TY  - JOUR
A1  - Kuchler, Timon
A1  - Günthner, Roman
A1  - Ribeiro, Andrea
A1  - Hausinger, Renate
A1  - Streese, Lukas
A1  - Wöhnl, Anna
A1  - Kesseler, Veronika
A1  - Negele, Johanna
A1  - Assali, Tarek
A1  - Carbajo-Lozoya, Javier
A1  - Lech, Maciej
A1  - Adorjan, Kristina
A1  - Stubbe, Hans Christian
A1  - Hanssen, Henner
A1  - Kotliar, Konstantin
A1  - Haller, Berhard
A1  - Heemann, Uwe
A1  - Schmaderer, Christoph
T1  - Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation
N2  - Background
Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians.

Methods
In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204).

Measurements and main results
PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42% ± 1.77% vs. 4.64% ± 2.59%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5–190.2] vs. 189.1 [179.4–197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8–0.9] vs. 0.88 [0.8–0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = − 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters.

Conclusion
Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.
KW  - Endothelial dysfunction
KW  - Long COVID
KW  - Post-COVID-19 syndrome
KW  - retinal microvasculature
Y1  - 2023
U6  - http://dx.doi.org/10.1007/s10456-023-09885-6
N1  - Corresponding author: Christoph Schmaderer
VL  - 26
SP  - 547
EP  - 563
PB  - Springer Nature
CY  - Dordrecht
ER  -