0%) | 0.235 |
| Hyperlipidemia | 10 (21.7%) | 2 (8.3%) | 0.281 |
| Clinical characteristics | |||
| Interstitial lung disease | 22 (47.8%) | 0 (0%)†‡ | <0.001 |
| Dysphagia | 9 (19.5%) | 0 (0%)‡ | 0.052 |
| Respiratory muscular involvement | 4 (8.6%) | 0 (0%) | 0.344 |
| Raynaud phenomenon | 4 (8.6%) | 0 (0%) | 0.344 |
| Shortness of breath | 27 (58.6%) | 18 (75.0%)‡ | 0.177 |
| Palpitation | 16 (34.7%) | 6 (25.0%)† | 0.403 |
| Nonproductive cough | 4 (8.6%) | 2 (8.3%) | 0.959 |
| Chest pain | 3 (6.5%) | 12 (50%)†‡ | <0.001 |
| Arrhythmias | 21 (45.6%) | 6 (25.0%) | 0.092 |
| Muscle strength grading of MMT | |||
| Proximal upper extremities, mean ± SD | 4.2±0.8 | NA | NA |
| Distal upper extremities, mean ± SD | 4.9±0.3 | NA | NA |
| Proximal lower extremities, mean ± SD | 4.0±0.8 | NA | NA |
| Distal lower extremities, mean ± SD | 4.9±0.4 | NA | NA |
| Proximal muscle weakness, mean ± SD | 31 (67.3%) | NA | NA |
| Laboratory tests | |||
| ALT (U/L), median [IQR] | 65 [124] | 161 [340] | 0.041 |
| AST (U/L), median [IQR] | 68 [113] | 65 [104] | 0.877 |
| LDH (U/L), median [IQR] | 419 [388] | 376 [408] | 0.584 |
| Creatinine (µmol/L), median [IQR] | 50 [29] | 99 [41]† | 0.007 |
| ESR (mm/h), median [IQR] | 16 [27] | 14 [25] | 0.314 |
| CRP (mg/L), median [IQR] | 7 [17] | 21 [31] | 0.033 |
| Creatine kinase (U/L), median [IQR] | 1,293 [3,497] | 314 [436] | 0.863 |
| Creatine kinase-MB (U/L), median [IQR] | 39 [140] | 22 [67] | 0.369 |
| cTnI (pg/mL), median [IQR] | 1.8 [3.3] | 4.1 [5.6] | 0.611 |
| NT-proBNP (pg/mL), median [IQR] | 1,081 [2,067] | 2,147 [3,762]† | 0.014 |
| Antinuclear antibody | 31 (67.3%) | NA | NA |
| Myositis specific antibodies | |||
| Anti-Jo-1/PL-7/EJ/OJ | 13 (28.2%) | NA | NA |
| Anti-Mi-2/TIF1γ/MDA5/NXP2 | 10 (21.7%) | NA | NA |
| Anti-SRP | 4 (8.7%) | NA | NA |
| Myositis associated antibodies | |||
| Anti-Ro52 | 21 (45.6%) | NA | NA |
| Anti-Ku | 5 (10.9%) | NA | NA |
| Anti-PM-Scl 100/PM-Scl 75 | 0 (0%) | NA | NA |
| Treatment | |||
| Long-term glucocorticoids | 46 (100%) | NA | NA |
| Glucocorticoids pulse-treatment | 14 (30.4%) | NA | NA |
| Immunosuppressive agents | 41 (89.1%) | NA | NA |
| Intravenous immune globulin | 16 (34.8%) | NA | NA |
†, P<0.05 versus PM; ‡, P<0.05 versus DM. IIM, idiopathic inflammatory myopathies; AVM, acute viral myocarditis; BMI, body mass index; MMT, Manual Muscle Testing; ALT, alanine aminotransferase; AST, aspartate aminotransferase; LDH, lactate dehydrogenase; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; cTnI, cardiac troponin I; NT-proBNP, N-terminal pro-B-type natriuretic peptide; PM, polymyositis; DM, dermatomyositis.