Cardiovascular disease and the impact of COVID-19Running Head: COVID-19 and cardiovascularAnusha Yoganathan1, Menahel Sajjad1, Amer Harky1,2University of Liverpool, Liverpool, UKDepartment of Cardiothoracic Surgery, Liverpool Heart and Chest, Liverpool, UK

A document by Shivaahnee Raveenthiran. Click on the document to view its contents.

There remains a significant paucity of information evaluating the effect of glycated HbA1c levels and its theorized effect on mortality and morbidity rates following cardiac surgery. Diabetes is a very common comorbidity in patients undergoing open heart surgery as there is shift in patient characteristics and being higher risk. Currently, the evidences are controversial and there is no clear consensus that increased HbA1c levels is associated with an increased perioperative mortality rate. However, reported literature are more commonly able to demonstrate elevated HbA1c levels to be associated with increased rates of wound infection, cardiovascular events and renal failure; thus, higher morbidities postoperatively. This literature review aims to examine the evidence synthesis behind each of morbidities and mortalities associated with open heart surgery and the impact of high HbA1c on the reported outcomes.

The SARS-CoV-2, the causative agent of COVID-19, has been established to gain access to the human cell via the ACE2 receptor similar to its familial coronavirus SARS-CoV which led to the outbreak in 2003. A concern with the newer 2019 coronavirus is its 10-20-fold higher affinity to the ACE2 receptor that of SARS-CoV, aiding its effective human-to-human transmission which has led to this pandemic. ACE2 receptor expression is thought to be upregulated in use with ACE inhibitors. As ACE inhibitors are known to be a used extensively in the treatment of hypertension it was a concern regarding the risk of using these medications alongside a SARS-COV-2 infection. ACE inhibitors are also used in the treatment regime of other common conditions including diabetes and Cardiovascular disease (CVD). It is worth noting that ACE2 expression has found to be upregulated by the use of thiazolidinediones and ibuprofen too. Consequently, the increased expression of ACE2 would facilitate infection with COVID-19. Therefore, it would hypothesise that diabetes and hypertension treatment with ACE2-stimulating drugs would increase the risk of developing severe and fatal COVID-19.