Table 1. Characteristics of the study patients according to baseline cardiac troponin I.
| Overall population(n = 343) | cTnI ≤ 0.046 µg/L(n = 255) | cTnI > 0.046 µg/L( n = 88) | P-value | |
| Data are presented as mean ± SD or median (range). AF: atrial fibrillation; ALT: alanine-transaminase; AST: aspartate transaminase; BP: blood pressure; CHF: chronic heart failure; CKD: chronic kidney disease; COPD: chronic obstructive pulmonary disease; CPK: creatine-phosphokinase; CRP: C-reactive protein; ICU: intensive care unit; INR: international normalized ratio; IL-6: interleuchin-6; MI: myocardial infarction; MV: mechanical ventilation; NIV: non-invasive ventilation; pO2: partial oxygen pressure; SpO2: oxygen saturation. | ||||
| Baseline and clinical characteristics | ||||
| Age, yrs | 75.0 (68.0−83.0) | 73.0 (66.0−81.0) | 81.0 (74.0−89.3) | < 0.001 |
| Male sex | 119 (34.7%) | 86 (33.7%) | 33 (37.5%) | 0.609 |
| CCI | 3.0 (2.0−4.0) | 3.0 (2.0−4.0) | 4.0 (3.0−4.0) | < 0.001 |
| Hypertension | 198 (58.1%) | 145 (57.3%) | 53 (60.2%) | 0.725 |
| Diabetes | 60 (17.6%) | 46 (18.2%) | 14 (16.1%) | 0.781 |
| Prior MI | 41 (12.1%) | 26 (10.4%) | 15 (17.0%) | 0.143 |
| CHF | 26 (8.2%) | 17 (7.1%) | 9 (11.5%) | 0.308 |
| AF | 40 (11.9%) | 24 (9.6%) | 16 (18.6%) | 0.041 |
| CKD | 29 (8.6%) | 14 (5.6%) | 15 (17.2%) | 0.002 |
| Neurological disorder | 36 (10.7%) | 18 (7.1%) | 18 (20.9%) | 0.001 |
| COPD | 41 (12.2%) | 32 (12.8%) | 9 (10.3%) | 0.680 |
| Cancer | 38 (11.3%) | 24 (9.6%) | 14 (16.3%) | 0.136 |
| Symptoms and signs | ||||
| Fever, °C | 37.7 (36.8−38.3) | 37.7 (36.8−38.3) | 37.8 (36.6−38.3) | 0.721 |
| Dyspnoea | 179 (52.8%) | 131 (52.0%) | 48 (55.2%) | 0.697 |
| Cough | 138 (40.7%) | 109 (43.3%) | 29 (33.3%) | 0.134 |
| Heart rate, per min | 88.0 (77.0−100.0) | 87.0 (77.5−99.5) | 90.0 (76.8−102.5) | 0.142 |
| Respiratory rate, per min | 20.0 (18.0−28.0) | 20.0 (18.0−28.0) | 22.0 (18.0−28.0) | 0.481 |
| Systolic BP, mmHg | 130.0 (120.0−150.0) | 130.0 (120.0−150.0) | 130.0 (116.5−145.0) | 0.179 |
| Diastolic BP, mmHg | 75.0 (70.0−85.0) | 75.0 (70.0−85.0) | 75.5 (67.3−80.0) | 0.651 |
| Laboratory findings | ||||
| SpO2 | 94.0% (90.0%−97.0%) | 94.0% (91.0%−97.0%) | 90.5% (85.0%−96.0%) | < 0.001 |
| Arterial pO2, mmHg | 67.1 (55.0−84.3) | 68.5 (58.5−86.0) | 57.0 (48.0−73.0) | 0.001 |
| Creatinine, mg/dL | 1.0 (0.8−1.3) | 1.0 (0.8−1.2) | 1.1 (0.9−1.8) | < 0.001 |
| Haemoglobin, g/L | 134.0 (120.0−147.0) | 135.0 (123.5−148.0) | 127.5 (114.0−143.0) | 0.013 |
| Platelets, × 109/L | 177.0 (134.0−240.5) | 174.0 (135.5−234.5) | 184.0 (130.8−268.5) | 0.196 |
| White blood cells, × 109 /L | 6.4 (4.8−9.4) | 6.2 (4.7−8.2) | 8.1 (5.3−13.1) | < 0.001 |
| Lymphocytes, × 109 /L | 0.8 (0.6−1.1) | 0.8 (0.6−1.1) | 0.8 (0.5−1.0) | 0.163 |
| ALT, IU/L | 30.0 (22.0−47.0) | 30.0 (21.5−47.0) | 30.0 (22.5−46.5) | 0.803 |
| AST, IU/L | 38.5 (26.3−58.0) | 37.5 (26.0−54.0) | 47.0 (29.8−78.3) | 0.021 |
| Total bilirubin, mg/dL | 0.5 (0.4−0.7) | 0.5 (0.4−0.7) | 0.6 (0.4−0.9) | 0.034 |
| INR | 1.2 (1.1−1.3) | 1.2 (1.1−1.3) | 1.3 (1.2−1.4) | 0.001 |
| CRP, mg/L | 93.4 (43.1−136.0) | 87.0 (42.3−134.0) | 106.0 (52.2−160.0) | 0.076 |
| IL-6, pg/mL | 50.7 (23.1−95.9) | 46.0 (21.1−82.3) | 75.6 (37.4−146.3) | < 0.001 |
| Fibrinogen, mg/dL | 5.7 (4.5−7.1) | 5.7 (4.6−7.3) | 5.3 (4.1−7.0) | 0.128 |
| D-dimer, ng/mL | 1081.0 (677.0−1704.3) | 970.0 (622.1−1459.0) | 1627.5 (1070.2−4333.3) | < 0.001 |
| CPK, µg/L | 126.5 (70.8−293.3) | 114.0 (69.0−203.0) | 186.00 (93.0−516.5) | < 0.001 |
| Critically ill | ||||
| No ventilation support | 183 (53.7%) | 128 (50.6%) | 55 (62.5%) | 0.152 |
| NIV | 98 (28.7%) | 77 (30.4%) | 21 (23.9%) | |
| MV | 60 (17.6%) | 48 (19.0%) | 12 (13.6%) | |
| MV duration, days | 10.0 (5.5−18.0) | 12.0 (5.0−19.0) | 8.0 (6.0−10.5) | 0.329 |
| Admitted to ICU | 64 (18.8%) | 51 (20.2%) | 13 (14.8%) | 0.339 |