Correlation between Echocardiography and Cardiac Catheterization for the Assessment of Pulmonary Hypertension in Pediatric Patients

Introduction Cardiac catheterization is widely considered the “gold standard” for the diagnosis of pulmonary hypertension. However, its routine use is limited due to its invasive nature. Therefore, the aim of this study was to evaluate the correlation between pulmonary artery pressures obtained by various parameters of transthoracic echocardiography and cardiac catheterization. Methods This study includes 50 consecutive patients with intracardiac shunt lesions diagnosed with severe pulmonary hypertension on echocardiography and admitted for cardiac catheterization at the National Institute of Cardiovascular Diseases (NICVD) in Karachi, Pakistan. Cardiac catheterization and transthoracic echocardiography were performed in all patients simultaneously and systolic (sPAP) and mean pulmonary artery pressure (mPAP) were assessed with both modalities. Correlations and agreement, in terms of Bland-Altman plot, were computed between both modalities for sPAP and mPAP. Results Out of 50 patients, 46% (23) were male and mean age was 7.49 ± 4.45 years. On cardiac catheterization, sPAP was 93.92 ± 17.91 mmHg and mPAP was 67.0 ± 14.28 mmHg. Correlation between cardiac catheterization and echocardiography for the assessment of sPAP was 0.917 (p<0.001), and mPAP was 0.832 (p<0.001) for mean gradient of tricuspid regurgitation (PGTRmean), 0.749 (p<0.001) for peak gradient of pulmonary regurgitation (PGPRpeak), 0.691 (p<0.001) for Acceleration time across right ventricular outflow tract (RVOT), and 0.752 (p<0.001) for end gradient of pulmonary regurgitation (PGPRend). Bland-Altman plot showed moderate agreement between two modalities. Conclusion A positive but modest correlation was observed between hemodynamic parameters of transthoracic echocardiography and cardiac catheterization for assessment of pulmonary artery pressures. Transthoracic echocardiography can reliably be used as an initial non-invasive modality for the assessment of pulmonary artery hypertension and can obviate the need of right heart catheterization in some patient especially with mild pulmonary hypertension.