Speckle tracking for predicting outcomes of balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

Effects of right ventricular remodeling in chronic thromboembolic pulmonary hypertension on the outcomes of balloon pulmonary angioplasty: a 2D-speckle tracking echocardiography study

BACKGROUND

Balloon pulmonary angioplasty (BPA) improves the prognosis of chronic thromboembolic pulmonary hypertension (CTEPH). Right ventricle (RV) is an important predictor of prognosis in CTEPH patients. 2D-speckle tracking echocardiography (2D-STE) can evaluate RV function. This study aimed to evaluate the effectiveness of BPA in CTEPH patients and to assess the value of 2D-STE in predicting outcomes of BPA.

METHODS

A total of 76 patients with CTEPH underwent 354 BPA sessions from January 2017 to October 2022. Responders were defined as those with mean pulmonary artery pressure (mPAP) ≤ 30 mmHg or those showing ≥ 30% decrease in pulmonary vascular resistance (PVR) after the last BPA session, compared to baseline. Logistic regression analysis was performed to identify predictors of BPA efficacy.

RESULTS

BPA resulted in a significant decrease in mPAP (from 50.8 ± 10.4 mmHg to 35.5 ± 11.9 mmHg, p < 0.001), PVR (from 888.7 ± 363.5 dyn·s·cm-5 to 545.5 ± 383.8 dyn·s·cm-5, p < 0.001), and eccentricity index (from 1.3 to 1.1, p < 0.001), and a significant increase in RV free wall longitudinal strain (RVFWLS: from 15.7% to 21.0%, p < 0.001). Significant improvement was also observed in the 6-min walking distance (from 385.5 m to 454.5 m, p < 0.001). After adjusting for confounders, multivariate analysis showed that RVFWLS was the only independent predictor of BPA efficacy. The optimal RVFWLS cutoff value for predicting BPA responders was 12%.

CONCLUSIONS

BPA was found to reduce pulmonary artery pressure, reverse RV remodeling, and improve exercise capacity. RVFWLS obtained by 2D-STE was an independent predictor of BPA outcomes. Our study may provide a meaningful reference for interventional therapy of CTEPH.

Status and Future Directions for Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Disease With and Without Pulmonary Hypertension: A Scientific Statement From the American Heart Association

Balloon pulmonary angioplasty continues to gain traction as a treatment option for patients with chronic thromboembolic pulmonary disease with and without pulmonary hypertension. Recent European Society of Cardiology guidelines on pulmonary hypertension now give balloon pulmonary angioplasty a Class 1 recommendation for inoperable and residual chronic thromboembolic pulmonary hypertension. Not surprisingly, chronic thromboembolic pulmonary hypertension centers are rapidly initiating balloon pulmonary angioplasty programs. However, we need a comprehensive, expert consensus document outlining critical concepts, including identifying necessary personnel and expertise, criteria for patient selection, and a standardized approach to preprocedural planning and establishing criteria for evaluating procedural efficacy and safety. Given this lack of standards, the balloon pulmonary angioplasty skill set is learned through peer-to-peer contact and training. This document is a state-of-the-art, comprehensive statement from key thought leaders to address this gap in the current clinical practice of balloon pulmonary angioplasty. We summarize the current status of the procedure and provide a consensus opinion on the role of balloon pulmonary angioplasty in the overall care of patients with chronic thromboembolic pulmonary disease with and without pulmonary hypertension. We also identify knowledge gaps, provide guidance for new centers interested in initiating balloon pulmonary angioplasty programs, and highlight future directions and research needs for this emerging therapy.

Evolving Role and Clinical Evidence in the Global Practice of Balloon Pulmonary Angioplasty

Balloon pulmonary angioplasty (BPA) was first described in 2001 and now has evolved into a class I indication for inoperable or residual chronic thromboembolic pulmonary hypertension. This review article aims to describe evidence from studies performed at various pulmonary hypertension (PH) centers across the globe, to better understand the role of BPA in chronic thromboembolic pulmonary disease with and without PH. Additionally, we hope to highlight innovations and the ever-changing safety and efficacy profile of BPA.

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: Clinical Outcomes

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare major vessel pulmonary vascular disease that is characterised by fibrotic obstructions deriving from an organised clot. Recent advances in treatments for CTEPH have significantly improved outcomes. Apart from classical surgical pulmonary endarterectomy, balloon pulmonary angioplasty (BPA) and vasodilator drugs that were tested in randomised controlled trials of non-operable patients are now available. In Europe, CTEPH affects males and females equally. In the first European CTEPH Registry, women with CTEPH underwent pulmonary endarterectomy less frequently than men, especially at low-volume centres. In Japan, CTEPH is more common in females and is predominantly treated by BPA. More data on gender-specific outcomes are expected from the results of the International BPA Registry (NCT03245268).

Update on balloon pulmonary angioplasty for treatment of chronic thromboembolic pulmonary hypertension

PURPOSE OF REVIEW

To provide an update on balloon pulmonary angioplasty (BPA) for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), a pulmonary vascular disease that is characterized by fibro-thrombotic material mechanically obliterating major pulmonary arteries, resulting in increased pulmonary vascular resistance (PVR), progressive pulmonary hypertension (PH) combined with a microscopic pulmonary vasculopathy [1▪▪], right ventricular (RV) failure [2] and premature death.

RECENT FINDINGS

Data from a most recent CTEPH European registry (2015 and 2016) suggest significantly improved survival [3▪] of CTEPH patients compared with survival in the eighties [4], or with data from 2007 and 2009 [5]. Pulmonary endarterectomy (PEA) is still the gold-standard therapy for CTEPH [6,7]. However, only around two thirds of all CTEPH patients are amenable to surgery [3▪,5]. Patients not suitable for PEA and treated conservatively have a poor prognosis [8]. BPA may have a role for this particular group of patients. [9-11]. Currently, BPA programs are available in many countries, with excellent results at expert centers [12-15,16▪,17,18▪▪]. Based on recent data, BPA seems to have a greater impact on symptomatic and hemodynamic improvement than medical therapy with riociguat alone [15].

SUMMARY

The evidence favoring BPA is growing, but there is still a lack of published controlled trials. In addition, treatment concepts including indication, technical performance, use of PH-targeted medication, and the concept of follow-up vary between centers. In addition, there is a significant learning curve impacting outcomes [13]. The data from the International BPA registry will provide answers for some of the open questions.

Effects of BPA on right ventricular mechanical dysfunction in patients with inoperable CTEPH - A cardiac magnetic resonance study

PURPOSE

The aim of this study was to assess effects of balloon pulmonary angioplasty (BPA) on right ventricular (RV) mechanical dysfunction in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) via MRI.

METHOD

MRI at 1.5 Tesla and right heart catheterization were performed before and 6 months after BPA in 30 CTEPH patients (mean age 63.4 ± 10.6 years; 17 female). Feature-tracking strain analysis, including global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain, was performed and compared with right ventricular function, myocardial remodelling (assessed by native T1 times), and pulmonary haemodynamics (mean pulmonary arterial pressure and pulmonary vascular resistance).

RESULTS

RVEF (35.9% to 48.4%) increased and mPAP (42.1 mmHg to 33.1 mmHg) and PVR (551.8 to 377.7 dyn∙s/cm⁵) decreased after BPA (all p < 0.0001). Moreover, RV strain increased (GLS -19.9 to -24.0%, p = 0.0003; GCS -9.4 to -11.0%, p = 0.0022; GRS 38.2 to 50.7%, p = 0.001) and septal native area-adjusted T1 time (AA-T1) decreased (1019.4 to 988.7 ms, p < 0.0001). GLS revealed the best correlations with RVEF (before BPA r = -0.75; after BPA r = -0.54), mPAP (r = 0.36; r = 0.52), PVR (r = 0.49; r = 0.48), and AA-T1 (r = 0.44; 0.19).

CONCLUSION

RV mechanical dysfunction, pulmonary haemodynamics, and myocardial remodelling are markedly improved by BPA. Moreover, RV strain values showed good correlations with RV function, pulmonary haemodynamics, and myocardial remodelling. Therefore, strain analysis might provide new insights regarding therapy outcome, monitoring, and prognosis.

Right Ventricular Function Predicts Adverse Clinical Outcomes in Patients With Chronic Thromboembolic Pulmonary Hypertension: A Three-Dimensional Echocardiographic Study

Background: Right ventricular (RV) function plays a vital role in the prognosis of patients with chronic thromboembolic pulmonary hypertension (CTEPH). We used new machine learning (ML)-based fully automated software to quantify RV function using three-dimensional echocardiography (3DE) to predict adverse clinical outcomes in CTEPH patients.

Methods: A total of 151 consecutive CTEPH patients were registered in this prospective study between April 2015 and July 2019. New ML-based methods were used for data management, and quantitative analysis of RV volume and ejection fraction (RVEF) was performed offline. RV structural and functional parameters were recorded using 3DE. CTEPH was diagnosed using right heart catheterization, and 62 patients underwent cardiac magnetic resonance to assess right heart function. Adverse clinical outcomes were defined as PH-related hospitalization with hemoptysis or increased RV failure, including conditions requiring balloon pulmonary angioplasty or pulmonary endarterectomy, as well as death.

Results: The median follow-up time was 19.7 months (interquartile range, 0.5–54 months). Among the 151 CTEPH patients, 72 experienced adverse clinical outcomes. Multivariate Cox proportional-hazard analysis showed that ML-based 3DE analysis of RVEF was a predictor of adverse clinical outcomes (hazard ratio, 1.576; 95% confidence interval (CI), 1.046~2.372; P = 0.030).

Conclusions: The new ML-based 3DE algorithm is a promising technique for rapid 3D quantification of RV function in CTEPH patients.