Background: patients on maintenance hemodialysis (MHD) are at high risk of adverse clinical course of COVID-19. Study objective: analysis and evaluation of heart condition and risk factors of adverse clinical course of COVID-19 in patients on MHD. Materials and methods: 85 patients were included in retrospective observational hospital-based study in Moscow City Hospital 52 from 04.15 to 06.02.2020. The endpoints were results of hospitalization: discharge or lethal outcome. Several demographic, anamnestic, clinical and instrumental indicators were analyzed. Among them: gender, age, general and cardiovascular comorbidity (Charlson index, CCI), the type of vascular dialysis access, the etiology of ESKD, dialysis vintage, body mass index (BMI), cardiovascular events (CVE) in the course of hospital stay (myocardial infarction, MI, pulmonary embolism, PE, and others), ICU admission, mechanical ventilation (MV), the results of echocardiography and lung computed tomography (CT). Odds ratio (OR) was calculated and logistic regression with step-by-step algorithm was applied to assess risk factors of adverse outcomes of COVID-19 in cohort under study. Results: The mean age was 65±13 years (59%, males). Mortality in whole cohort was 43.5% (75%, in ICU patients, and 89% in patient on MV). The concomitant diseases were hypertension (92%), ischemic heart disease (54%), recent MI (19%), chronic heart failure (55%), permanent atrial fi brillation (20%) and diabetes (45%). Mean CCI was 6.6±2.4. Obesity was observed in 33% of cases. No statistical confi dence was found in CCI (6.3±2.4 points (survivors) vs 7.0±2.3 points, p>0.05), BMI (26.8±5.3 kg/m vs 27.1±5.8 kg/m , p>0.05). The total number of CVE - 20 (4 vs 16, p=0.019), MI - 10%, PE - 6%. No statistically signifi cant difference was found in LV myocardial mass index - average index 140±33 g/m (138±36 g/m vs 143±30 g/m2, p>0.05), LA volume index - median 35 (33; 40) ml/m2 - 35 (33; 40) ml/m vs 36 (35; 38) ml/m , p>0.05. In 35% systolic disfunction of right ventricle was observed with no difference between groups. The average index of left ventricle ejection fraction (LVEF) was 53±9% (54±6% vs 50±10%, p=0.019). The median of pulmonary artery systolic pressure - 40 mm Hg (30; 53) (38 (30; 52) mm Hg vs 42 mm (34; 53) Hg, p>0.05). The highest OR was calculated for following parameters: MV (OR=31.95% CI 18-121, p=0.0001), CVE (OR=8.3, 95% CI=2.5-2.8, p=0.0001), CCI ≥6 (OR=4.8, CI=1.6-11.2, p=0.002) and LVEF ≤45% (OR=3-8, 95%, CI=1.3-11,3, p=0.018). Regression logistic analysis demonstrated a strong relationship of lethal outcome with MV (OR=18.0) and CVE (OR=8.5), the moderate relationship with male gender (OR=2.1) and CCI (OR=1.25). Conclusion: the predictors of adverse outcome of COVID-19 in patients on MHD are the need for MV, CVE, CCI ≥6, decline of LVEF ≤45%, male gender. 2 2 2 2 2 2