SARS -CORONA VIRUS -2 (COVID-19 disease) is an infectious disease caused by the
SARS-CoV-2 virus The virus enters the body through the nose, eyes, or mouth. The spike
protein binds specifically to the ACE2 receptors present on the type 2 pneumocytes in the
alveoli in the lungs . (Fehr and Perlman, 2015) The binding of the ACE2 receptor allows
the entry of the virus into the host cell .

The virus enters the host cell either by direct cell entry by membrane fusion or by
endocytosis .(Wang , et al. 2008).

ACE inhibitors (angiotensin converting enzyme inhibitors) work by preventing angiotensin
I from converting into angiotensin II. (Byrd,et al. 2019)

ARBs (Angiotensin receptor blockers)reduce the action of the hormone angiotensin II, by
blocking receptors that the hormone acts on, specifically AT1 receptors, which are found
in the heart, blood vessels and kidneys. (Byrd,et al. 2019) ACE inhibitors and ARBs are
used to treat high blood pressure and congestive heart failure, to prevent kidney failure
in patients with high blood pressure or diabetes, and to reduce the risk of stroke.
(Byrd,et al. 2019) Continued use of ACEI/ARB has become controversial in the setting of
COVID-19. The reason for this controversy stems from the fact that ACEIs and ARBs use may
increase the expression of ACE2 receptor in animal-based studies, which is the known
cellular receptor and a necessary entry point for SARS-COV-2 infection, as it has been
indicated that ACE2 expression is downregulated following SARS infection, resulting in
excessive activation of RAS and exacerbated pneumonia progression.(Peng Zhang.et
al.april2020) It has rather been suggested that despite increasing ACE2 levels, ACE
inhibitors and ARBs may rather play a protective role. ACEI, by reducing the conversion
of angiotensin I (ATI) to angiotensin II (ATII) and ARBs, by reducing the binding of ATII
to angiotensin I receptor may tilt the scale suggested by Bombardini et al. in favour of
a protective ACE2-signalling pathway .( Bombardini T, Picano E.2020).

Reynolds et.al (2020)found no association between ACE inhibitors and ARBs and increase
likelihood of a positive test for covid- 19 or its severity. (Reynolds et.al (2020)
However, due to lack of sufficient clinical data supporting either the beneficial or
harmful effects of ACEI/ARBs use in patients with COVID-19, the optimal strategy for the
management of hypertension in COVID-19 is uncertain and remains to be elucidated. So The
aim of this observational study was to determine the association between hypertensive
patients using ACEI/ARBs and morbidity and mortality of COVID-19.