Assessment of Right Ventricular Pressure in Chronic Thromboembolic Pulmonary Hypertension: Comparison of Diagnostic Modalities and Balloon Pulmonary Angioplasty Outcomes

Abstract

Background/Objectives:: Right ventricular (RV) pressure assessment is crucial in both the diagnosis and follow-up of patients with chronic thromboembolic pulmonary hypertension (CTEPH). While right heart catheterization (RHC) and pulmonary angiography (PA) are gold-standard invasive methods, transthoracic echocardiography (TTE) offers a safer and more accessible alternative. This study aimed to evaluate the reliability of echocardiographic RV pressure estimation compared to invasive techniques and to identify clinical predictors of response to balloon pulmonary angioplasty (BPA). Methods: In this prospective study, 17 patients with confirmed CTEPH underwent RV pressure assessment via TTE, RHC (Swan-Ganz catheterization), and PA within the same hospitalization period. BPA responders were defined based on clinical improvement and were compared to poor responders using pre- and post-treatment parameters. Results: A strong correlation was found between Swan-Ganz and PA-derived pressures (r = 0.96), with a slightly lower correlation between TTE and PA (r = 0.84), and the lowest between TTE and Swan-Ganz (r = 0.78). In the well-responding group, the 6 min walk distance (6MWD) increased by 60 ± 18 m, compared to 12 ± 10 m in poor responders (p < 0.01). NT-proBNP levels decreased by 40% in responders versus 10% in non-responders (p < 0.01). TAPSE improved significantly in responders (from 16.0 ± 2.0 mm to 19.5 ± 2.5 mm, p < 0.01), while RV basal diameter decreased by 15% (p < 0.05). No significant echocardiographic improvement was observed in poor responders. Conclusions: TTE provides a reliable estimate of RV pressure in CTEPH when standardized protocols are followed. NT-proBNP levels and RV size may serve as useful predictors of BPA response.

Keywords: BPA; CTEPH; Swan-Ganz catheterization; echocardiography; pulmonary angiography; right ventricular pressure.

Figure 1

Representative pulmonary angiographic image in CTEPH. This pulmonary angiographic image of the right A9 segment artery and subsegmental branches illustrates the morphological characteristics of vascular lesions in CTEPH. The image highlights segmental or subsegmental filling defects, vascular cut-offs, and perfusion irregularities consistent with thromboembolic involvement. Slit- and web-type lesions are indicated by arrows. Lesion localization, extent, and contrast dynamics are shown to support diagnostic evaluation and therapeutic decision making in pulmonary hypertension or thromboembolic disease.

Figure 2

Balloon pulmonary angioplasty (BPA). In the left panel, the star shows the occluded right A9 segment. In the right panel, the guidewire is advanced into segment A8, following successful recanalization of A9, marked with the star.

Figure 3

Simultaneous multimodal assessment of the right ventricular pressure in patient subgroups—the number of patients evaluated by multiple methods during the same hospitalization.

Figure 4

Simultaneous multimodal assessment of the right ventricular pressure in patient subgroups. Comprehensive comparison of pressure values obtained using three different methodologies: Swan-Ganz catheterization (SG), pulmonary artery pressure measurement during pulmonary angiography (PA), and echocardiographic estimation (Echo). Pressure values are given in mmHg. The top row displays scatter plots with regression lines to assess the correlation between the methods. (A) Measurements by both SG and PA (n = 13), (B) measurements by both SG and Echo (n = 25), (C) measurements by both PA and Echo (n = 22). The bottom row shows histograms with kernel density estimation (KDE) curves to illustrate the distribution patterns of each method’s measurements.

Figure 5

Correlation heatmap. Correlation between right heart pressures measured by different methods—shows strong positive relationships between SG, PA, and echocardiography.