FACTORS AFFECTING COVID-19 OUTCOMES IN PATIENTS WITH HEMATOLOGICAL MALIGNANCIES

Abstract

Background. Patients with hematological malignancies (HM) are considered to have a high risk of developing severe and life-threatening infections including COVID-19 because of immune deficiency and immunosuppressive treatments. Al¬though the COVID pandemic spread worldwide, morbidity and mortality data varied from country to country. A more accurate identification of risk factors would allow the improvement of the clinical management of HM patients. Aim. This study aimed to determine real-life data - the mortality rate, clinical outcomes, and risk factors affecting mortality in patients with HM and COVID-19 at the Riga East University Hospital (REUH) in Latvia. Materials and Methods. In this retrospective non-interventional cohort study, we included adult patients treated in REUH with ongoing HM and laboratory-confirmed COVID-19 observed between December 1st, 2020, and March 31st, 2023. All data were analyzed using descriptive statistics, binary logistic regression, univariable Cox regression model, and other methods. Results. We registered 156 patients with 11 different HMs. Multiple myeloma, non-Hodgkin lymphoma, and acute myeloid leu¬kemia were the most common HM. COVID-19 mortality rate was 19.9% (31/156). Factors increasing the risk of death included the severity of COVID-19 (p < 0.001), the accession of bacterial infection (p < 0.001), longer hospital stay (p = 0.037), absolute neutrophil count (ANC) ≤ 0.5 × 109/mm3 (p = 0.014), fever (p = 0.039), and acute myeloid leukemia (p = 0.002). We also confirmed that the mortality in the third pandemic wave was significantly lower than in the second wave (p = 0.002). Although vaccination seemed to be a risk-mitigating factor (58.8% [10/17] of those who died from COVID-19 were not vaccinated), no statistically important correlation was found (p = 0.690). Conclusion. This survey confirmed that the COVID-19 mortality rate was higher in patients with HM (19.9% [31/156]) than in the population. ANC, severity of COVID-19, accession of bacterial infection, hospital stay, fever, and acute myeloid leukemia were the factors that increased mortality in HM patients.