Numbers and phenotype of non-classical CD14^dimCD16⁺ monocytes are predictors of adverse clinical outcome in patients with coronary artery disease and severe SARS-CoV-2 infection

To elucidate the prognostic role of monocytes in the immune response of patients with coronary artery disease (CAD) at risk for life-threatening heart and lung injury as major complications of SARS-CoV-2 infection.

From February to April 2020, we prospectively studied a cohort of 96 participants comprising 47 consecutive patients with CAD and acute SARS-CoV-2 infection (CAD + SARS-CoV-2), 19 CAD patients without infections, and 30 healthy controls. Clinical assessment included blood sampling, echocardiography, and electrocardiography within 12 h of admission. Respiratory failure was stratified by the Horovitz Index (HI) as moderately/severely impaired when HI ≤200 mmHg. The clinical endpoint (EP) was defined as HI ≤200 mmHg with subsequent mechanical ventilation within a follow-up of 30 days. The numbers of CD14^dimCD16⁺ non-classical monocytes in peripheral blood were remarkably low in CAD + SARS-CoV-2 compared with CAD patients without infection and healthy controls (P < 0.0001). Moreover, these CD14^dimCD16 monocytes showed decreased expression of established markers of adhesion, migration, and T-cell activation (CD54, CD62L, CX3CR1, CD80, and HLA-DR). Decreased numbers of CD14^dimCD16⁺ monocytes were associated with the occurrence of EP. Kaplan–Meier curves illustrate that CAD + SARS-CoV-2 patients with numbers below the median of CD14^dimCD16⁺ monocytes (median 1443 cells/mL) reached EP significantly more often compared to patients with numbers above the median (log-rank 5.03, P = 0.025).

Decreased numbers of CD14^dimCD16⁺ monocytes are associated with rapidly progressive respiratory failure in CAD + SARS-CoV-2 patients. Intensified risk assessments comprising monocyte sub- and phenotypes may help to identify patients at risk for respiratory failure.