Determinants of the protective effect of glucocorticoids on mortality in hospitalized patients with COVID-19: Insights from the Cardio-COVID-Italy multicenter study

Background: Glucocorticoid therapy has emerged as an effective therapeutic option in hospitalized patients with coronavirus disease 2019 (COVID-19). Our aim was to focus on the impact of relevant clinical and laboratory factors on the protective effect of glucocorticoids on mortality. Methods: We performed a sub-analysis of the multicenter Cardio-COVID-Italy registry, enrolling consecutive patients with COVID-19 admitted to 13 Italian cardiology units between March 1st, 2020, and April 9th, 2020. The primary endpoint was in-hospital mortality. Results: A total of 706 COVID-19 patients were included (n = 349 treated with glucocorticoids, n = 357 not treated with glucocorticoids). After adjustment for relevant covariates, use of glucocorticoids was associated with a lower risk of in-hospital mortality (adjusted HR 0.44, 95% CI 0.26-0.72, p = 0.001). A significant interaction was observed between the protective effect of glucocorticoids on mortality and PaO2/FiO2 ratio on admission (p = 0.042), oxygen saturation on admission (p = 0.017), and peak CRP (0.023). Such protective effect of glucocorticoids was mainly observed in patients with lower PaO2/FiO2 ratio (<300), lower oxygen saturation (<90%), and higher CRP (>100 mg/L). Conclusions: The protective effects of glucocorticoids on mortality in COVID-19 was more evident among patients of worse respiratory parameters and higher systemic inflammation.