Amidst the pandemic that has mesmerized the entire world, as it has not spared anyone according to any specific characteristic, some conditions have, in fact, emerged as risk factors for a complicated evolution of COVID-19. Older age, cardiovascular disease including hypertension, diabetes and pulmonary disease, have been associated with more severe presentations and/or adverse prognosis. In this letter to the editor, we propose that the link between cardiovascular and metabolic diseases and the higher incidence and worse prognosis of COVID-19 patients is the (micro) vascular endothelium.