Introduction: The accuracy of transthoracic echocardiography (TTE) in estimating systolic pulmonary artery pressure (sPAP) by determining right ventricular systolic pressure (RVSP) compared to direct measurement with right heart catheterization (RHC) remains a clinical concern (1). This study aimed to assess the correlation, agreement, and diagnostic accuracy of echocardiographic RVSP in detecting pulmonary hypertension (PH) in a cohort of clinically stable patients undergoing both echocardiography and invasive pressure measurement.
Methods and Results: This retrospective study was conducted at the Cardiology Department of Dubrava University Hospital, including 104 clinically stable patients who underwent TTE and RHC measurements within a 5-day period (Figure 1). Pearson’s correlation analysis demonstrated a strong positive correlation between echocardiographic and invasively measured sPAP (r = 0.709, P < 0.0001). However, Bland-Altman analysis revealed a mean bias of -1.78 mmHg (95% limits of agreement: -29.63 to +26.07 mmHg) for RVSP, indicating substantial individual variability. Lin’s concordance correlation coefficient (CCC = 0.7057) further confirmed moderate agreement between methods. To assess the diagnostic accuracy of echocardiographic RVSP in identifying PH (defined as mean pulmonary artery pressure [mPAP] > 20 mmHg), we performed a receiver operating characteristic (ROC) analysis. The optimal cut-off value for sPAP was 38 mmHg, yielding a sensitivity of 77.6% and a specificity of 66.7%. The area under the curve (AUC) was 0.746, indicating moderate discriminatory power. Despite a good correlation, the relatively wide limits of agreement and moderate specificity suggest that TTE alone may not be sufficient for definitive PH diagnosis.
Conclusions: Echocardiography-derived sPAP correlates well with invasive measurements but demonstrates considerable variability on an individual level. Although the ROC analysis supports its use as a screening tool, TTE alone lacks the precision required for definitive PH diagnosis. The identified cut-off of 38 mmHg provides a reasonable balance of sensitivity and specificity, but RHC remains necessary for confirmation and clinical decision-making. Future studies with larger cohorts are warranted to refine echocardiographic criteria for PH detection.