Predictors of Echocardiographic Abnormalities in Asymptomatic Individuals with Increased Cardiothoracic Ratio Detected on Chest Radiography

Background: Cardiomegaly detected on chest radiography (CXR) is frequently encountered in clinical practice, even in asymptomatic individuals. However, its diagnostic value for identifying underlying abnormal cardiac structures in this population remains uncertain, and no guideline currently addresses its evaluation. This study investigated the predictors for the echocardiographic abnormalities among asymptomatic individuals with increased cardiothoracic ratio detected on chest radiography. Methodology: This is a cross-sectional study of asymptomatic adults with increased cardiothoracic ratio (CTR) ≥ 0.5 on routine CXR between 2022 and 2025 at Siriraj Hospital, Bangkok, Thailand. A total of 452 participants with increased CTR on CXR who underwent echocardiography within six months were included. Individuals with known structural heart diseases were excluded. Predictive factors were evaluated, including medical history, abnormalities from physical examination, CXR, and electrocardiogram (ECG). Results: Echocardiographic abnormalities were identified in 339 participants (75.0%). In the univariate analysis, age ≥ 65 years, hypertension, chronic kidney disease stage III, presence of a systolic murmur on physical examination, CXR-detected left atrial enlargement (LAE), mediastinal widening on CXR, and ECG-detected left ventricular hypertrophy (LVH) were significantly associated with echocardiographic abnormalities. However, in the multivariable logistic regression analysis, only age ≥ 65 years, hypertension, CXR-detected LAE and ECG-detected LVH remained independent predictors. Conclusion: Age ≥ 65 years, hypertension, CXR-detected LAE and ECG-detected LVH were significant predictors of echocardiographic abnormalities in asymptomatic individuals with cardiomegaly. These findings underscore the importance of integrating clinical assessment with CXR and ECG findings to guide referral decisions for echocardiographic evaluation, particularly in resource-limited settings. Clinical trial number: Not applicable