Retrograde Approach in Balloon Pulmonary Angioplasty

Technical Considerations for Performing Safe and Effective Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a late complication of acute pulmonary thromboembolism owing to incomplete clot dissolution in pulmonary artery. Pulmonary endarterectomy is the first-line treatment for CTEPH. However, 40% of patients are not candidates for surgery because of distal lesions or age. Balloon pulmonary angioplasty (BPA), a catheter-based intervention, is increasingly being used worldwide for treating inoperable CTEPH. Previous BPA strategy had a major concern of reperfusion pulmonary edema as a complication. However, recent refined strategies promise safe and effective BPA. Five-year survival rate after BPA is 90% for inoperable CTEPH, comparable with that of operable CTEPH.

Preprocedural frailty is strongly associated with symptoms after balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has improved the survival rate of patients with chronic thromboembolic pulmonary hypertension (CTEPH). The resolution of symptoms is one of the remaining goals of BPA. Frailty affects the outcome of cardiovascular diseases or treatments. The aim of this study is to assess the association between frailty and outcome of BPA. The resolution of symptoms is evaluated by the post-BPA World Health Organization functional class (WHO-FC). A total of 54 patients with CTEPH were divided into 2 groups by post-BPA WHO-FC (WHO-FC I group; n = 34 vs. WHO-FC ≥ II group; n = 20). Frailty was assessed by physicians using the clinical frailty scale (CFS) at the point of patient admission for their first BPA sessions. Compared to the WHO-FC ≥ II group, the WHO-FC I group was younger (65.6 ± 13.9 years vs. 74.3 ± 8.0 years) and had a lower CFS (3 [3, 4] vs. 4 [4, 6]) (median [25th, 75th percentiles]). The WHO-FC I achievement rates for each CFS score were CFS 3: 82.8%; 4: 53.8%; 5: 25.0%; 6: 33.3%; and 7: 20.0%. Logistic regression analysis showed that CFS was an independent predictor of WHO-FC I achievement (odds ratio 0.50, p = 0.012), but pre-BPA hemodynamic parameters and age were not independent predictors. Whether WHO-FC I can be achieved is predicted by pre-BPA patient frailty but not by pre-BPA hemodynamic parameters and age.

Impact and safety of balloon pulmonary angioplasty for elderly patients

Recently, balloon pulmonary angioplasty (BPA) for chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic pulmonary disease (CTEPD) has become an established procedure with stable results. The number of elderly CTEPH/CTEPD patients has also increased due to the widespread recognition of the disease concept. However, the reports of BPA in the elderly are limited. The aim of this study was to evaluate the efficacy and safety of BPA in elderly patients (>80 years). From April 2016 to December 2020, 344 BPA sessions (74 patients) were performed. The safety and efficacy of the BPA procedures were compared in the younger group (<80 years; 278 sessions) and the elderly group (≥80 years; 66 sessions). The hemodynamic parameters were significantly improved in both groups (mean pulmonary arterial pressure: 34.4 ± 9.9 → 21.2 ± 6.2 mmHg, p < 0.001 and 33.2 ± 9.6 → 21.8 ± 8.5 mmHg, p < 0.001; pulmonary vascular resistance: 474.5 ± 248.6 → 201.3 ± 108.7 dyne sec cm⁻⁵, p < 0.001 and 496.4 ± 290.9 → 260.5 ± 120.2 dyne sec cm⁻⁵, p = 0.002, in younger and elderly group, respectively). The rate of death within 30 days of BPA (0.3% vs. 0%, p = 1.000) and use of positive pressure ventilation (1.4% vs. 3.0%, p = 0.600) were not different between the groups (younger vs. elderly, respectively). BPA significantly improved the hemodynamic parameters of elderly CTEPH/CTEPD patients, and the safety is comparable to that of younger patients.

Successful depiction of systemic collateral supply to pulmonary artery in CTEPH using time-resolved 4D CT angiography: a case report

A 49-year-old man with CTEPH (pre-procedural mean pulmonary artery pressure: 36 mmHg) underwent balloon pulmonary angioplasty. Chronic total occlusion of the left inferior pulmonary artery trunk was observed. To evaluate the collateral vessels of the chronic total occlusion, 4D-CTA was performed. The examination was performed using a 256-row detector CT system using the test bolus tracking method. 4D-CTA showed the bronchial artery-to-left inferior pulmonary artery collateral supply, which was confirmed by a selective bronchial artery angiography. The patient’s symptoms improved with balloon pulmonary angioplasty of the other stenotic lesions. 4D-CTA can noninvasively evaluate the anatomy and hemodynamics of multiple systemic collaterals simultaneously. This technique can support interventions in systemic artery-to-pulmonary artery collaterals, such as embolization, and could be helpful in challenging balloon pulmonary angioplasty interventions for chronic total occlusion to identify vessel structures distal to the chronic total occlusion and collateral channels for a retrograde approach.

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: Initial Single-Center Experience

Objective

To evaluate the safety and efficacy of balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) seen at a US medical center.

Patients and Methods

Patients with inoperable or residual postendarterectomy CTEPH who underwent BPA at Mayo Clinic in Rochester, Minnesota, between August 11, 2014, and May 17, 2018, were included. Invasive hemodynamic, clinical, laboratory, and echocardiographic data were collected and analyzed retrospectively.

Results

We identified 31 patients (26 with inoperable CTEPH and 5 with residual postendarterectomy CTEPH) who underwent 75 BPA procedures performed in a staged manner to reduce complications. The median number of sessions was 2 (interquartile range [IQR], 1-3) per patient, and the number of vessels treated per session was 3 (IQR, 2-3). Of the 31 patients, 24 (77.4%) were taking pulmonary vasodilators and 22 (71.0%) were taking riociguat. The mean pulmonary arterial pressure decreased from 40 mm Hg (IQR, 29-48 mm Hg) to 29 mm Hg (IQR, 25-37 mm Hg; P<.001); pulmonary vascular resistance decreased from 5.5 Wood units (WU) (IQR, 3.0-7.6 WU) to 3.3 WU (2.2-5.2 WU; P<.001). The follow-up 6-minute walk test was performed in 13 patients and improved from 402 m (IQR, 311-439 m) to 439 m (366-510 m; P=.001). Of the 31 patients, 19 (61.3%) had improvement in New York Heart Association functional class. The mean ± SD nadir of minute ventilation/carbon dioxide production decreased by 3.4±5.5 (P=.03), reflecting improved ventilatory efficiency. Complications included hemoptysis requiring overnight intensive care unit observation (n=1) and cardiac tamponade requiring pericardiocentesis (n=1). One patient had reperfusion injury requiring intubation, recovered, and was dismissed to home but died unexpectedly within less than 30 days of the procedure. Serious complications occurred in 3 of the 75 BPA procedures (4.0%).

Conclusion

Our experience with BPA revealed that this procedure has acceptable risk and improves hemodynamics, functional class, and exercise tolerance in patients with inoperable or residual CTEPH.

Working backward: Retrograde balloon angioplasty of atretic arteries in chronic thromboembolic pulmonary hypertension

We describe a patient with chronic thromboembolic pulmonary hypertension who presented to the pediatric cardiac catheterization laboratory for peripheral pulmonary artery recanalization and angioplasty. This case report outlines serial pulmonary arterial rehabilitation via a retrograde approach through intrapulmonary collateral arterial connections.

Residual high intrapulmonary shunt fraction limits exercise capacity in patients treated with balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has emerged as a new treatment strategy for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Improvements in hemodynamic parameters after BPA have been reported, but some patients continue to suffer from reduced exercise tolerance even after the normalization of hemodynamic parameters following BPA. As the amelioration of hemodynamic parameters is reportedly achieved via BPA, we hypothesized that the limiting factors for exercise tolerance in these patients are related to respiratory function. Therefore, we investigated the associations between respiratory function and exercise tolerance, and the mechanisms underlying respiratory dysfunction in patients after BPA. We analyzed 62 patients with CTEPH who underwent 1-year follow-up after BPA. Predictors for reduced exercise tolerance after BPA determined with six-minute walk test were sought from pulmonary hemodynamic and respiratory parameters using logistic regression analysis. After multivariate adjustments, high mean right atrium pressure (mRAP) and high alveolar-arterial oxygen gradient (A-aDO₂) were significant predictors for reduced exercise tolerance. Next, we analyzed factors associated with high A-aDO2. Among the pathophysiological causes of high A-aDO2, including ventilation, diffusing capacity, and low ventilation-perfusion ratio, only low ventilation-perfusion ratio caused by high intrapulmonary shunt fraction was associated with high A-aDO₂. Impaired oxygenation due to residual high intrapulmonary shunt fraction was associated with reduced exercise tolerance in patients with CTEPH, after receiving BPA.

Balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to result from incomplete resolution of pulmonary thromboemboli that undergo organisation into fibrous tissue within pulmonary arterial branches, filling pulmonary arterial lumina with collagenous obstructions. The treatment of choice is pulmonary endarterectomy (PEA) in CTEPH centres, which has low post-operative mortality and good long-term survival. For patients ineligible for PEA or who have recurrent or persistent pulmonary hypertension after surgery, medical treatment with riociguat is beneficial. In addition, percutaneous balloon pulmonary angioplasty (BPA) is an emerging option, and promises haemodynamic and functional benefits for inoperable patients. In contrast to conventional angioplasty, BPA with undersized balloons over guide wires exclusively breaks intraluminal webs and bands, without dissecting medial vessel layers, and repeat sessions are generally required. Observational studies report that BPA improves haemodynamics, symptoms and functional capacity in patients with CTEPH, but controlled trials with long-term follow-up are needed. Complications include haemoptysis, wire injury, vessel dissection, vessel rupture, reperfusion pulmonary oedema, pulmonary parenchymal bleeding and haemorrhagic pleural effusions. This review summarises the available evidence for BPA, patient selection, recent technical refinements and periprocedural imaging, and discusses the potential future role of BPA in the management of CTEPH.

Balloon pulmonary angioplasty is an emerging percutaneous vascular intervention for non-operable CTEPHhttp://ow.ly/tIN3309hys3