Researchers aim to better understand clinical features associated with COVID-19 mortality

To date, the 2019 coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in over 142.2 million cases and over 3 million deaths around the world.

To mitigate the impact of any infectious disease, it is necessary to understand how its causative pathogen is transmitted as well as its clinical characteristics. As has been observed since the onset of the current pandemic, COVID-19 has exhibited a wide range of clinical features and disease outcomes. Despite numerous studies focused on its risk factors and clinical features, the important factors in the death rate of COVID-19 are not yet sufficiently understood.

To explore these characteristics, an interdisciplinary team of researchers studied the important factors and their influence on the death of a COVID-19 patient. In this study, the team suggests presenting some features studied for the first time. The team’s findings were recently published medRxiv* on the pre-print server.

The study showed a significant association between mortality and certain risk factors such as old age, headaches, chest pain, respiratory distress, low respiratory rate, oxygen saturation less than 93%, the need for mechanical ventilation, computed tomography evidence, hospitalizations and history of hypertension. , neurological disorders or any cardiovascular disease.

In contrast, they found no significant association between mortality and gender, fever, myalgia, dizziness, seizures, abdominal pain, nausea, vomiting, diarrhea, or anorexia.

The researchers said this study could help better clinical management of patients with COVID-19.

COVID-19 is often manifested by fever, continuous dry cough, and shortness of breath. Chest x-rays typically show frosted glass opacity and multiple mottling in patients who develop COVID-19-related pneumonia.

Other clinical findings typically found in COVID-19 patients include a decrease in eosinophils and lymphocyte count; lower median hemoglobin values ​​and an increase in the number of neutrophils; WBC and serum alanine aminotransferase (ALT) levels; aspartate aminotransferase (AST); lactate dehydrogenase (LDH); and C-reactive protein (CRP). In the case of patients with severe COVID-19, initial serum CRP levels are considered to be an independent predictor.

Since the angiotensin converting enzyme 2 (ACE2) receptors of the viral spike protein are widely expressed in various organs, infection with SARS-CoV-2 can cause gastrointestinal (lung damage). intestinal, hepatic, renal, central nervous system, cardiovascular and eye damage. In the case of Acute Respiratory Distress Syndrome (ARDS), patients’ condition deteriorates rapidly with the “cytokine storm”, resulting in fatal failure of several organs.

Elevated D-dimer levels, reflecting the risk of disseminated coagulopathy in patients with severe COVID-19, are also seen with increased severity.

Previous studies on risk factors and outcomes related to COVID-19 have targeted diabetes, heart damage and high-dose corticosteroid use, availability of health resources, selenium status, markers of damage heart disease, statin use, ICU admission, nutritional status and also air pollution levels.

However, the researchers note that a full list of clinical features associated with COVID-19 mortality has not yet appeared in the existing literature. They sought to address this issue and believe that the effect of certain risk factors and associated symptoms of COVID-19 mortality were first investigated in their study.

The study was conducted between March 2020 and November 2020 and included a cohort of 3,008 patients with COVID-19; most were Iranian nationals (94.5%) and the rest were Afghan nationals (5.5%).

The researchers found that while gender did not affect mortality, there was a significant difference between patient mortality and age, infection time, and inpatient ward (isolated ward, intensive care unit , normal service).

They found that there was a significant difference between mortality and headaches in patients infected with COVID-19. The presentation of chest pain, decreased level of consciousness, respiratory distress, oxygen saturation less than 93%, lower respiratory rate, and the need for mechanical ventilation were significantly associated with COVID-19-related mortality.

The researchers tabulated the effect of different characteristics (early symptoms) on death rates. Most of the key factors were consistent with previous observations. Researchers noted that the following are not associated with COVID-19-related mortality: opium addiction, smoking, pregnancy, diabetes mellitus, underlying cancer, liver disease, lung disease, asthma, kidney disease , chronic hematological diseases, other chronic diseases, and receiving immunosuppressive drugs.

However, they reported that underlying cardiovascular disease, hypertension, and neurological disease were associated with mortality from COVID-19.

Researchers observed a significant association between mortality from COVID-19 and age against the background of immune deficiency and the increased possibility of developing cardiovascular and respiratory disease in the elderly.

Notably, they found no relationship between COVID-19 mortality and cancer – a finding that contradicts some previous studies. This finding could be due to the other populations observed in this study.

The researchers warn that while this study has highlighted some important characteristics of COVID-19 mortality, its geographic and demographic reach is limited. Factors associated with mortality may differ in other regions.

The team’s findings may help facilitate further research in the area to corroborate or refine their findings. They can also help clinicians better manage, triage, and care for patients with COVID-19 with clinical features associated with severe disease outcomes.

*Important Notice

medRxiv publishes preliminary scientific reports which are not peer reviewed and, therefore, should not be considered conclusive, guide clinical practice / health-related behavior, or be treated as established information.

Journal reference:

  • Rahimeh Eskandarian, Zahra Alizadeh Sani, Mohaddeseh Behjati, Mehrdad Zahmatkesh, Azadeh Haddadi, Kourosh Kakhi, Mohamad Roshanzamir, Afshin Shoeibi, Roohallah Alizadehsani, Sadiq Hussain, Fahravahhahavid Khozhavid Khozhavid Keyehani, Muhammad Kharavidi Kharavidikh, Khozhavid Khozhaviha, Kharavid, Khuzhavid Hussain, Khhavozhavid Khozhavi Shaikh Keyhani, Islam Nahavid, Fahravidy Sheikh Keyhani, Vahhavid Sheikh Keyhani, Islam. Identification of clinical features associated with mortality in COVID-19 patients. medRxiv 2021.04.19.21255715; doi:,