Detection of SARS-CoV-2 RNA in serum is associated with increased mortality risk in hospitalized COVID-19 patients.

COVID-19 has overloaded national health services worldwide. Thus, early identification of patients at risk of poor outcomes is critical. Our objective was to analyse SARS-CoV-2 RNA detection in serum as a severity biomarker in COVID-19. Retrospective observational study including 193 patients admitted for COVID-19. Detection of SARS-CoV-2 RNA in serum (viremia) was performed with samples collected at 48-72 h of admission by two techniques from Roche and Thermo Fischer Scientific (TFS). Main outcome variables were mortality and need for ICU admission during hospitalization for COVID-19. Viremia was detected in 50-60% of patients depending on technique. The correlation of Ct in serum between both techniques was good (intraclass correlation coefficient: 0.612; p < 0.001). Patients with viremia were older (p = 0.006), had poorer baseline oxygenation (PaO2/FiO2; p < 0.001), more severe lymphopenia (p < 0.001) and higher LDH (p < 0.001), IL-6 (p = 0.021), C-reactive protein (CRP; p = 0.022) and procalcitonin (p = 0.002) serum levels. We defined "relevant viremia" when detection Ct was < 34 with Roche and < 31 for TFS. These thresholds had 95% sensitivity and 35% specificity. Relevant viremia predicted death during hospitalization (OR 9.2 [3.8-22.6] for Roche, OR 10.3 [3.6-29.3] for TFS; p < 0.001). Cox regression models, adjusted by age, sex and Charlson index, identified increased LDH serum levels and relevant viremia (HR = 9.87 [4.13-23.57] for TFS viremia and HR = 7.09 [3.3-14.82] for Roche viremia) as the best markers to predict mortality. Viremia assessment at admission is the most useful biomarker for predicting mortality in COVID-19 patients. Viremia is highly reproducible with two different techniques (TFS and Roche), has a good consistency with other severity biomarkers for COVID-19 and better predictive accuracy.

IL-6 serum levels predict severity and response to tocilizumab in COVID-19: An observational study.

BACKGROUND: Patients with coronavirus disaese 2019 (COVID-19) can develop a cytokine release syndrome that eventually leads to acute respiratory distress syndrome requiring invasive mechanical ventilation (IMV). Because IL-6 is a relevant cytokine in acute respiratory distress syndrome, the blockade of its receptor with tocilizumab (TCZ) could reduce mortality and/or morbidity in severe COVID-19. OBJECTIVE: We sought to determine whether baseline IL-6 serum levels can predict the need for IMV and the response to TCZ. METHODS: A retrospective observational study was performed in hospitalized patients diagnosed with COVID-19. Clinical information and laboratory findings, including IL-6 levels, were collected approximately 3 and 9 days after admission to be matched with preadministration and postadministration of TCZ. Multivariable logistic and linear regressions and survival analysis were performed depending on outcomes: need for IMV, evolution of arterial oxygen tension/fraction of inspired oxygen ratio, or mortality. RESULTS: One hundred forty-six patients were studied, predominantly males (66%); median age was 63 years. Forty-four patients (30%) required IMV, and 58 patients (40%) received treatment with TCZ. IL-6 levels greater than 30 pg/mL was the best predictor for IMV (odds ratio, 7.1; P < .001). Early administration of TCZ was associated with improvement in oxygenation (arterial oxygen tension/fraction of inspired oxygen ratio) in patients with high IL-6 (P = .048). Patients with high IL-6 not treated with TCZ showed high mortality (hazard ratio, 4.6; P = .003), as well as those with low IL-6 treated with TCZ (hazard ratio, 3.6; P = .016). No relevant serious adverse events were observed in TCZ-treated patients. CONCLUSIONS: Baseline IL-6 greater than 30 pg/mL predicts IMV requirement in patients with COVID-19 and contributes to establish an adequate indication for TCZ administration.

Comparison between inferior vena cava ultrasound, lung ultrasound, bioelectric impedance analysis, and natriuretic peptides in chronic heart failure.

BACKGROUND: Heart failure (HF) is an important healthcare problem. Knowing volume status in outpatients with chronic HF to adjust treatment and to avoid decompensations is a challenge. The aim of this study is comparing the usefulness of inferior vena cava (IVC) ultrasound, lung ultrasound, bioelectrical impedance analysis (BIA), and natriuretic peptides in the follow-up of outpatients with chronic HF. METHODS: This was a prospective cohort study. Ninety-nine patients with chronic HF were included consecutively as they attended scheduled medical visits. The different techniques were performed on the day of the clinic visit, and the result was hidden from the patients and the responsible medical team. Follow-up time was 1 year. Outcome events checked were a combination of death or hospitalization, due to HF. RESULTS: Thirty-six patients (36.4%) died or were hospitalized for HF. They had a significantly lower IVC collapse, and a greater number of lung B-lines and higher NTproBNP levels compared to patients who remained stable. There were no differences in the BIA parameters. After multivariable analysis, cut-off points of IVC collapse <30%, number of pulmonary B lines greater than 5, and NTproBNP levels greater than 2000 pg/ml were associated with increased risk of HF death or admission. NTproBNP had the best area under the curve. CONCLUSION: Evaluation of congestion in outpatients with chronic HF may be based on NTproBNP, IVC ultrasound, or lung ultrasound; they are useful in identifying patients at high risk of hospitalization or death due to HF.

Usefulness of inferior vena cava ultrasonography in outpatients with chronic heart failure.

BACKGROUND: Inferior vena cava (IVC) ultrasonography has been used for the diagnosis and prognosis of acute heart failure (HF). Its usefulness in chronic HF is less known. HYPOTHESIS: IVC ultrasonography is a useful tool in the care of patients with chronic HF. METHODS: For this prospective cohort study, 95 patients with chronic HF were included consecutively as they attended scheduled medical visits. Ultrasound was done with a 5-MHz convex probe device, calculating IVC collapse index (IVCCI). Follow-up time was 1 year. Outcome events were worsening HF, hospital admission for HF, HF mortality, and all-cause mortality. RESULTS: Worsening HF occurred in 70.9% of patients with IVCCI <30% and 39.1% of patients with IVCCI >50%, with a hazard ratio (HR) of 2.8 (95% CI: 1.3-6.2) adjusted by multivariable analysis. Regarding hospitalization, 45.3% of patients with IVCCI <30% required admission, compared with 5.9% of patients with IVCCI >50%; the adjusted HR was 13.9 (95% CI: 1.7-113.0). Mortality was higher in the IVCCI <30% group, with 25.7% all-cause mortality and 18.6% HF mortality, whereas in the IVCCI >50% group these values were 13% and 4.7%, respectively. However, these differences did not reach statistical significance. ROC analysis was performed and the AUC for IVCCI was not higher than that for NTproBNP for any of the outcomes studied. CONCLUSIONS: IVC ultrasonography is a useful tool in follow-up of patients with chronic HF, allowing identification of patients at high risk of worsening and hospitalization. However, its usefulness is not higher than that of NTproBNP.