ABSTRACT
Introduction: The global pandemic with COVID-19 threatened hemodialysis (HD) patients as susceptible category with high risk for lethal outcome. The aim of the study was to determine the prevalence and risk factors for mortality in HD patients with confirmed COVID-19 and the effectiveness of vaccination against COVID-19. Method(s): The prospective observational multicentric cohort study included all HD patients over a period since March 2020 to March 2022. The outcome of patients with confirmed COVID-19 regarding infection timing and vaccination status was evaluated. The examined clinical parameters were: age, sex, HD duration, neutralizing S-antibody titer against COVID-19, serum albumin, comorbidities and hospital admission. Statistical analysis was performed by SPSS, continued variables with analysis of variance and categorical variables with Chi-square test and logistic regression, and survival analysis by Kaplan-Meyer test. Result(s): Over the observed period of total 629 HD patients 318 patients had COVID-19 infection (COVID-19 group) and 311 patients had no COVID-19 (Noninfected group). Vaccine coverage with 2 and 3 doses were significantly higher in the Noninfected group compared to COVID-19 group. In the COVID-19 group 214 patients had COVID-19 (4 patients reinfection) before vaccination (Prevaccination COVID-19 subgroup) and 104 patients had COVID-19 (15 patients reinfection) after vaccination (Postvaccination COVID-19 subgroup). The patients vaccinated with 3 doses had the lowest infection rate of 14,5%. Over the observed period overall 76 patients or 24% with COVID-19 deceased. The hospitalization rate and mortality were higher in the Prevaccination COVID-19 subgroup (51,9% and 26,2%) compared to Postvaccination COVID-19 subgroup (37,5% and 19,2%), but statistically significant only for hospitalization rate. In the COVID-19 group clinical parameters showed that deceased patients compared with survived patients had statistically significant higher age and lower s-albumin. Statistically significant predictive risk factors for lethal outcome were non-vaccination (HR=18,3), age over 80 years (HR=5,1) and cardiomyopathy (HR=2,5). Regarding S-antibody titer against COVID-19 after the second vaccine dose statistically significant higher titer had the Prevaccination COVID-19 subgroup and the Postvaccination COVID-19 Reinfection subgroup compared to Noninfected group and Postvaccination COVID-19 subgroup, and the Noninfected group compared to Postvaccination COVID-19 subgroup. After the third vaccine dose the Prevaccination COVID-19 subgroup had statistically significant higher titer compared to Noninfected group. In the Postvaccination COVID-19 subgroup after 2 vaccine doses deceased patients had statistically significant lower S-antibody titer compared with survived patients. The cumulative survival in the Postvaccination COVID-19 subgroup was 28,4% after the second vaccine dose and 100% after the third vaccine dose, that was statistically significant. Conclusion(s): Our study showed that mortality is high in HD patients with COVID-19 and amounts 24%. The mortality was associated with advanced age, low level of s-albumin, cardiomyopathy and low S-antibody titer against COVID-19. The vaccination protection against COVID-19 was the highest in patients after the third vaccine dose in whom the lowest infection rate and no lethal outcome after infection with COVID-19 was observed. No conflict of interestCopyright © 2023
ABSTRACT
BACKGROUND AND AIMS: The global pandemic with SARS-CoV-2 virus and Covid-19 threatened hemodialysis patients as vulnerable category with high risk for fatal outcome. The aim of the study was to determine the prevalence and risk factors for mortality in hemodialysis (HD) patients with confirmed Covid-19. METHOD: This study was retrospective, multicentric, and included all HD patients with positive PCR test for SARS-CoV-2 during the period of 10 months from March 1-December 31/2020. The outcome of patients with positive PCR test for SARS CoV-2 was evaluated. The following clinical parameters were compared in two groups of patients (the deceased and alive): age, sex, hemodialysis vintage, type of vascular access, BMI, Hemoglobin, WBC, Platelets, CRP, LDH, D-dimer, s-albumin, radiological findings, smoking abuse, therapy with ACE and ARBs, presence of symptoms and comorbidities: hypertension (HTA), diabetes mellitus (DM), coronary artery disease (CAD), chronic pulmonary disease (CPD), dyslipidemia, atrial fibrillation (AFF), malignancy, treatment in hospital and intensive care unit (ICU) with oxygen support and mechanical ventilation, and anticoagulant therapy. Statistical analysis was performed by SPSS, continued variables with ANOVA and categorical variables with Pearson Chi-square test and logistic regression. RESULTS: Of total 631 hemodialysis patients during the period of 10 months 162 patients (113 Mand 49 F) or 25,67% were with positive PCR test for SARS-CoV-2, they have had mean age 62,47±13,14 years and HD vintage 71,93±68,01 months. During the observed period 38 patients with Covid-19 (25 Mand 13 F) deceased, that represents mortality of 23,45%, 8 patients deceased at home and 30 patients in hospital. The mortality in patients with age range 18-49 years was 8%, with 50-59 years 18,9%, with 60-69 years 22,2%, with 70-79 years 31,2% and in patients with ≥ 80 years was 50%. Clinical parameters showed that the deceased patients compared with alive patients have had statistically significant higher age (67,7±10,57 vs 60,85±13,46 years;p=0.004), biochemical findings WBC (9,13±4,07 vs 6,45±3,0;p<0.001), LDH (394±4,07 vs 294±143;p=0.032), D-dimer (3699±4,07 vs 2025±2628;p=0.041), lower s-albumin (25,03±4,0 vs 34,57±6,89;p<0.001), and less hospital days (9,87±12,15 vs 16,24±14,31;p=0.04). Regarding comorbidities the mortality in the deceased patients was significantly higher in patients with chronic pulmonary disease (CPD) in comparison to patients without CPD (56,3% vs 19,9%;p=0.001), and in patients with malignancy in comparison to patients without malignancy (57,1% vs 21,9%;p=0.032). The mortality in hospitalized patients was significantly higher in comparison to treated patients at home (25,8% vs 10,5%;p<0.001) and was significantly higher in patients treated in ICU in comparison to patients treated at hospital (40,7% vs 25%;p<0.001). By logistic regression model it was determined that presence of chronic pulmonary disease (HR=6,178;p=0.008), ICU treatment (HR=5,311;p=0.01) and malignancy (HR=16,766;p=0.01) were the most predictive risk factors for mortality. CONCLUSION: Our study showed that mortality is high in HD patients with Covid-19 and amounts 23,45%, which is in accordance with other larger studies of ERACODA and ERA-EDTA registry regarding mortality of hemodialysis patients with Covid-19 (25% vs 20%). The mortality in HD patients with Covid-19 was associated with advanced age, high level of WBC, LDH and D-dimer, and low level of s-albumin. In contrast to general population, no association with gender, diabetes and cardiovascular disease, but significant association of mortality with presence of chronic pulmonary disease, malignancy, hospital and ICU treatment was found.