Discussion
In our retrospective cohort study, among 991 patients suffering severe
to criticalCOVID-19, atorvastatin which were administered for 421 of the
patients was associated with a significant decrease in mortality
(HR=0.679), the need for mechanical ventilation (HR=0.602), and hospital
length of stay. Very little was found in the literature about the role
of statins in the management of patients with COVID 19. In line with our
study, data from the largest cohort study from China by Zhang et al,
demonstrated that in-hospital use of statins improved survival among
COVID-19 patients (HR=0.58). In this retrospective study, which included
1219 patients who used a statin, 28-day all-cause mortality risk was
5.2% and 9.4% in the statin and none statin users, respectively19. The lower mortality rate in this study compared to
our results could be due to including moderate cases in the study by
Zhang et al. which were not included in our study. Another study
enrolled 71 patients with a pre-existing chronic cardiovascular disease,
and in accordance with our findings, the mortality rate of patients who
received statins was lower compared to the group of patients without
statins (21.4% vs. 34.5%; p<0.05), and in their subgroup
analysis, it is reported a significant reduction in mortality in the
patients who were taking atorvastatin compared to non-statin users and
patients who were taking other statins (P=0.025)20. In
another retrospective cohort study, which compared intensive-care unit
(ICU) admission, invasive mechanical ventilation rate, and death between
statin users and non-statin users, ICU admission was lower in the statin
group but other outcomes were not different between the two groups21. Another retrospective multicenter cohort study
showed a significant association between statin intake in 31 subjects
and the absence of symptoms during COVID-19 with an odds ratio of 2.91,
nevertheless, there were no effects on serious clinical
outcomes22.
Based on the result from our study which is in accordance with the
previously performed studies, reduced need for mechanical ventilation as
two important measures for pulmonary function, we could say that
atorvastatin administration strongly reduces the disease severity by
inhibition of the inflammatory process during the disease course. Also,
these effects alongside to reduction in mortality rate which was
statistically significant, make the medication an important choice of
add-on therapy. Based on the significance of the mechanisms involved in
the beneficial effect of the atorvastatin in the course of COVID-19, and
the clinically proven efficacy, we could consider it in the treatment of
patients who suffer from a severe form of the disease. It is important
to note that, we studied the effect of the atorvastatin on the outcome
of the patients as add-on therapy and we should not forget about the
importance of early antiviral agents administration as potent inhibitors
of the viral replication which could reduce the hospital length of stay23, the role of potent anti-inflammatory agents such
as corticosteroids and interleukin pathways inhibitors on mortality and
severity in the treatment of the COVID-19 24-27.
By considering the result of the study, we should be aware of the
limitation we are facing in this study. First, this study was performed
by a retrospective method which makes further randomized controlled
trials emerge. Second, although we adjusted potential confounders to
reduce the study results bias, it could be possible that some unmeasured
factors such as prehospital used medication, the socioeconomic situation
could interfere with the results. Third, we could expect that the result
could be affected by the data from other institutions and a multicentric
designed prospective study may be needed. Fourth, as we included data of
the hospitalized patients with the severe form of the disease,
extrapolation of the results to non-hospitalized patients with moderate
disease severity may not be possible.