Estimated plasma volume status is an independent predictor for in-hospital mortality in COVID-19 patients with hypoxemic respiratory failure and heart failure

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Heart failure and hypoxemic respiratory failure were the leading causes for hospital admission and death in COVID-19 patients. Frequently, it is challenging to assess the plasma volume status in limited resource settings especially in times of COVID-19 pandemics. Thus, a practical and simple evaluation of congestion status is of importance to guide early management and risk stratification. Estimated plasma volume status (ePVS) has been associated with mortality in heart failure population. However, no study investigated the association between ePVS and prognosis in COVID-19 patients with hypoxemic respiratory failure and heart failure. Purpose To study the association between ePVS and in-hospital mortality in COVID-19 patients with hypoxemic respiratory failure and heart failure. We hypothesized that higher ePVS level which reflected a congested status could worsen the prognosis in severe COVID-19 patients with hypoxemic respiratory failure and heart failure. Methods We included severe COVID-19 subjects with hypoxemic respiratory failure and heart failure using our institution COVID-19 registry. Sample size was calculated using comparing two means hypothesis testing accordingly. The calculation of ePVS was performed using simple Duarte Formula; (100-hematocrit)/hemoglobin, which were taken at the time of admission. A logistic regression model was used to demonstrate the association between ePVS levels and in-hospital mortality. ROC curve analysis was used to assess the discrimination of ePVS for predicting in-hospital mortality. Results We enrolled 53 eligible subjects with an average age of 61 ± 10.3 years old with predominant male (69.8%). Thirty five patients died in hospital with the prevalence of in-hospital mortality was 66%. The ROC curve indicated that ePVS has acceptable discrimination for predicting in-hospital mortality. The AUC value was found to be 0.665 and ePVS value cut off was 4.5 ml/g with sensitivity of 77.8% and specificity of 65.7%. In the unadjusted model, high-level of ePVS (> 4.5 ml/g) was associated with higher OR (6.7; 95% CI 1.8–24.9; P 0.003) compared with low-level of ePVS (≤ 4.5 ml/g).After adjusted the vital signs data, laboratory and echocardiogram data, and treatment, high-level of ePVS was independently associated with increased OR of in-hospital mortality, 21.6 (95% CI 2.6–177.9; P < 0.004). Conclusions This study demonstrated that high ePVS level, calculated with a simple Duarte Formula, was associated with higher in-hospital mortality in COVID-19 patients with hypoxemic respiratory failure and heart failure. Thus, this finding could help physicians for a better risk stratification in managing COVID-19 patients in limited resource settings or in early phase of hospitalization.