Impact of Subcarinal Angle on Parenchymal Involvement and Disease Severity in COVID-19 Pneumonia: A Retrospective Analysis

This study aims to examine the relationship between the subcarinal angle (SCA) and the risk and severity of parenchymal involvement in COVID-19 positive patients. This retrospective study involved 2006 patients, categorized into a study group of 1003 COVID-19 positive patients with parenchymal involvement and a control group of 1003 patients with COVID-19-like symptoms but without parenchymal involvement. Receiver Operating Characteristic (ROC) analysis was used to establish cut-off values for SCA and age that predict disease progression and severity. The study and control groups had mean ages of 51.80 and 45.76 years, respectively. Males had a higher frequency of parenchymal involvement (p = 0.003). ROC analysis identified SCA cut-offs of 34.5°–35.5° for the right SCA, 39.5°–40.5° for the left SCA, and 74.5°–75.5° for the total SCA. Age cut-offs were set at 47 years for increased risk and 54 years for greater severity of involvement. SCA values above 36° for the right, 42° for the left, and 77° for the total significantly increased the Tomographic Severity Score (TSS), indicating more severe disease. The TSS was higher in males and positively correlated with age and SCA, suggesting that both factors are important in predicting the severity of COVID-19 pneumonia. SCA is a key predictor of the severity and extent of COVID-19 pneumonia. Measuring SCA alongside age can enhance early risk assessment, disease management, and the implementation of timely and effective interventions, potentially reducing the morbidity and mortality associated with the disease.