Detailed videocapillaroscopic microvascular changes detectable in adult COVID-19 survivors

COVID-19 is a multisystem disease that causes endothelial dysfunction and organ damage. Aim of the study was to evaluate the microvascular status in COVID-19 survivors with past different disease severity, in comparison with age and sex-matched primary Raynaud's phenomenon (PRP) patients and control subjects (CNT), including possible effects of concomitant therapies.

Sixty-one COVID-19 survivors (mean age 58 ± 13 years, mean days from disease onset 126 ± 53 and mean days from recovery 104 ± 53), thirty-one PRP patients (mean age 59 ± 15 years, mean disease duration 11 ± 10 years) and thirty CNT (mean age 58 ± 13 years) underwent nailfold videocapillaroscopy (NVC) examination. The following capillaroscopic parameters were searched and scored (0-3): dilated capillaries, giant capillaries, isolated microhemorrhages, capillary ramifications (angiogenesis) and capillary number, including absolute capillary number per linear millimeter at the nailfold bed.

The mean nailfold capillary number per linear millimeter was significantly lower in COVID-19 survivors when compared with PRP patients and CNT (univariate and multivariate analysis p < 0.001). On the contrary, COVID-19 survivors showed significantly less isolated microhemorrhages than PRP patients and CNT (univariate and multivariate analysis, p = 0.005 and p = 0.012, respectively). No statistically significant difference was observed between COVID-19 survivors and control groups concerning the frequency of dilated capillaries and capillary ramifications. COVID-19 selective therapies showed a promising trend on preserving capillary loss and deserving further investigations.

SARS-CoV-2 seems to mainly induce a significant loss of capillaries in COVID-19 survivors at detailed NVC analysis in comparison to controls. The presence of a significant reduced score for isolated microhaemorrhages in COVID-19 survivors deserves further analysis.