Impact of Elevated Pulmonary Arterial Wedge Pressure on Safety and Efficacy of Balloon Pulmonary Angioplasty in the Treatment of Chronic Thromboembolic Pulmonary Hypertension

Abstract

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare condition caused by thromboembolic occlusions of the pulmonary arteries and characterized by elevated pulmonary pressure, vascular remodelling, and right ventricular overload, which can be treated effectively with balloon pulmonary angioplasty (BPA). The study aimed to evaluate whether elevated pulmonary arterial wedge pressure (PAWP), associated with left ventricular dysfunction, influences the effectiveness and safety of BPA treatment.

Research question: Does elevated PAWP affect the effectiveness and safety of BPA in patients with CTEPH?

Study design and methods: A retrospective analysis was conducted of 170 patients with CTEPH treated with BPA. Patients were classified into 2 groups: those with normal PAWP and those with elevated PAWP. Hemodynamic parameters, exercise capacity, treatment outcomes, and safety profiles were compared between the groups. Multivariate analysis of overall survival also was performed.

Results: Elevated PAWP was present in 13.5% of patients. The elevated PAWP group was older, had a higher BMI, had higher elevated baseline troponin levels, and had a greater burden of comorbidities-including diabetes, atrial fibrillation, deep vein thrombosis, and chronic kidney disease-than patients with normal PAWP. After treatment, patients with elevated PAWP exhibited significantly smaller reduction in mean pulmonary artery pressure (P = .026) and lower improvement in pulmonary arterial compliance (P = .002) and 6-minute walk distance (P = .011) compared with those with normal PAWP. No significant differences were found in overall survival or adverse event rates observed between the groups.

Interpretation: Elevated PAWP, likely reflecting coexisting left-sided heart dysfunction, was associated with reduced hemodynamic and functional benefits resulting from BPA in patients with CTEPH. Nevertheless, it did not compromise procedural safety or long-term survival, suggesting that BPA remains a viable option in this subgroup, albeit with more modest clinical gains.

Keywords: BPA; CTEPH; PAWP; balloon pulmonary angioplasty; pulmonary arterial wedge pressure.