Discussion
In this case series, we report the clinical characteristics and risk
factors associated with outcomes in COVID-19 patients admitted to
Shariati hospital, Tehran, Iran. Our study comprehensively describes
clinical presentations and laboratory findings alongside with radiologic
features of a COVID-19 registry among the Iranian population. The study
investigates whether patients who died of COVID-19 are different from
those who recovered in the disease course.
Sex showed no correlation with the mortality rate in our study
population. Deceased cases were significantly older compared to the
surviving patients, which is in line with previous studies (T. Chen et
al., 2020; Zhou et al., 2020). Although the difference in body mass
index (BMI) was not statistically significant within the study subgroups
(p=0.3436), Severe and morbidly obese patients were at higher risk of
death. This was similar to a study by Simonnet et al. that showed a
correlation between BMI above 35 and the severity of the disease, and
also in-hospital death (Simonnet et al., 2020). Unfortunately, due to
the unavailability of BMI in every patient, we were unable to analyze it
further.
Within the presenting symptoms, impaired consciousness, ranging from
mild disorientation to stupor, significantly increased mortality.
Impaired consciousness showed a strong impact on the patients’ final
outcome, affecting the moribund group 13 times more than the survived
ones. In regards to neurologic manifestations, Mao et al. also observed
14.8% of their severe cases had impaired levels of consciousness (Mao
et al., 2020).
Analyzing baseline vital signs values on admission led to impressive
conclusions. Body temperature over 39 °C was strongly suggestive of
mortality in our sample. We noticed systolic blood pressure (SBP) higher
than 140 mmHg on admission lowers the mortality rate down to 60% while
SBP below 100 mmHg increased the risk of mortality up to around three
folds, which is inconsistent with prior observation indicating the
association of higher levels SBP with severe clinical picture (Huang et
al., 2020).
Besides, RR more than 25 and PR values over 100 were significantly
associated with a higher mortality rate. Among them, PR remained
statistically significant in our ultimate logistic regression model with
multiple variants as well. This strong ability of a single component in
physical examination to predict disease course is quite remarkable.
There is a lack of correlation between PR patterns with other
suggestive, inflammatory variables such as CRP and temperature in our
multivariate analysis. Thus, we hypothesize that besides systemic
inflammation responses, higher PR could arise from additional cardiac
involvement by the virus independent of mere inflammation. Similarly, in
a study by Zhou et. Al. PR ≥125 and RR >24 were associated
with a higher risk of mortality, although none of the two variables
remained in the multivariate analysis to assess their correlation to
others (Zhou et al., 2020).
Analyzing the CT scan findings of the patients’ lung involvement
revealed consolidative opacities as the significant imagining
manifestation within our population. Bernheim et al. also suggest
bilateral and peripheral ground-glass and consolidative pulmonary
opacities as the hallmarks of COVID-19 infection on imaging (Bernheim et
al., 2020).
History of HTN prior to hospital admission did not significantly
increase the risk of mortality in our study population. This observation
is inconsistent with prior studies reporting the adverse role of HTN in
the COVID-19 course. HTN is repeatedly reported as the most prevalent
comorbidity among COVID-19 patients (Huang et al., 2020; Wu et al.,
2020). Moreover, a recent meta-analysis by Lippi et al. concluded that
HTN is associated with a 2.5-fold higher risk of severe disease course
or mortality in SARS-Cov-2 infections (Lippi, Wong, & Henry, 2020).
Probably our small number of subjects has not allowed us to detect this
association as evident by our wide 95%CI. In addition, it is not clear
whether poor BP control had contributed to severe symptoms and morbidity
among the hypertensive population, or the mortality was due to the
higher frequency of HTN in the older population, which are more
vulnerable to COVID-19 infection (Schiffrin, Flack, Ito, Muntner, &
Webb, 2020).
We observed that venous blood acidosis was associated with increased
mortality. Severe acidosis (pH of 7.25 or lower) led to 4 times higher
mortality, and PCO2 below 35mmHg was associated with a
2.5-fold increase in mortality. Since no statistically significant
correlation was detected between PCO2 and RR, their
attribution to mortality is independent. In addition, blood bicarbonate
contents below 22 mmol/L led to 2.6 times more mortality than higher
levels.
Along with the existing claim on the higher incidence of in-hospital
death by an increase in neutrophil to lymphocyte ratio (NLR), our data
also revealed higher NLR in the deceased group compared to the recovered
patients. Liu et al. concluded NLR as an independent risk factor of the
in-hospital mortality, especially within their male candidates (Liu et
al., 2020). Besides, Qin et al. noticed a statistically significant
higher number of neutrophils alongside with a lower number of
lymphocytes in severe to critical patients compared to non-severe cases.
This describes the positive association of Neutrophilia or lymphopenia
with disease severity and increased rate of death (Qin et al., 2020).
Ultimately a recent meta-analysis by Lagunas-Rangel confirms the strong
association between higher levels of NLR to death in COVID-19 patients
(Lagunas-Rangel).
Since only 166 cases in our study population had their urine analyzed
the consequent data is not strongly representative. However, serum
creatinine levels alongside proteinuria were significantly detected
higher in the deceased subgroup compared to the recovered patients.
Based on a recent study by Xu et al., ACE2 expresses equally in kidney
cells in comparison to that in the lung, esophagus, small intestine, and
colon. This suggests that the kidney could be considered as an important
target organ for SARS-CoV-2, but further studies should address this
issue (Xu).
It is noteworthy that our study was conducted in a tertiary referral
center which is among the most well-known and well-equipped centers in
Tehran, especially in internal medicine subspecialties. Keeping this in
mind, during the recent outbreak, the number of patients with long-term
rheumatologic complaints was diagnosed with confirmed SARS-COV-2
infection far less than patient with other chronic diseases such as
cancers in our center (11 and 40 respectively). Hence, we hypothesize
that consuming anti-inflammatory drugs would protect the patients from
the new coronavirus infection due to confirmed inflammatory responses
caused by COVID-19.