@article{KuchlerGuenthnerRibeiroetal.2023,
  author    = {Kuchler, Timon and G{\"u}nthner, Roman and Ribeiro, Andrea and Hausinger, Renate and Streese, Lukas and W{\"o}hnl, Anna and Kesseler, Veronika and Negele, Johanna and Assali, Tarek and Carbajo-Lozoya, Javier and Lech, Maciej and Adorjan, Kristina and Stubbe, Hans Christian and Hanssen, Henner and Kotliar, Konstantin and Haller, Berhard and Heemann, Uwe and Schmaderer, Christoph},
  title     = {Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation},
  volume    = {26},
  publisher = {Springer Nature},
  address   = {Dordrecht},
  doi       = {10.1007/s10456-023-09885-6},
  pages     = {547 -- 563},
  year      = {2023},
  abstract  = {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.},
  language  = {en}
}
@article{PresslerEsefeldScherretal.2010,
  author    = {Pressler, Axel and Esefeld, Katrin and Scherr, Johannes and Ali, Mohammad and Hanssen, Henner and Kotliar, Konstantin and Lanzl, Ines and Halle, Martin and Kaemmerer, Harald and Schmidt-Trucks{\"a}ss, Arno and Hager, Alfred},
  title     = {Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation},
  series = {The American Journal of Cardiology},
  volume    = {105},
  journal   = {The American Journal of Cardiology},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0002-9149},
  doi       = {10.1016/j.amjcard.2009.10.070},
  pages     = {740 -- 744},
  year      = {2010},
  abstract  = {Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5\%, first to third quartile 2.1\% to 4.5\% vs 3.6\%, first to third quartile 2.2\% to 4.3\%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.},
  language  = {en}
}