Table 1.
Clinical characteristics of the population
| All | Control | COVID-19 | P-value | |
|---|---|---|---|---|
| N = 37 | N = 10 | N = 27 | ||
| Demographics | ||||
| Age, years | 57.3 ± 9.5 | 57.9 ± 7.8 | 57.1 ± 10.2 | 0.827 |
| Sex | ||||
| Male | 22 (59%) | 8 (80%) | 14 (52%) | 0.153 |
| Female | 15 (41%) | 2 (20%) | 13 (48%) | |
| Healthcare worker | 5 (14%) | 1 (10%) | 4 (15%) | 1.000 |
| Most deprived SIMD quintile | 13 (37%) | 2 (20%) | 11 (44%) | 0.259 |
| Ethnicity | ||||
| White | 35 (95%) | 10 (100%) | 25 (93%) | 1.000 |
| Asian | 1 (3%) | 0 (0%) | 1 (4%) | |
| Other | 1 (3%) | 0 (0%) | 1 (4%) | |
| Presenting characteristics at enrolment a | ||||
| Weight, kg | 92 ± 18 | 93 ± 12 | 91 ± 20 | 0.749 |
| Height, cm | 172 ± 9 | 176 ± 8 | 170 ± 9 | 0.086 |
| Body mass index, kg/m2 | 31.1 ± 5.8 | 30.2 ± 4.1 | 31.4 ± 6.4 | 0.567 |
| Body surface area, m2 | 2.1 ± 0.2 | 2.1 ± 0.2 | 2.1 ± 0.3 | 0.447 |
| Heart rate, b.p.m. | 88 ± 21 | 67 ± 8 | 97 ± 19 | <0.001 |
| Systolic blood pressure, mmHg | 132 ± 17 | 137 ± 18 | 130 ± 17 | 0.266 |
| Diastolic blood pressure, mmHg | 76 ± 12 | 80 ± 13 | 75 ± 11 | 0.204 |
| Peripheral oxygen saturation, % | 94 ± 8 | 98 ± 1 | 92 ± 9 | 0.055 |
| Respiratory rate, per min | 20 ± 7 | 13 ± 2 | 22 ± 6 | <0.001 |
| WHO clinical severity score | ||||
| Hospitalized, no oxygen therapy | 7 (26%) | — | 7 (26%) | — |
| Oxygen by mask or nasal prongs | 12 (44%) | — | 12 (44%) | |
| Non-invasive ventilation | 2 (7%) | — | 2 (7%) | |
| Mechanical ventilation | 6 (22%) | — | 6 (22%) | |
| COVID-19 diagnosis | ||||
| PCR test | 27 (73%) | 0 (0%) | 27 (100%) | — |
| Nosocomial | 1 (3%) | 0 (0%) | 1 (4%) | — |
| Radiology, chest radiograph, or CT scan | ||||
| Typical of COVID-19 | 20 (80%) | — | 20 (80%) | — |
| Atypical of COVID-19 | 0 (0%) | — | 0 (0%) | |
| Unlikely | 0 (0%) | — | 0 (0%) | |
| Normal | 5 (20%) | — | 5 (20%) | |
| Acute COVID-19 therapy | ||||
| Oxygen | 20 (74%) | — | 20 (74%) | — |
| Steroid | 15 (56%) | — | 15 (56%) | — |
| Antiviral | 9 (33%) | — | 9 (33%) | — |
| Non-invasive respiratory support | 6 (22%) | — | 6 (22%) | — |
| Intensive care | 9 (33%) | — | 9 (33%) | — |
| Invasive ventilation | 5 (19%) | — | 5 (19%) | — |
| Intravenous inotrope | 3 (11%) | — | 3 (11%) | — |
| Cardiovascular history | ||||
| Smoking | ||||
| Never | 20 (54%) | 6 (60%) | 14 (52%) | 0.866 |
| Former | 14 (38%) | 3 (30%) | 11 (41%) | |
| Current | 3 (8%) | 1 (10%) | 2 (7%) | |
| Hypercholesterolaemia | 24 (65%) | 5 (50%) | 19 (70%) | 0.275 |
| Hypertension | 8 (22%) | 2 (20%) | 6 (22%) | 1.000 |
| Diabetes mellitus | 8 (22%) | 1 (10%) | 7 (26%) | 0.404 |
| Chronic kidney disease | 0 (0%) | 0 (0%) | 0 (0%) | 1.000 |
| CCS angina class | ||||
| Angina | 36 (97) | 10 (100%) | 26 (96%) | 1.000 |
| Myocardial infarction | 2 (5%) | 0 (0%) | 2 (7%) | 1.000 |
| Stroke or TIA | 2 (5%) | 0 (0%) | 2 (7%) | 1.000 |
| Peripheral vascular disease | 0 (0%) | 0 (0%) | 0 (0%) | 1.000 |
| Previous PCI | 2 (5%) | 0 (0%) | 2 (7%) | 1.000 |
| Cardiovascular disease and/or treatment | 14 (38%) | 3 (30%) | 11 (41%) | 0.710 |
| Risk scores | ||||
| ISARIC-4c in-hospital mortality risk, in % | 10.7 ± 7.5 | 5.4 ± 5.4 | 12.7 ± 7.2 | 0.006 |
| Q-Risk 3, 10-year cardiovascular risk, in % | 14.5 ± 9.6 | 14.3 ± 9.3 | 14.5 ± 9.9 | 0.961 |
| Charlson co-morbidity index | 1.8 ± 1.4 | 1.3 ± 1.1 | 2.0 ± 1.5 | 0.196 |
| Pre-existing maintenance medication | ||||
| Aspirin | 3 (8%) | 0 (0%) | 3 (11%) | 0.548 |
| Statin | 11 (30%) | 3 (30%) | 8 (30%) | 1.000 |
| Beta-blocker | 4 (11%) | 1 (10%) | 3 (11%) | 1.000 |
| Angiotensin converting enzyme inhibitor | 6 (16%) | 0 (0%) | 6 (22%) | 0.162 |
| Angiotensin receptor blocker | 1 (3%) | 0 (0%) | 1 (4%) | 1.000 |
| Oral anticoagulation | 0 (0%) | 0 (0%) | 0 (0%) | 1.000 |
| Laboratory results, index admission | ||||
| Initial haemoglobin, g/L | 144 ± 12 | 143 ± 13 | 145 ± 13 | 0.772 |
| Initial platelet count, 109/L | 236 ± 77 | 250 ± 60 | 231 ± 83 | 0.516 |
| Initial white cell count, 109/L | 7.53 ± 3.80 | 6.48 ± 1.83 | 7.91 ± 4.27 | 0.314 |
| Initial lymphocyte count, 109/L | 1.29 ± 0.64 | 1.91 ± 0.43 | 1.07 ± 0.55 | 0.001 |
| Peak D-dimer, ng/mL | 3931 ± 9732 | 195 ± 78 | 5052 ± 10 904 | 0.293 |
| Minimum eGFR, mL/min/1.73 m2 | 76.5 ± 30.9 | 107.0 ± — | 75.4 ± 30.9 | 0.325 |
| Acute kidney injury | 5 (20%) | — | 5 (20%) | — |
| Peak hs-troponin I, ng/L | 4.0 (4.0, 29.5) | 4.0 (4.0, 4.0) | 5.0 (4.0, 57.0) | 0.187 |
| Peak ferritin, μg/L | 213 (147, 1040) | 152 (97, 188) | 327 (200, 1505) | 0.018 |
| Peak C-reactive protein, mg/L | 72 (11, 170) | 2 (1, 5) | 110 (58, 186) | <0.001 |
| Peak HbA1c, mmol/mol | 46.1 ± 18.9 | 49.5 ± 35.5 | 45.1 ± 11.1 | 0.572 |
| Initial albumin, g/L | 35.2 ± 5.7 | 40.5 ± 4.0 | 33.2 ± 5.0 | 0.002 |
| Timelines | ||||
| Hospitalized | 25 (93%) | — | 25 (93%) | — |
| Duration of admission, days | 10 (4, 20) | — (—, —) | 10 (4, 20) | — |
| Symptom onset to the primary outcome, days | 69 (64, 74) | — (—, —) | 69 (64, 74) | — |
| Diagnosis to the primary outcome, days | 67 (62, 72) | — (—, —) | 67 (62, 72) | — |
Summaries are mean ± SD, median (IQR), or N (%). P-values from t-test, Wilcoxon–Mann–Whitney test, or Fisher's exact test. Abbreviations: SIMD, Scottish Index of Multiple Deprivation; PCR, polymerase chain reaction; CCS, Canadian Cardiovascular Society; TIA, transient ischaemic attack; PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft; HbA1c, glycated haemoglobin test.
aEnrolment—during acute COVID-19 admission for COVID-19 group, and at attendance for screening to participate as a non-COVID-19 control for the control group.