Background Patients with hematological malignancies (HM) are at high risk of mortality from SARS-CoV-2 disease 2019 (COVID-19). A better understanding of risk factors for adverse outcomes may improve clinical management in these patients. We therefore studied baseline characteristics of HM patients developing COVID-19 and analyzed predictors of mortality. Methods The survey was supported by the Scientific Working Group Infection in Hematology of the European Hematology Association (EHA). Eligible for the analysis were adult patients with HM and laboratory-confirmed COVID-19 observed between March and December 2020. Results The study sample includes 3801 cases, represented by lymphoproliferative (mainly non-Hodgkin lymphoma n = 1084, myeloma n = 684 and chronic lymphoid leukemia n = 474) and myeloproliferative malignancies (mainly acute myeloid leukemia n = 497 and myelodysplastic syndromes n = 279). Severe/critical COVID-19 was observed in 63.8% of patients (n = 2425). Overall, 2778 (73.1%) of the patients were hospitalized, 689 (18.1%) of whom were admitted to intensive care units (ICUs). Overall, 1185 patients (31.2%) died. The primary cause of death was COVID-19 in 688 patients (58.1%), HM in 173 patients (14.6%), and a combination of both COVID-19 and progressing HM in 155 patients (13.1%). Highest mortality was observed in acute myeloid leukemia (199/497, 40%) and myelodysplastic syndromes (118/279, 42.3%). The mortality rate significantly decreased between the first COVID-19 wave (March–May 2020) and the second wave (October–December 2020) (581/1427, 40.7% vs. 439/1773, 24.8%, p value < 0.0001). In the multivariable analysis, age, active malignancy, chronic cardiac disease, liver disease, renal impairment, smoking history, and ICU stay correlated with mortality. Acute myeloid leukemia was a higher mortality risk than lymphoproliferative diseases. Conclusions This survey confirms that COVID-19 patients with HM are at high risk of lethal complications. However, improved COVID-19 prevention has reduced mortality despite an increase in the number of reported cases.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused high mortality in patients with hematological malignancies (HM). 1 The newly emerged omicron variants of SARS-CoV-2 harbor multiple novel spike protein mutations that raise concerns about vaccine efficiency and antiviral efficacy of the available therapeutic monoclonal antibodies. 2 The first published clinical data in immunocompetent patients have found that infection with omicron variants is associated with reduced vaccine efficiency compared to the delta variants, but decreased hospital admission and mortality. 3,4 Preliminary, prepublished, data from a large case-control study have shown that the vaccine effect against omicron in immunocompromised patients, including HM patients, is even more reduced, but data regarding clinical outcomes are lacking. 5 The aim of this study was to describe risk factors, antiviral treatment and outcomes of SARS-CoV-2 omicron variant infection in 593 HM patients included in the EPICOVIDEHA registry.EPICOVIDEHA is an international open web-based registry for patients with HM infected with SARS-CoV-2. 1,6 Both hospitalized and nonhospitalized patients are eligible for inclusion. The questionnaire includes data on the HM, SARS-CoV-2 vaccination status, risk factors for severe COVID-19 infection, SARS-CoV-2 virus variant, antiviral treatment, and outcomes including mortality (eFigure 1 and eTable 4).