Summary Bleeding and thrombosis are major complications in patients supported with extracorporeal membrane oxygenation (ECMO). In this multicentre observational study of 152 consecutive patients (≥18 years) with severe COVID‐19 supported by veno‐venous (VV) ECMO in four UK commissioned centres during the first wave of the COVID‐19 pandemic (1 March to 31 May 2020), we assessed the incidence of major bleeding and thrombosis and their association with 180‐day mortality. Median age (range) was 47 years (23–65) and 75% were male. Overall, the 180‐day survival was 70·4% (107/152). The rate of major bleeding was 30·9% (47/152), of which intracranial bleeding (ICH) was 34% (16/47). There were 96 thrombotic events (63·1%) consisting of venous 44·7% [68/152 of which 66·2% were pulmonary embolism (PE)], arterial 18·6% (13/152) and ECMO circuit thrombosis 9·9% (15/152). In multivariate analysis, only raised lactate dehydrogenase (LDH) at the initiation of VV ECMO was associated with an increased risk of thrombosis [hazard ratio (HR) 1·92, 95% CI 1·21‐3·03]. Major bleeding and ICH were associated with 3·87‐fold (95% CI 2·10–7·23) and 5·97‐fold [95% confidence interval (CI) 2·36–15·04] increased risk of mortality and PE with a 2·00‐fold (95% CI1·09–3·56) risk of mortality. This highlights the difficult balancing act often encountered when managing coagulopathy in COVID‐19 patients supported with ECMO.

Summary Coagulation dysfunction and thrombosis are major complications in patients with coronavirus disease 2019 (COVID‐19). Patients on oral anticoagulants (OAC) prior to diagnosis of COVID‐19 may therefore have better outcomes. In this multicentre observational study of 5 883 patients (≥18 years) admitted to 26 UK hospitals between 1 April 2020 and 31 July 2020, overall mortality was 29·2%. Incidences of thrombosis, major bleeding (MB) and multiorgan failure (MOF) were 5·4%, 1·7% and 3·3% respectively. The presence of thrombosis, MB, or MOF was associated with a 1·8, 4·5 or 5·9‐fold increased risk of dying, respectively. Of the 5 883 patients studied, 83·6% (n = 4 920) were not on OAC and 16·4% (n = 963) were taking OAC at the time of admission. There was no difference in mortality between patients on OAC vs no OAC prior to admission when compared in an adjusted multivariate analysis [hazard ratio (HR) 1·05, 95% confidence interval (CI) 0·93–1·19; P = 0·15] or in an adjusted propensity score analysis (HR 0·92 95% CI 0·58–1·450; P = 0·18). In multivariate and adjusted propensity score analyses, the only significant association of no anticoagulation prior to diagnosis of COVID‐19 was admission to the Intensive‐Care Unit (ICU) (HR 1·98, 95% CI 1·37–2·85). Thrombosis, MB, and MOF were associated with higher mortality. Our results indicate that patients may have benefit from prior OAC use, especially reduced admission to ICU, without any increase in bleeding.

The impact of COVID-19 infection on pregnant women remains relatively unknown but the physiological changes of pregnancy and hypercoagulability of COVID-19 may further increase thrombotic risk. In this retrospective multicentre observational study, we report clinical characteristics and outcomes in 36 pregnant women requiring hospitalisation for COVID-19 compared to a propensity-matched cohort of non-pregnant women. Pregnant women had a lower haemoglobin and higher lymphocyte counts but no differences in other haematological or biochemical parameters on admission compared to non-pregnant women. There was no significant difference in the duration of hospitalisation; median two days (1-77) for pregnant versus eight days (1-49) for non-pregnant women. A higher proportion of nonpregnant women required mechanical ventilation [11/36 (31%) vs 3/36 (8%), P = 0Á03] and received thromboprophylaxis with low-molecular-weight heparin (LMWH) within 24 h of admission [25/36 (69%) vs 15 /36(42%), P = 0Á03] compared to pregnant women. One pregnant woman required extracorporeal membrane oxygenation. The rate of thrombosis was similar in both groups (one in each group). No women developed major bleeding or died. Data suggest that although non-pregnant women had a severe clinical course, overall outcomes were not different between women with or without pregnancy. The use of thromboprophylaxis was inconsistent, demonstrating a need for establishing evidence-based guidance for COVID-19 during pregnancy.

Objective To establish the demographic characteristics, laboratory findings and clinical outcomes in patients with autoimmune disease (AD) in comparison to a propensity matched cohort of patients without AD admitted with COVID-19 to hospitals in the UK. Methods This is a multicentre observational study across 26 NHS Trusts. Data were collected both retrospectively and prospectively using a pre-designed standardised case record form. Adult patients (≥18 years) admitted between 1st of April 2020 and 31 July 2020 were included. Results Overall, 6288 patients were included to the study. Of these, 394 patients had AD prior to admission with COVID-19. Of 394 patients, 80 patients with systemic lupus erythematosus, rheumatoid arthritis or antiphospholipid syndrome were classified as severe rheumatologic AD. A higher proportion of those with AD had anaemia: 240(60.91%) vs 206(52.28%), p= 0.015, raised LDH 150(38.08%) vs 43(10.92%), p< 0.001 and raised creatinine 122(30.96%) vs 86(21.83%), p= 0.01 respectively. A significantly higher proportion of patients with severe rheumatologic AD had raised CRP : 77(96.25%) vs 70(87.5%), p= 0.044 and LDH 20(25%) vs 6(7.5%), p= 0.021. Patients with severe rheumatologic AD had significantly higher mortality [32/80(40%)] compared with propensity matched cohort of patients without AD [20/80(25%)], p= 0.043. However, there was no difference in 180-day mortality between propensity matched cohorts of patients with or without AD in general, p= 0.47. Conclusions Patients with severe rheumatologic AD had significantly higher mortality. Anaemia, renal impairment and raised LDH were more frequent in patients with any AD whilst raised CRP and LDH were more frequent in patients with severe rheumatologic AD both of which have been shown to associate with increased mortality in patients with COVID-19.