Endothelial function one year after COVID-19: unexpected results

Endothelin-1 is an endothelial dysfunction marker increased during COVID-19 associated pneumonia and in early post-COVID-19 period. However, it is not clear whether ET-1 decrease over time, in late post-COVID-19 period. <bold>Aim:</bold> – to determine the relation between the improvement of clinical and functional status of patients after COVID-19-pneumonia and the dynamics of ET-1 serum level. <bold>Materials and methods:</bold> Main group – 15 pts after COVID-19 associated pneumonia (age – 53,0 (44,0; 61,5), men – 9 (60,0 %)). They were investigated twice: visit 1 – at 60,0 (55,0; 67,5) day from COVID-19 onset (early post-COVID-19 period), visit 2 – at 330,0 (275,0; 365,0) day from COVID-19 onset (late post-COVID-19 period). Methods included 6-minute walking test (6MWT) and diffusion lung ability measurement (DLCO). ELISA-kit were used in order to determine serum level of ET-1. Non-parametrical statistics was used. <bold>Results:</bold> 2 (13,3 %) pts had moderate course of COVID-19, 6 (40,0 %) pts – severe, 7 (46,7 %) pts – critical. ET-1 level measured in main group on visit 1 was 10,0 (6,1; 16,9) pg/ml, on visit 2 – 14,5 (11,2; 22,9) pg/ml (p=0,02). 6MWT group on visit 1 was 450,0 (375,0; 475,0) meters, on visit 2 – 500,0 (450,0; 525,0) meters (p<0,01). DLco investigated on visit 1 was 48,0 (35,5; 59,3) %, on visit 2 – 47,0 (44,5; 76,5) % (p=0,03). <bold>Conclusion:</bold> Despite improvement of clinical and functional status of patients in late post-COVID-19 period comparing to early post-COVID-19 period endothelin-1 level measured in late post-COVID-19 period is higher than in early post-COVID-19 period. These findings may suggest about progression of endothelial dysfunction from early to late post-COVID-19 period despite improvement in functional lung status.