Balloon Pulmonary Angioplasty in the Management of Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as group 4 pulmonary hypertension (PH) in the 2015 European Society of Cardiology/European Respiratory Society guidelines for the diagnosis and treatment of PH, is regarded as a complication of pulmonary embolism and is caused by the transformation of incompletely resolved thrombi into fibrous tissue that occludes the pulmonary arteries. The current established reference standard curative therapy for CTEPH is pulmonary endarterectomy (PEA), which provides good long-term outcomes with a low mortality rate. For patients with inoperable disease with inaccessible lesions and risk factors for surgery or patients who are diagnosed with residual or recurrent PH after PEA, medical therapy with riociguat is recommended. Balloon pulmonary angioplasty (BPA) is an emerging alternative treatment option for patients with inoperable disease or those with residual or recurrent PH after PEA. BPA has been reported to improve hemodynamics, cardiac function, exercise capacity, and symptoms, as well as PEA. A detailed assessment of thromboembolic lesions in pulmonary arteries by using multiple imaging techniques and treatment strategies with multiple staged procedures based on the patient's condition is important for safe and effective BPA. However, this new technique may still induce life-threatening complications, such as reperfusion pulmonary edema, wire perforation, vessel dissection, and vessel rupture. Meticulous attention to technique is mandatory to minimize serious complications owing to the nature of the anatomic territory involved. The authors summarize the current roles, goals, and complications of BPA in patients with CTEPH and demonstrate ways to formulate an effective and safe treatment strategy. The future perspective of BPA is also discussed. Online supplemental material is available for this article. ©RSNA, 2022.

Beneficial Effect of Endovascular Treatment on Villalta Score in Japanese Patients With Chronic Iliofemoral Venous Thrombosis and Post-Thrombotic Syndrome.

BACKGROUND: Post-thrombotic syndrome (PTS), the most common complication of deep venous thrombosis (DVT), develops in ≥50% of patients with iliofemoral DVT. However, the benefit of endovascular treatment in Japanese patients with chronic DVT and PTS remains unclear. Methods and Results: Between June 2014 and May 2016, endovascular treatment was performed in 11 consecutive Japanese patients with chronic iliofemoral DVT and PTS refractory to anticoagulant therapy and elastic compression stockings. We evaluated the technical success rate, complications, patency, Villalta score, calf circumference, and popliteal vein reflux in both the acute stage (the day following endovascular treatment) and chronic stage (after 6 months). Imaging follow-up included venous duplex scanning and/or magnetic resonance venography. The technical success rate was 81.8%, without complications. In patients with successful intervention, the Villalta score improved significantly, from 9.0±3.7 preoperatively to 3.6±2.5 in the acute phase (P<0.01) and 2.9±2.1 in the chronic phase (P<0.001). The bilateral difference in lower thigh circumference also improved significantly, from 2.6±1.0 cm preoperatively to 1.4±1.0 cm in the chronic phase (P<0.001). However, popliteal vein reflux did not improve. In patients with successful intervention, venous patency rate was 100% at 6 months post-intervention. CONCLUSIONS: Endovascular treatment is safe and effective in Japanese patients with chronic iliofemoral DVT and PTS.

Congenitally Corrected Transposition of the Great Arteries and Situs Inversus in an Octogenarian With Systemic Right Ventricular Failure.

Systemic right ventricular (RV) failure in patients with congenitally corrected transposition of the great arteries (ccTGA), a major cause of mortality in the long-term follow-up, is usually induced by concomitant severe morphologically tricuspid regurgitation (TR) with/without Ebstein's anomaly or progressive conduction tissue disturbances. However, whether or not myocardial fibrosis is a common cause of systemic RV failure in patients with ccTGA remains unclear. Here, we describe an 82-year-old man who had been diagnosed previously as having uncomplicated ccTGA and situs inversus and recently developed systemic RV failure, which was neither associated with severe TR nor advanced conduction tissue abnormalities. Cardiovascular magnetic resonance (CMR) with delayed-enhancement imaging clearly detected extensive myocardial scars (presumably fibrosis) in the RV wall as well as prominent dilatation, hypertrophy, and systolic dysfunction of the systemic RV. These findings suggest that myocardial fibrosis can cause systemic RV failure in elderly patients with uncomplicated ccTGA despite the absence of severe TR or advanced conduction tissue abnormalities and that CMR may be a useful examination to accurately detect systemic RV failure associated with myocardial fibrosis and to subsequently clarify the prognosis in these patients.

Calcium channel blockers in patients with pulmonary arterial hypertension receiving PAH-specific treatment.

BACKGROUND: Calcium channel blockers (CCB) are the first effective therapy for vasoreactive patients with idiopathic pulmonary arterial hypertension (IPAH). However, the advent of modern PAH-specific drugs may undermine the role of vasoreactivity tests and CCB treatment. We aimed to clarify the effect of acute vasoreactivity testing and CCB on patients with IPAH receiving PAH-specific treatment. METHODS: We retrospectively investigated consecutive patients with IPAH (n = 136) diagnosed between 2000 and 2020 and collected data from patients who underwent acute vasoreactivity testing using inhaled nitric oxide (NO). The effects of vasoreactivity testing and CCB therapy were reviewed. Long-term survival was analysed using the Kaplan-Meier method. RESULTS: Acute vasoreactivity testing was performed in 49% of patients with IPAH (n = 67), including 23 patients (34%) receiving PAH-specific therapy without vasoreactivity testing. Eight patients (12%), including three patients (4.4%) receiving PAH-specific therapy, presented acute responses at vasoreactivity testing. They received high-dose CCB therapy (CCB monotherapy for five patients [7.5%] and CCB therapy and PAH-specific therapy for three patients [4.4%]). They presented a significant improvement in clinical parameters and near-normalisation of haemodynamics (mean pulmonary arterial pressure decreased from 46 [interquartile range: 40-49] to 19.5 [interquartile range: 18-23] mmHg [P < .001] at 1-year follow-up). All eight vasoreactive responders receiving CCB therapy showed better long-term survival than non-responders treated with PAH-specific therapy (P < .001). CONCLUSIONS: CCB therapy benefited patients with IPAH who showed acute response to vasoreactivity testing using inhaled NO, even when receiving modern PAH-specific therapy. Acute vasoreactive responders may benefit more from CCB than from PAH-specific therapy.

Recurrent pulmonary hypertension after balloon pulmonary angioplasty for inoperable chronic thromboembolic pulmonary hypertension.

BACKGROUND: Balloon pulmonary angioplasty improves the hemodynamics of patients with inoperable chronic thromboembolic pulmonary hypertension; however, the clinical impact of recurrent pulmonary hypertension after balloon pulmonary angioplasty remains unclear. METHODS: We retrospectively reviewed 262 consecutive patients with chronic thromboembolic pulmonary hypertension who underwent balloon pulmonary angioplasty between July 2009 and December 2020; 158 (65 ± 12 years; males, 20%; median follow-up period, 45 [26, 66] months) with follow-up right heart catheterization and no residual pulmonary hypertension were included. Recurrent pulmonary hypertension was defined as mean pulmonary arterial pressure <25 mm Hg at the first evaluation after balloon pulmonary angioplasty and ≥25 mm Hg at follow-up evaluation requiring additional treatment with balloon pulmonary angioplasty or pulmonary vasodilators. RESULTS: Recurrent pulmonary hypertension was observed in 11 patients; the state occupation probability of recurrence at 5 years was 9.0% (95% confidence interval: 5.0%-18.9%). Only 1 case (0.6%) of recurrent pulmonary hypertension showed vascular restenosis and reocclusion of previously treated lesions, with more significant hemodynamic and exercise capacity deterioration than the other cases. Additional treatments for recurrent pulmonary hypertension (balloon pulmonary angioplasty in 9 patients, pulmonary vasodilators in 4 patients) improved the mean pulmonary arterial pressure from 27 [26, 29] to 22 [19, 23] mm Hg (p < 0.01). Recurrence had a low probability of transitioning to death in an illness-death model. No specific risk factors for recurrent pulmonary hypertension were identified. CONCLUSIONS: Symptomatic recurrent pulmonary hypertension due to vascular restenosis or reocclusion after balloon pulmonary angioplasty was extremely rare. Most cases of recurrent pulmonary hypertension were mild, did not worsen clinically, and had favorable prognoses.

Balloon pulmonary angioplasty for chronic thromboembolic pulmonary disease without pulmonary hypertension.

Balloon pulmonary angioplasty (BPA) is beneficial for patients with chronic thromboembolic pulmonary disease (CTEPD) with pulmonary hypertension (PH). However, the clinical benefit of BPA for the patients with CTEPD without PH remains unknown. In this study, we aimed to evaluate the efficacy, safety, and long-term outcomes of BPA in patients with CTEPD without PH. We retrospectively analyzed the data from 84 CTEPD patients with mean pulmonary artery pressure (mPAP) < 25 mmHg and 39 CTEPD patients with mPAP ≤ 20 mmHg (without PH). Among the 39 patients with CTEPD without PH, 14 underwent BPA (BPA-treated group), and the remaining 25 received no treatment (untreated group). In the patients with CTEPD without PH, BPA led to improvements in symptoms, pulmonary vascular resistance (3.6 ± 1.6 to 2.6 ± 1.1 Wood units, p < 0.001), peak oxygen consumption (16.1 ± 4.0 to 18.8 ± 4.3 mL/kg/min, p = 0.033), minute ventilation versus carbon dioxide production slope (41.4 ± 12.2 to 35.1 ± 6.7, p = 0.026), and mPAP/cardiac output slope (7.0 ± 2.6 to 4.4 ± 2.0 mmHg/L/min, p = 0.004) and facilitated the discontinuation of home oxygenation therapy, with no serious complications. Kaplan-Meier analysis showed no significant difference in all-cause mortality between the untreated and BPA-treated groups. BPA may be a safe treatment option for the patients with CTEPD without PH that can alleviate symptoms, improve exercise capacity, and facilitate weaning from home oxygen therapy. Further prospective randomized trials are needed to confirm these findings.

Clinical outcomes of upfront combination therapy for portopulmonary hypertension.

Background: Limited data exists on upfront combination therapy for portopulmonary hypertension. We evaluated the clinical efficacy, long-term outcomes, and safety of upfront combination therapy in patients with portopulmonary hypertension. Methods: We performed a retrospective, single-center cohort study involving a final analysis of 33 consecutive patients diagnosed with portopulmonary hypertension who were taking pulmonary arterial hypertension-specific medication. We compared hemodynamic parameters, risk profiles, composite clinical worsening events, and safety between monotherapy (n = 23) and upfront combination therapy (n = 10). Results: Twenty-seven patients (82 %) were classified into the Child-Pugh A stage. The change ratios of pulmonary vascular resistance (-32 % vs. -57 %, P = 0.006) were significantly better with upfront combination therapy. Upfront combination therapy also showed significant improvement in risk profiles. Kaplan-Meier analysis showed that the composite event-free rate was significantly lower in patients who received upfront combination therapy than in those who received monotherapy (P = 0.016), although no statistical differences were observed in all-cause death. In the univariate Cox proportional hazards analysis, upfront combination therapy was a factor for decreasing composite clinical worsening outcomes (hazard ratio 0.190, 95 % confidence interval 0.042-0.854; P = 0.030). No significant hepatic impairments were observed over 2 years of follow-up in the upfront combination group. Conclusions: In patients with portopulmonary hypertension, upfront combination therapy significantly improved symptoms and short-term hemodynamics, and reduced long-term clinical worsening events without serious adverse effects. This study's findings suggest that patients with portopulmonary hypertension presenting with mild hepatic impairment benefit from upfront combination therapy.

Three Cases of Unprovoked Venous Thromboembolism with Prothrombin p.Arg596Gln Variant and a Literature Review of Antithrombin Resistance.

Antithrombin resistance (ATR) is a newly identified strong genetic predisposition to venous thromboembolism (VTE) caused by genetic variations in prothrombin with substitutions of Arg at position 596 with either Leu, Gln, or Trp. In the present report, we identified a missense variant p.Arg596Gln in 3 patients from 2 families with unprovoked VTE who each experienced their first VTE event at 19, 67, and 19 years old. The three patients did not show any positive markers for thrombophilia on routine testing, suggesting that patients with unprovoked VTE who have negative findings on thrombophilia tests may carry a prothrombin variant with ATR.

Long-term outcomes of combined pulmonary endarterectomy and additional balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension.

BACKGROUND: The early and long-term outcomes after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) have been established by several high-volume centers, but the impact of postoperative residual pulmonary hypertension affecting postoperative clinical parameters remains unclear. This study aims to investigate the institutional surgical results of PEA and to evaluate the efficacy of additional balloon pulmonary angioplasty (BPA) for residual pulmonary hypertension. PATIENTS AND METHODS: We retrospectively reviewed 222 patients (57.7 ± 12.9 years old, 141 female) who underwent PEA for CTEPH at the National Cerebral and Cardiovascular Center between 2000 and 2020. RESULTS: The preoperative mean pulmonary artery pressure (mPAP) was 45.6 ± 9.7 mmHg and pulmonary vascular resistance (PVR) was 1062 ± 451 dyne*sec/cm-5. Postoperative mPAP (23.4 ± 11 mmHg, 204 patients, P < 0.001) and PVR (419 ± 291 dyne*sec/cm-5, 199 patients, P < 0.001) significantly improved after PEA. Since 2011, 62 patients (28%) underwent BPA after PEA for "catecholamine dependent" residual PH 1 month after PEA in 14, "scheduled" BPA with residual PH 1 year after PEA in 32, and 16 "symptomatic" patients without residual PH. Their mPAP had significantly improved by PEA (48.1 ± 7.7 to 32.0 ± 10.2 mmHg, P < 0.001), and further improved (33.8 ± 11.1 to 26.5 ± 9.1 mmHg, P < 0.001) after BPA. CONCLUSIONS: PEA provided immediate and substantial improvements in pulmonary hemodynamics and favorable long-term survival. In addition, postoperative BPA improved postoperative clinical parameters for eligible patients regardless of the presence of residual PH.

Gut dysbiosis is associated with aortic aneurysm formation and progression in Takayasu arteritis.

BACKGROUND: Takayasu arteritis (TAK) is an autoimmune large vessel vasculitis that affects the aorta and its major branches, eventually leading to the development of aortic aneurysm and vascular stenosis or occlusion. This retrospective and prospective study aimed to investigate whether the gut dysbiosis exists in patients with TAK and to identify specific gut microorganisms related to aortic aneurysm formation/progression in TAK. METHODS: We analysed the faecal microbiome of 76 patients with TAK and 56 healthy controls (HCs) using 16S ribosomal RNA sequencing. We examined the relationship between the composition of the gut microbiota and clinical parameters. RESULTS: The patients with TAK showed an altered gut microbiota with a higher abundance of oral-derived bacteria, such as Streptococcus and Campylobacter, regardless of the disease activity, than HCs. This increase was significantly associated with the administration of a proton pump inhibitor used for preventing gastric ulcers in patients treated with aspirin and glucocorticoids. Among patients taking a proton pump inhibitor, Campylobacter was more frequently detected in those who underwent vascular surgeries and endovascular therapy for aortic dilatation than in those who did not. Among the genus of Campylobacter, Campylobacter gracilis in the gut microbiome was significantly associated with clinical events related to aortic aneurysm formation/worsening in patients with TAK. In a prospective analysis, patients with a gut microbiome positive for Campylobacter were significantly more likely to require interventions for aortic dilatation than those who were negative for Campylobacter. Furthermore, patients with TAK who were positive for C. gracilis by polymerase chain reaction showed a tendency to have severe aortic aneurysms. CONCLUSIONS: A specific increase in oral-derived Campylobacter in the gut may be a novel predictor of aortic aneurysm formation/progression in patients with TAK.

Prognostic impact of follow-up pulmonary vascular resistance in pulmonary arterial hypertension.

OBJECTIVE: Pulmonary arterial hypertension (PAH), caused by pulmonary artery remodelling and increased pulmonary vascular resistance (PVR) due to an unknown mechanism, is an intractable disease with a poor prognosis. The recent development of PAH-specific treatment medications may allow for higher PVR reduction than previously achieved. This study aimed to identify the prognostic significance of follow-up PVR levels achieved shortly after the initiation of targeted treatment in patients with idiopathic/heritable pulmonary arterial hypertension (I/H-PAH). METHODS: We analysed the data of all patients with I/H-PAH admitted to our hospital between 1998 and 2019. We collected data at baseline and during the first invasive haemodynamic evaluation. The primary outcome was death or lung transplantation. RESULTS: Of the 133 treatment-naïve patients enrolled in this study, 47 experienced adverse events during a median follow-up period of 6.4 (IQR 3.5-11.5) years. The median time interval to first follow-up from diagnosis was 162 (IQR 117-253) days. Incidence of the primary outcome was significantly lower in patients who achieved low PVR at follow-up. Of risk factors evaluated at follow-up, the multivariate Cox regression analysis revealed PVR as an independent predictor of the primary outcome (HR 1.103, 95% CI 1.029 to 1.183; p=0.006). The results were consistent across risk profiles according to the simplified risk stratification recommended by the European Society of Cardiology and European Respiratory Society guidelines. CONCLUSION: Follow-up PVR was an independent predictor of transplant-free survival in patients with I/H-PAH. Evaluation of haemodynamic status shortly after initiating treatment may help predict long-term prognosis.

Prognostic value of right ventricular native T1 mapping in pulmonary arterial hypertension.

BACKGROUND: Right ventricular function is an important prognostic marker for pulmonary arterial hypertension. Native T1 mapping using cardiovascular magnetic resonance imaging can characterize the myocardium, but accumulating evidence indicates that T1 values of the septum or ventricular insertion points do not have predictive potential in pulmonary arterial hypertension. We aimed to elucidate whether native T1 values of the right ventricular free wall (RVT1) can predict poor outcomes in patients with pulmonary arterial hypertension. METHODS: This retrospective study included 30 patients with pulmonary arterial hypertension (median age, 45 years; mean pulmonary artery pressure, 41±13 mmHg) and 16 healthy controls (median age, 43 years) who underwent native T1 mapping. RVT1 was obtained from the inferior right ventricular free wall during end systole. RESULTS: Patients with pulmonary arterial hypertension had significantly higher native RVT1 than did controls (1384±74 vs. 1217±57 ms, p<0.001). Compared with T1 values of the septum or ventricular insertion points, RVT1 correlated better with the effective right ventricular elastance index (R = -0.53, p = 0.003), ventricular-arterial uncoupling (R = 0.46, p = 0.013), and serum brain natriuretic peptide levels (R = 0.65, p<0.001). Moreover, the baseline RVT1 was an accurate predictor of the reduced right ventricular ejection fraction at the 12-month follow-up (delta -3%). RVT1 was independently associated with composite events of death or hospitalization from any cause (hazard ratio = 1.02, p = 0.002). CONCLUSIONS: RVT1 was predictive of right ventricular performance and outcomes in patients with pulmonary arterial hypertension. Thus, native T1 mapping in the right ventricular free wall may be an effective prognostic method for pulmonary arterial hypertension.

Development of Pulmonary Arterial Hypertension in a Patient Treated with Qing-Dai (Chinese Herbal Medicine).

Pulmonary arterial hypertension (PAH) is a rare, devastating disease, characterized by elevated pulmonary arterial pressure due to pulmonary microvascular obstruction, which can result in heart failure and death. PAH can be associated with exposure to certain drugs or toxins. We herein report a case in which PAH developed in a patient with refractory ulcerative colitis during treatment with "Qing-Dai," a Chinese herbal medicine. The patient's PAH improved after the discontinuation of Qing-Dai.

Successful multi-step catheter intervention for thrombotic inferior vena cava filter retrieval.

A 45-year-old man, who was implanted with an inferior vena cava (IVC) filter in his infrarenal IVC, had a complication of deep vein thrombosis (DVT) propagation from the IVC, beyond the IVC filter, to the right calf and left external iliac veins. The entire IVC filter was covered with a massive thrombus. We first decided to retrieve the IVC filter itself, which was suspected of causing metallic allergy. The thrombotic IVC filter was successfully retrieved using multi-step catheter intervention. To our knowledge, this is the first case report to describe successful multi-step catheter intervention for retrieval of an IVC filter covered with a massive thrombus. .

Prolonged QRS duration as a predictor of right ventricular dysfunction after balloon pulmonary angioplasty.

BACKGROUND: Balloon pulmonary angioplasty (BPA) has shown beneficial effects for chronic thromboembolic pulmonary hypertension (CTEPH). However, previous studies have shown less cardiac output improvement and symptoms remaining after BPA, implying poor right ventricular (RV) function recovery. Therefore, we investigated the residual RV dysfunction after BPA to reveal risk factors, clinical effects, and possible underlying histopathological mechanisms. METHODS AND RESULTS: We investigated 61 consecutive CTEPH patients who underwent cardiovascular magnetic resonance before and 3 and 12 months after BPA series. Residual dysfunction (RD) of RV was defined as RV end-diastolic volume index >100 ml/m2 or RV ejection fraction (EF) <45% at 12-month follow-up. Patients were divided into RD (44%) and normalized dysfunction (ND) (56%) groups. Compared with the ND group, the RD group had significantly worse World Health Organization (WHO) functional class at follow-up. No significant hemodynamic differences were observed between the groups. On multivariable logistic regression analysis, male sex (odds ratio [OR] 12.5, p = 0.004) and prolonged QRS duration (OR 1.08, p = 0.029) were independently associated with residual RV dysfunction. Additionally, RV histopathology in 11 CTEPH autopsy cases showed that QRS duration was correlated with RV fibrosis area. CONCLUSIONS: Relatively high percentage (44%) of residual RV dysfunction with worse WHO functional class was observed in CTEPH patients even after BPA. Prolonged QRS duration may predict poor recovery in RV function after BPA.

Successful catheter intervention for deep vein thrombosis due to inferior vena cava stenosis after retrieval of a temporary inferior vena cava filter.

Inferior vena cava (IVC) stenosis is a well-known complication of the IVC filter. However, there are no previous reports of IVC stenosis caused by a temporary IVC filter. In this case report, we describe the case of a 35-year-old man who was referred to our center for the treatment of recurrent proximal deep vein thrombosis (DVT) and severe IVC stenosis that occurred after retrieval of a temporary IVC filter. We performed a catheter-directed thrombolysis and balloon angioplasty. DVT resolved effectively, and his leg symptoms resolved. .

Efficacy and safety of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension guided by cone-beam computed tomography and electrocardiogram-gated area detector computed tomography.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by chronic obstructive thrombus and pulmonary hypertension. Balloon pulmonary angioplasty (BPA), an emerging alternative catheter-based treatment for inoperable patients with CTEPH, has not yet been standardised, especially for lesion assessment in distal pulmonary arteries. Recent advancement in computed tomography enables distal CTEPH lesions to be visualized. METHODS: We retrospectively studied 80 consecutive patients with inoperable CTEPH who received BPA guided by cone-beam computed tomography (CT) (CBCT) or electrocardiogram (ECG)-gated area detector CT (ADCT) for target lesion assessment. We collected clinical and hemodynamic data, including procedural complications, before BPA and at 3 months and 1year after BPA. RESULTS: Three hundred eight-five BPA sessions (4.8 sessions/patient) were performed for the lesions of subsegmental arteries (1155 lesions), segmental arteries (738 lesions), and lobar arteries (4 lesions) identified by CBCT or ECG-gated ADCT. Significant improvements in the symptoms, 6-min walk distance, brain natriuretic peptide level, exercise capacity, and haemodynamics were observed 3 months and 1year after BPA. No cases of death or cardiogenic shock with a low rate of severe wire perforation (0.3%) and severe reperfusion oedema (0.3%) were observed. CONCLUSIONS: BPA guided by CBCT or ECG-gated ADCT is effective and remarkably safe in patients with CTEPH . These new advanced CT techniques may be useful in pre-BPA target lesion assessment.

Evaluation of organized thrombus in distal pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension using cone-beam computed tomography.

PURPOSE: Balloon pulmonary angioplasty (BPA) is an emerging treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) patients. However, the approach to use to identify distal thrombi suitable for BPA has not yet been established. The purpose of this work was therefore to evaluate distal chronic thromboembolic lesions for BPA using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Thirty-two patients (men/women: 9/23) with CTEPH who underwent CBCT before BPA were enrolled. We assessed representative forms of chronic thromboembolic lesions in 94 segmental and/or 208 subsegmental branches according to CBCT and compared the results to the findings of selective angiography during BPA. RESULTS: We classified CTEPH lesions into five subtypes as follows: type 1a (11.1 %), webs; type 1b (14.4 %), web with severe narrowing of the subsegmental artery; type 2, (58.2 %) web and slits; type 3 (2.4 %), slits; and type 4 (13.9 %), pouch defect with incomplete obstruction of subsegmental branches or complete occlusion. In our study, 92.6 % of the CTEPH lesions diagnosed by CBCT were highly consistent with the findings of selective angiography during BPA. CONCLUSION: CBCT clearly revealed and classified distal lesions in CTEPH patients. The CBCT findings for distal lesions were highly consistent with those of selective angiography during BPA. CBCT could be a useful modality to detect target lesions before BPA.