Table 1.
Baseline characteristics of IIM patients compared with those of normal controls
| Characteristics (units) | IIM patients (n = 44) | Healthy Controls (n = 30) | P value |
|---|---|---|---|
| Age (years) | 49.0 ± 12.0 | 48.2 ± 15.6 | 0.232 |
| Males, n (%) | 22 (50.0%) | 15 (50.0%) | 1.000 |
| BMI (kg/m2) | 22.4 ± 3.0 | 22.8 ± 2.8 | 0.465 |
| Systolic blood pressure, mmHg | 122 ± 14 | 121 ± 11 | 0.673 |
| Diastolic blood pressure, mmHg | 78 ± 8 | 72 ± 5 | 0.512 |
| Heart rate | 76.5 ± 9.7 | 74.1 ± 7.2 | 0.592 |
| Disease duration (years) | 0.5 (0.2, 2.0) | – | – |
| Clinical presentation | |||
| Proximal muscle weakness, n (%) | 41 (93.2%) | – | – |
| Rash, n (%) | 29 (65.9%) | – | – |
| Myalgia, n (%) | 23 (52.3%) | – | – |
| Dysphagia, n (%) | 17 (38.6%) | – | – |
| Comorbidity | |||
| Hypertension, n (%) | 6 (13.6%) | – | – |
| Diabetes, n (%) | 1 (2.3%) | – | – |
| Biomarkers | |||
| Hct | 0.40 ± 0.05 | 0.43 ± 0.03 | 0.003 |
| CRP (mg/L) | 4.3 (1.7–9.7) | – | – |
| ESR (mm/h) | 28 (23–47) | – | – |
| CK (U/L) | 316 (79–2202) | – | – |
| CK-MB (ng/mL) | 20.6 (5.3–54.0) | – | – |
| cTnT (g/L) | 96 (40–269) | – | – |
| NT-proBNP (pg/mL) | 226 (85–747) | – | – |
| Medication | |||
| Steroids, n (%) | 44 (100%) | – | – |
| Methotrexate, n (%) | 22 (50.0%) | – | – |
| Cyclophosphamide, n (%) | 12 (27.3%) | – | – |
| Chloroquine, n (%) | 18 (40.9%) | – | – |
| Azathioprine, n (%) | 4 (9.1%) | – | – |
| Cardiac structure and function | |||
| LVEDVi, mL/m2 | 82.7 ± 26.6 | 77.1 ± 13.3 | 0.300 |
| LVESVi, mL/m2 | 33.9 ± 25.1 | 29.1 ± 8.1 | 0.428 |
| LVEF (%) | 61.4 ± 11.8 | 62.0 ± 5.2 | 0.958 |
| LVmassi (g/m2) | 50.8 ± 15.0 | 43.6 ± 8.2 | 0.037 |
| RVEDVi, mL/m2 | 80.9 ± 22.2 | 68.7 ± 18.5 | 0.042 |
| RVESVi, mL/m2 | 38.2 ± 17.1 | 34. 3 ± 10.5 | 0.146 |
| RVEF (%) | 53.6 ± 9.8 | 57.2 ± 5.2 | 0.055 |
| Myocardial tissue characterization | |||
| T2w ratio | 1.3 ± 0.4 | 1.2 ± 0.4 | 0.259 |
| LGE, n (%) | 11 (25%) | 0 | – |
| LGE extent, % | 12.0 ± 3.1 | 0 | – |
| Native T1 mapping-myocardial, ms | 1275 ± 82 | 1199 ± 47 | < 0.001 |
| T2 mapping-myocardial, ms | 44.2 ± 4.0 | 38.3 ± 2.9 | < 0.001 |
| ECV-myocardial, % | 32.3 ± 6.2 | 26.6 ± 2.4 | < 0.001 |
| Skeletal tissue characterization | |||
| Native T1 mapping-skeletal, ms | 1287 ± 149 | 1107 ± 70 | < 0.001 |
| T2 mapping-skeletal, ms | 34.4 ± 3.1 | 26.0 ± 1.4 | < 0.001 |
| ECV-skeletal, % | 31.1 ± 12.8 | 13.6 ± 3.1 | < 0.001 |
Abbreviations: BMI body mass index, SBP systolic blood pressure, DBP diastolic blood pressure, HR heart rate, NYHA New York Heart Association functional classification, Hct hematocrit, CRP C-reactive protein, ESR erythrocyte sedimentation rate, CK creatine kinase, CK-MB creatine kinase-MB, TnT Troponins T, NT-proBNP N-terminal pro b-type natriuretic peptide, LVEDVi left ventricular end-diastolic volume index, LVESVi left ventricular end-systolic volume index, LVmassi left ventricular mass index, LVEF left ventricular ejection fraction, RVEDVi right ventricular end-diastolic volume index, RVESVi right ventricular end-systolic volume index, RVEF right ventricular ejection fraction, T2W T2-weighted ratio, LGE late gadolinium enhancement, ECV extracellular volume fraction
Values in bold indicate P values < 0.05
P values for comparison between IIM patients and normal controls