P1537: mortality and burden of post-covid-19 syndrome have reduced with time across sars-cov-2 variants in haematology patients

Topic: 30. Infections in hematology (incl. supportive care/therapy) Background: It was recognised early in the SARS-CoV-2 (COVID-19) pandemic that patients with haematological disorders were amongst the highest risk of death. Furthermore, a high proportion of patients surviving initial infection displayed ongoing symptoms beyond 12 weeks (post-COVID-19 syndrome). As such, haematology patients were encouraged during early waves to reduce the risk of contracting the virus by shielding, and later were prioritised for vaccination. We have found that a significant proportion of these patients have continued to reduce their interactions with others, potentially impairing their social, psychological and occupational well-being. As successive COVID-19 variants have arisen, it is important to understand how post-infection outcomes have changed in haematology patients in order to advise and guide patients and policy. Aims: Since the start of the pandemic, we setup a dedicated single-centre post-COVID-19 clinic, in which we sought to understand the clinical course following COVID-19 infection in haematology patients. Methods: All haematology patients contracting COVID-19 from 15th March 2020 to 10th March 2022 at a single centre were identified and those surviving 12 weeks after infection were invited to a dedicated telephone clinic, in which they were interviewed by a consultant haematologist, to identify the extent to which they have recovered from their infection. Results: In total, 128 patients were identified, and telephone interviews were conducted for 94 of 95 survivors. 90-day mortality attributed to COVID-19 (Figure 1A) has fallen sequentially from 42% (Original and Alpha strains) to 9% (Delta) and to 2% (Omicron). Rates of post-COVID-19 syndrome (Figure 1B) have fallen from 46% (17/37 patients) with either Original or Alpha variants to 35% (7/20 patients) with Delta, to 14% (5/37 patients) with the Omicron variant. The most common persistent symptoms were fatigue, shortness of breath, cough, and mood disturbance, all of which were less prevalent in the Omicron group, when compared with previous strains. We analysed factors from initial COVID-19 infection that affected risk of post-COVID-19 syndrome (Figure 1C). There was an increased risk in those who, at initial infection, had shortness of breath [OR: 11.5 (3.8-34.9)], required hospitalisation [OR: 8.4 (3.1-22.9)], or had an oxygen requirement [OR: 23.6 (6.7-83.5)], suggesting that more severe infection was associated with greater persistence of symptoms beyond 12 weeks. Infection in patients with Omicron (compared to Original, Alpha or Delta) variants had a lower risk of post-COVID-19 syndrome [OR: 0.21 (0.07-0.63)].Summary/Conclusion: These data support reduced mortality and post-COVID-19 sequelae with time, suggesting Omicron infection is a self-limiting illness for the majority of haematology patients. Nevertheless, many patients continue to exercise a great deal of caution due to the perceived threat from the virus. Such prolonged self-imposed social isolation may have negative effects on psychological and physical health, as well as restricting occupational activities. Our data could aid clinicians to communicate risk and to help our haematology patients to make informed choices about whether to ease their self-isolation. Keywords: COVID-19, Hematological malignancy, Mortality, Long-term follow-up