Microvascular Dysfunction in Patients with Critical Covid-19, a Pilot Study

Shock. 2021 Dec 1;56(6):964-968. doi: 10.1097/SHK.0000000000001803.


Background: Endothelial and microvascular dysfunction may be a key pathogenic feature of severe COVID-19. The aim of this study was to investigate endothelial-dependent and endothelial-independent skin microvascular reactivity in patients with critical COVID-19.

Methods: Twelve patients with COVID-19 treated with non-invasive or invasive mechanical ventilation were included in the study. We investigated skin microvascular reactivity on 2 separate days during hospitalization (study day 1 and 2) and at least 3 months after disease onset (study day 3). Twelve controls with no confirmed or suspected COVID-19 infection during 2020 were also examined. Skin perfusion was investigated through Laser Speckle Contrast Imaging before and after iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to determine the endothelial-dependent and the endothelial-independent vasodilation, respectively.

Results: Compared to controls, patients with critical COVID-19 had higher basal skin perfusion and reduced responses to endothelial-dependent (ACh, P = 0.002) and endothelial-independent (SNP, P = 0.01) vasodilator drugs on study day 1. In addition, the ACh/SNP ratio was significantly reduced in patients (0.50 ± 0.36 vs. 0.91 ± 0.49 in controls, P = 0.02). Three months after disease onset, surviving patients tended to have reduced ACh-mediated vasodilation compared to controls (P = 0.08).

Conclusions: This small-sized pilot study demonstrates that critical COVID-19 infection is associated with microvascular impairment and, in particular, a markedly reduced endothelial function. Our results also suggest that microvascular function may not be fully recovered 3 months after disease onset.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • COVID-19 / epidemiology*
  • COVID-19 / physiopathology
  • Comorbidity
  • Critical Illness / epidemiology*
  • Endothelium, Vascular / physiopathology*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Microcirculation / physiology*
  • Microvessels / physiopathology
  • Middle Aged
  • Pilot Projects
  • Prospective Studies
  • Regional Blood Flow / physiology*
  • SARS-CoV-2
  • Vasodilation / physiology*