The major finding of the current study is that the CHA2DS2VASC RS has a distinctive ability to predict chest CT-SS in patients with COVID-19. Previous COVID-19 radiology studies do not provide a thorough investigation of the association between the chest CT severity and patient’s comorbidity conditions and laboratory findings. Statistically significant findings in this study can be well used as a guide to screen the patients and effectively identify the ones that may have severe CT involvement on admission in daily practice.
The COVID 19 is a disease that can progress with a severe immune response, as well as have a thrombus burden [25–27]. The mechanism of action of thrombosis has not been fully elucidated. It is thought that the development of coagulopathy adversely affects the prognosis of the patient. D dimer, platelet count, prothrombin time, fibrinogen level should be used to detect the coagulopathy . Increased D-dimer and massive fibrin formation are associated with poor prognosis, prolonged mechanical ventilation, and death [29, 30]. D-dimer levels can also be used to administrate anticoagulants for COVID-19 patients . The CHA2DS2VASC RS predicts the thromboembolic originated ischemic stroke in patients with or without atrial fibrillation (AF) . It also predicts the risk stratification and death in patients with COVID-19 . Recently, Cetinkal et al reported that M-CHA2DS2VASC RS score, derived from CHA2DS2VASC RS, well predicts the in-hospital mortality . Our study indicated that the CT-SS score increases gradually with increasing CHA2DS2VASC RS and M-CHA2DS2VASC RS. Besides, analyses revealed that CHA2DS2VASC RS was more specific than other risk scores.
An irregular immune response is one of the leading causes of death in patients. This immune response progresses with leukocytosis, neutrophilia, monocytosis and lymphopenia. Recently, several investigators reported that NLR can facilitate in categorizing the disease severity and progression in patients, thereby enabling us to make appropriate and informed clinical decisions . Hence, we compared leukocytosis and NLR with the chest CT-SS. Our results suggest that the NLR and leukocytosis correlate with high chest CT-SS. The dysregulated immune response mentioned above may cause macrophage activation syndrome (MAS) in patients. The pathophysiology of MAS has not been fully identified. However, MAS has many different parameters revealed in various studies ; some of which are correlated with the high CT-SS, such as ferritin, LDH, CRP, AST. Therefore, in some studies, these parameters have been identified as a predictor of morbidity and mortality [13, 33].
The relationship between COVID-19 poor outcomes and CR or aortic diameter has not yet been investigated. However, in studies performed with non-covid patients, ascending aorta dilation and increased CR are associated with increased mortality [27, 31]. The current data suggests a statistically significant correlation between high CT-SS and ascending aortic diameter and CR elevation.
If the CT was not applicable, CR was obtained from the posterior-anterior lung film and may provided convenience in clinical practice.
Old age and HT are also associated with increased violence and mortality in COVID-19 patients [6, 10]. Coronary artery disease, one of the vascular diseases, shows that mortality increases in patients with COVID-19 . In our study, patients with vascular diseases, including aortic atheroma plaques, carotid artery stenosis, coronary artery disease, and peripheral artery disease plaques, showed more severe CT involvement. Advanced age, vascular disease, and hypertension, which are elements of both scoring systems, predict an increasing chest CT-SS score. Moreover, CKD was previously reported to be associated with increased mortality in patients with COVID-19 . However, in this study, no statistical relationship was found between CKD and chest CT-SS. Also, recently published studies have shown that a higher initial BUN indicate a higher in-hospital mortality rate. Similarly, in our result demostrated that the chest CT-SS gradually increases as the BUN gets higher, unlike creatinine.
Yang et al. designed the chest CT-SS for rapid and objective assessment in COVID-19 patients . Colombi et al have recently demonstrated that the level of CT involvement shows clinical outcome and mortality . However, there is no study investigating the parameters that predict the degree of involvement in CT using such a large sample and variable size.. In asymptomatic cases may have pneumonia, and clinical deterioration may occur rapidly (16). We think, even if the patient is clinically stable, CT plays a crucial role in decision-making for hospitalization. On the other hand, previous COVID-19 radiology studies do not provide a thorough investigation of the association between the chest CT severity and patient’s comorbidity conditions, clinical scoring systems, and laboratory findings. Statistically significant findings in this study can be well used as a guide to screen the patients and effectively and accurately identify the ones that may have severe CT involvement on admission in daily practice. To the best of our knowledge, this is the first comprehensive analysis of comorbidity conditions or scales, radiological and biochemical characteristics that could aid in evaluating the CT involvement severity.
Limitations of the study
The present study has several limitations. First of all, this was a retrospective study and included a relatively small patient population. Second, the uncertainty of the time interval between onset of symptoms and hospitalization. Lastly, this analysis does not contain information about mortality and long-term follow-up of patients.