Prolonged catheter balloon inflation for the treatment of hemoptysis complicating balloon pulmonary angioplasty

Changes in Inflammatory Markers in Patients with Chronic Thromboembolic Pulmonary Hypertension Treated with Balloon Pulmonary Angioplasty

Background: Inflammatory response and endothelial dysfunction contribute to the progression of chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to assess changes in biomarkers involved in those processes in inoperable CTEPH patients treated with balloon pulmonary angioplasty (BPA). Methods: We enrolled 20 patients with inoperable CTEPH qualified for BPA and a control group. Interleukin 6, 8, 10 (IL-6, IL-8, IL-10), monocyte chemoattractant protein-1 (MCP-1), and C-reactive protein (hsCRP) constituted the markers of systemic inflammation. Endothelin 1 (ET-1) served as a marker of endothelial dysfunction. Selected markers were assessed before the BPA treatment, 24 h after the first BPA, and six months after completion of the BPA treatment. Results: At baseline, the CTEPH patients had increased serum concentrations of IL-6, IL-8 and ET-1. Twenty-four hours after a BPA session, we observed an increase in concentrations of IL-6 (∆ = 3.67 (1.41; 7.16); p < 0.001), of IL-10 (∆ = 0.25 (0; 0.47); p = 0.003), of MCP-1 (∆ = 111 (60.1; 202.8); p = 0.002), and of hsCRP (∆ = 4.81 (3.46; 8.47); p < 0.001). Six months after completion of the BPA treatment, there was a decrease in concentrations of IL-6 (∆ = −1.61 (−3.11; −0.20); p = 0.03), of IL8 (∆ = −3.24 (−7.72; 0.82); p = 0.01), and of ET-1 (∆ = −0.47 (−0.96; 0.05); p = 0.005). Conclusions: Patients with inoperable CTEPH exhibit increased systemic inflammation and endothelial dysfunction, which improves after completion of the BPA treatment. A single BPA session evokes an acute inflammatory response.

Virtual Histology to Evaluate Mechanisms of Pulmonary Artery Lumen Enlargement in Response to Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) results from an obstruction of pulmonary arteries (PAs) by organized thrombi. The stenosed PAs are targeted during balloon pulmonary angioplasty (BPA). We aimed to evaluate the mechanism of BPA in inoperable patients with CTEPH. We analyzed stenosed PAs with intravascular grey-scale ultrasound (IVUS) to determine the cross-sectional area (CSA) of arterial lumen and of organized thrombi. The composition of organized thrombi was assessed using virtual histology. We distinguished two mechanisms of BPA: Type A with dominant vessel stretching, and type B with dominant thrombus compression. PAs were assessed before (n = 159) and after (n = 98) BPA in 20 consecutive patients. Organized thrombi were composed of dark-green (57.1 (48.0–64.0)%), light-green (34.0 (21.4–46.4)%), red (6.4 (2.9–11.7)%;) and white (0.2 (0.0–0.9)%) components. The mechanism type depended on vessel diameter (OR = 1.09(1.01–1.17); p = 0.03). In type B mechanism, decrease in the amount of light-green component positively correlated with an increase in lumen area after BPA (r = 0.50; p = 0.001). The mechanism of BPA depends on the diameter of the vessel. Dilation of more proximal PAs depends mainly on stretching of the vessel wall while dilation of smaller PAs depends on compression of the organized thrombi. The composition of the organized thrombi contributes to the effect of BPA.

Pulmonary Artery Elastic Properties After Balloon Pulmonary Angioplasty in Patients With Inoperable Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

A significant proportion of the right ventricular afterload is determined by the elastic properties of the pulmonary artery (PA). We aimed to assess the effect of balloon pulmonary angioplasty (BPA) on PA elastic properties in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

We enrolled adult patients with CTEPH treated with BPA and controls without PH. Total PA compliance (CPa) was calculated as stroke volume/PA pulse pressure. PA distensibility (DC) and compliance (CC) coefficients were assessed by intravascular ultrasound to denote local elastic properties of the treated PA segments.

RESULTS

We performed 103 BPA sessions in 17 patients with CTEPH (5 men [29%], aged 66 [64 to 73] years) who were followed for 6 (5 to 7) months after the last BPA. The median time between BPA sessions was 39 (28 to 52) days. The CPa, CC, and DC were lower in patients with CTEPH than in controls without PH (n = 10). Complete BPA treatment led to increase of CPa from 1.02 (0.70 to 1.39) to 2.08 (1.49 to 2.39) mL/mm Hg (P < 0.001) at the 6-month follow up, and this increase was in proportion to a decrease in pulmonary vascular resistance (PVR) (R² = 0.74; P = 0.001). CPa increased immediately after BPA session by 0.13 (-0.05; 0.33) mL/mm Hg (P = 0.001) and remained unchanged until the next BPA session. CC and DC exhibited no immediate change after catheter balloon inflation (Δ=0 [-0.03; 0.02] mm²/mm Hg, P = 0.52, and Δ = 0 [-0.13; 0.13] %/mm Hg, P = 0.91, respectively) and remained unchanged at the 6-month follow-up.

CONCLUSIONS

BPA improved total CPa in proportion to a decrease in PVR despite no improvement in local elastic properties of the treated PA segments.