Design and Baseline Data for a Prospective Observational Study of Rivaroxaban in Patients with Venous Thromboembolism in Japan (XASSENT)

Background  The efficacy and safety of rivaroxaban have been demonstrated in phase 3 trials of patients with venous thromboembolism (VTE; pulmonary embolism [PE] and deep vein thrombosis [DVT]). Data regarding rivaroxaban treatment of VTE in routine Japanese clinical practice remain limited.

Objectives  XASSENT will evaluate rivaroxaban treatment of VTE in real-world Japanese clinical practice. We report the study design and baseline patient characteristics.

Methods  XASSENT (NCT02558465) is an open-label, prospective observational, post-marketing surveillance cohort study in patients receiving rivaroxaban treatment for VTE. Enrolment took place between November 2015 and March 2018. XASSENT will follow patients for up to 2 years. Primary outcome variables: major bleeding and symptomatic recurrent VTE. Statistical analyses are exploratory and descriptive.

Results  Baseline patient characteristics at June 2020 ( n  = 2,299) are presented (58.2% female; mean age 66.7 years; mean weight 60.9 kg). The population encompasses patients with wide-ranging characteristics including older age, low weight, and renal dysfunction. Most participants (67.6%) had a history of VTE risk factors at baseline. Half of the population (50.4%) had DVT only; 41.4% had DVT with PE; 8.2% had PE only. Overall, 68.4% were inpatients and 77.1% had symptomatic VTE. Rivaroxaban was prescribed for initial treatment in 84.6% of patients and maintenance treatment in 15.4%. Most were prescribed the approved dose of rivaroxaban for initial (30 mg daily; 84.4%) or maintenance (15 mg daily; 81.9%) treatment of VTE in Japan. The most common reason for selecting non-recommended dose was ‘elderly’.

Conclusions  Results from XASSENT will complement phase 3 trial data and inform clinical practice.

Total thrombus-formation analysis system (T-TAS) can predict target lesion revascularization in patients undergoing endovascular therapy for critical limb ischemia

Background

Despite of the development of endovascular therapy (EVT), the frequency of target lesion revascularization (TLR) after EVT in patients with critical limb ischemia (CLI) is still high. Recent histrogical study suggested the possibility of thromboembolic phenomenon in the development of CLI; however, there is few monitoring system of total thrombogenicity in perioperative period of EVT in CLI patients. The total thrombus-formation analysis system (T-TAS), a novel system for quantitatively analyzing thrombus formation using microchips with thrombogenic surfaces (collagen plus tissue factor, atheroma [AR]-chip), is validated and can evaluate the total thrombogenicity.

Purpose

To investigate the utility of T-TAS parameters in predicting TLR after EVT in CLI patients.

Methods

We analyzed 27 CLI patients (45 lesions; aortoiliac 20%, femoropopliteal 40%, infrapopliteal 40%) who underwent EVT at our institution between January 2018 and December 2020. Patients undergoing hemodialysis were excluded. Blood sample was collected on the day of EVT and was used in T-TAS to compute the thrombus formation area under the curve (AUC; AUC for the first 30 minutes for AR tested at flow rate of 10 lL/min [AR10-AUC30]). We investigated the relationship between the AR10-AUC30 level and the occurrence of clinically-driven TLR, and the predictors of TLR among CLI patients.

Results

Study population had a mean age of 77 years, and 56% were male. During the follow-up period (mean 1.0±0.7 years), 11 lesions (24%) required clinically-driven TLR. The AR10-AUC30 level was significantly higher in patients requiring TLR than those without TLR (1783±121 vs. 1587±205; p<0.01). The frequency of TLR significantly increased in association with a tertile of the AR10-AUC30 level (Figure 1, p for trend=0.003). As shown in Figure 2, univariate logistic regression analysis demonstrated male sex and the third tertile of the AR10-AUC30 level compared to its first or second tertiles were significantly associated with TLR in patients with CLI, whereas platelet count, PT-INR, APTT, and atherosclerotic risk factors including glycated hemoglobin, low-density lipoprotein cholesterol, and renal function were not. Multivariate logistic regression analysis also revealed that the AR10-AUC30 level ≥1707 (=its third tertile) as an independent predictor for TLR, even after adjusted by age and sex (OR=6.28, 95% CI=1.18–33.3, p=0.03).

Conclusions

In patients with CLI, the AR10-AUC30 level measured by the T-TAS may be a potential predictor to identify the high-risk patients requiring TLR after EVT. This finding suggests the hypercoagulability in CLI patients and that an anticoagulant agent following EVT may be useful in preventing a restenosis in CLI patients. Further study with a larger sample size is warranted to validate this finding.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Cavin-1 modulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

Background

Pulmonary hypertension (PH) is a progressive disease associated with poor outcomes. Caveolin-1 (Cav1) and Cavin-1 are components of caveolae, and Cav1 is identified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is the most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known.

Purpose

Our study aims to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway in pulmonary artery endothelial cells (PAECs). [Methods] Cav1 knockout mice were used to assess PH, and caveolae in PAECs were observed by electron microscope. After knocking down Cav1 and/or Cavin-1 in human PAECs (hPAECs) using siRNA, we evaluated the phosphorylation of Smad by Western blotting. Apoptosis was explored by flow cytometry. To assess the interaction between Cav1 and BMPRII, and the effect of Cavin-1 for this interaction and BMP/Smad signaling, we performed immunoprecipitation, Co-immunostaining, Proximal Ligation Assay (PLA), GST pulldown assay, and Western blotting.

Results

As in previous reports, Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy and PAECs isolated from Cav1 knockout mice showed caveolae disappearance. Cav1 knockdown in hPAECs reduced BMPRII at the plasma membrane and Smad 1/5/9 phosphorylation. Cav1 knockdown also significantly increased hypoxia-induced apoptosis in hPAECs. Co-immunostaining revealed that Cav1 was associated with BMPRII at the membrane of hPAECs. Cavin-1 inhibited the interaction of BMPRII with Cav1 and reduced BMPRII localization on the membrane of hPAECs. GST pulldown assay revealed that Cavin-1 and BMPRII were associated with Cav1 through the scaffolding domain in Cav1. These findings suggest that Cavin-1 and BMPRII are competitively associated with Cav1. Cavin-1 knockdown improved the interaction between Cav1 and BMPRII and inhibited both BMPRII reduction at the plasma membrane and Smad 1/5/9 dephosphorylation.

Conclusions

Cavin-1 affects the interaction of Cav1 with BMPRII at the plasma membrane and modulates BMP/Smad signaling in PAECs. The binding of Cavin-1 to Cav1 enhances the interaction between BMPR2 and Cav1, resulting in stabilization of BMPRII localization at the plasma membrane in PAECs and prevention of BMP/Smad signaling attenuation, which is important for PAH development.

Funding Acknowledgement

Type of funding sources: None.

Cavin-1 regulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

Background

Pulmonary hypertension (PH) is a progressive disease associated with poor outcome. Caveolin-1 (Cav1) is a component of caveolae and classified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is a most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known.

Purpose

The aim of our study is to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway and explore the mechanism of downstream signal transduction of BMP signaling by the interaction between Caveolin and BMPRII.

Methods

Cav1 knockout mice were used to assess PH and caveolae in pulmonary artery endothelial cells were observed by electron microscope. Cav1 and Cavin-1, which is a component of caveolae and form a complex with Cav1, were knocked-down in human pulmonary artery endothelial cell (hPAEC) using siRNA and phosphorylation of Smad signal was evaluated. Apoptosis of these cells was explored by flow cytometry. We investigated the interaction between Cav1 and BMPRII, and evaluated whether Cavin-1 affects this interaction and signal transduction of BMP signaling.

Results

As previously described, deletion of Cav1 revealed disappearance of caveolae in pulmonary artery endothelial cells (PAECs), and Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy. We then examined roles of Cav1 in human PAECs (hPAECs). Cav1 knockdown in hPAECs reduced phosphorylation of Smad 1/5/9. In addition, Cav1 knockdown significantly increased hypoxia-induced apoptosis in hPAEC. Knockdown of Cavin-1 reversed phosphorylation of Smad 1/5/9 decreased by Cav1 knockdown in BMP9 stimulation. Cavin-1 reversed the expression of BMPRII decreased by overexpression of Cav1. Cav1 was associated with Cavin-1 at the plasma membrane in PAECs. Cav1 also associated with BMPRII at the membrane of hPAECs that was inhibited by Cavin-1, and Cavin-1 reduced the localization of BMPRII to the membrane of hPAECs. These results suggest that BMPRII interacts with Cav1 via Cavin-1-associated localization at the plasma membrane in hPAECs, resulting in regulating BMP/Smad signaling pathway and involving in the development of PAH.

Conclusions

Cavin-1 affects the interaction of Cav1 with BMPRII at the membrane of PAECs, and regulates BMP/Smad signaling. These results reveal a previously undescribed function of Cavin-Caveolin system in the development of PAH through regulation of BMP/Smad signaling.

Funding Acknowledgement

Type of funding source: None

SDPR/Cavin-2 loss inhibits monocyte adhesion to endothelial cells in abdominal aortic aneurysm via suppressing the expression of adhesion molecules

Background

Abdominal aortic aneurysm (AAA) is a common and life-threatening vascular disease. The initial phase of AAA progression is vascular inflammation. Inflammation sites present adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1). These molecules play a crucial role in recruiting inflammatory cells to endothelial cells through NF-κB signaling. Endothelial cells express serum deprivation response (SDPR)/Cavin-2 localized in caveolae on the cell membrane. Although Cavin-2 is involved in such as cell proliferation, migration, and signal transduction, the role of Cavin-2 in vascular inflammation in the development of AAA is still unclear.

Purpose

To assess the influence of Cavin-2 deficiency in AAA development and clarify the role of Cavin-2 in the regulation of inflammatory cell adhesion in endothelial cells.

Methods

CaCl2-induced AAAs were induced by the periaortic application of 0.5 M CaCl2 in male SDPR-knockout (KO) and wild-type (WT) mice at 8–10 weeks of age. Angiotensin II (Ang II)-induced AAAs were created by 4-week-subcutaneous drug infusion in male ApoE-KO and ApoE/Cavin-2-double KO (DKO) mice at 24 weeks of age. Inflammatory response and cell adhesion were evaluated using human aortic endothelial cells (HAECs) and human monocytes (THP-1 cells).

Results

Six weeks after CaCl2 treatment, Cavin-2 deficiency significantly attenuated the development of AAAs. Elastin degradation was markedly suppressed and F4/80-positive macrophages infiltration in aortic walls were decreased in Cavin-2-KO mice. Although Ang II infusion for 4 weeks formed AAAs in ApoE KO mice and ApoE/Cavin-2-DKO mice, ApoE/Cavin-2-DKO mice exhibited the suppression of AAA formation independently of blood pressure. Immunohistochemical staining showed VCAM-1 expression on endothelial cells was suppressed in ApoE/Cavin-2-DKO mice. Further, in vitro co-culture experiment, the number of THP-1 cells adhered to TNF-treated SDPR-knockdown HAECs was decreased compared with that to control HAECs. Moreover, mRNA expression of VCAM-1 and ICAM-1 was decreased in TNFα-treated SDPR-knockdown HAECSs. Protein expression of VCAM-1 was also suppressed in TNFα-treated SDPR-knockdown HAECSs. The activity of NF-κB p65, an upstream regulator of VCAM-1 and ICAM-1,tended to be suppressed in TNFα-treated SDPR-knockdown HAECs.

Conclusion

In this study, we revealed that SDPR/Cavin-2 loss attenuated AAA development with the suppression of elastin degradation and macrophage infiltration. Our findings suggest that SDPR/Cavin-2 in the endothelial cells regulates the expression of adhesion molecules via NF-κB signaling and promotes the adhesion and infiltration of inflammatory cells to the aortic wall.

Funding Acknowledgement

Type of funding source: None

The efficacy of a PCSK9 inhibitor for the plaque stabilization in the non-culprit lesion of ACS patients by using near-infrared intravascular ultrasonography

Background and purpose

In acute coronary syndrome (ACS) patients, major cardiovascular events during follow-up were equally attributable to recurrence at the site of culprit lesions and to non-culprit lesions, and mostly occurred within one year. Recent studies showed that Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitor significantly reduces the risk of cardiovascular events. However, the rigorous effects of PCSK9 inhibitor in patients with ACS, especially for the stabilization of plaque in the non-culprit lesions has not been identified. The purpose of this study was to evaluate the efficacy of a PCSK9 inhibitor for the plaque stabilization in the non-culprit lesion of ACS patients.

Methods

We retrospectively analyzed the 10 ACS patients (STEMI:5 cases, NSTEMI:1 case, and UAP:4 cases) who had non-culprit lesions and were injected with a PCSK9 inhibitor. We analyzed 11 non-culprit lesions before and after PSCK9 injections by using a near-infrared intravascular ultrasonography (NIRS-IVUS).

Results

The follow up intervals were 229.4±82.9 days. Major cardiovascular events did not occur in all patients. The serum low-density lipoprotein (LDL) cholesterol levels were significantly decreased form 128±36.7 mg/dl to 26.7±7.4 mg/dl (P<0.01; Figure 1A). There were no significant changes in percent atheroma volume before and after PCSK9 injections. However, the max lipid core burden index (LCBI) were significantly improved from 392.5±155.8 to 209.4±116 (P<0.01; Figure 1B). Although the lesion characteristics did not change in the images, by IVUS, the LCBI of the lesion was significantly decreased after PCSK9 injections. This study suggested that NIRS-IVUS had the possibility of detection for the slight changes in the plaque characteristics, which could not be detected by only an IVUS.

Conclusion

This study suggested that the plaque morphology can be altered by the aggressive lipid lowering therapy by using a PCSK9 inhibitor, and NIRS-IVUS can detect these plaque stabilizations of non-culprit lesion in ACS patients.

The authors have no financial conflicts of interest to disclose concerning the presentation.

Figure 1

Funding Acknowledgement

Type of funding source: None

The usefulness of total thrombus-formation analysis system for predicting high bleeding risk in coronary artery disease patients taking anticoagulants who underwent percutaneous coronary intervention

Background

Although anticoagulants are widely used for prevention of cerebral infarction in patients with atrial fibrillation (AF), venous thrombosis, and valvular disease, it is possible that anticoagulants increase bleeding events in daily medical practices. Recently, we reported that the total thrombus-formation analysis system (T-TAS) was useful for evaluating bleeding risk in coronary artery disease (CAD) patients.

Aim

We examined whether T-TAS was practical for predicting bleeding risk in CAD patients taking anticoagulants who underwent percutaneous coronary intervention (PCI).

Methods

This study was the retrospective analysis of the 500 consecutive CAD patients who underwent PCI. Blood samples obtained on the day of PCI were used in T-TAS to compute the thrombus formation area under the curve (AUC) (AR10-AUC30, AUC for AR chip). We divided the total number of study patients into two groups according to the presence of anticoagulants; 53 CAD patients with triple therapy (TT) and 447 CAD patients with dual antiplatelet therapy (DAPT). We compared clinical characteristics and prognosis between the two groups. The primary endpoint was 1-year bleeding events that were defined by ISTH bleeding criteria. We excluded the CAD patients who underwent emergency PCI, and who were treated for hemodialysis.

Results

All patients took aspirin and clopidogrel, or aspirin and prasugrel at baseline. Compared to the patients with DAPT, the patients with TT had atrial fibrillation and history of stroke. The AR10-AUC30 levels were significantly lower in the patients with TT than the patients with DAPT (median [interquartile range] 1402.6 [1095.1–1609.8] vs. 1679.8 [1526.4–1783.3], p<0.001). Thirty-five patients (7%) had bleeding events during follow-up [11 cases (20.8%) in the patients with TT, 24 cases (5.4%) in the patients with DAPT]. Kaplan-Meier curve analysis showed a worse 1-year bleeding event-free survival rate in the patients with TT compared with the patients with DAPT (p<0.001). Receiver operating characteristic analysis showed that AR10-AUC30 levels significantly predicted bleeding events (AUC 0.653, 95% CI 0.555–0.751; p=0.003) and the cut-off point was 1586.4 by Youden index in the present study. In multivariate Cox hazards analysis, low AR10-AUC30 level (≤1586.4) (hazard ratio 2.99; 95% CI 1.46–6.11; p=0.003) and taking warfarin (hazard ratio 3.02; 95% CI 1.24–7.34; p=0.015) were significant predictors for 1-year bleeding events.

Conclusions

The present findings suggested that the AR10-AUC30 level determined by T-TAS could be a useful marker for predicting high bleeding risk in CAD patients taking anticoagulants who underwent PCI.

Funding Acknowledgement

Type of funding source: None

Selexipag for Chronic Thromboembolic Pulmonary Hypertension in Japanese Patients - A Double-Blind, Randomized, Placebo-Controlled, Multicenter Phase II Study

BACKGROUND

Selexipag is an oral prostacyclin receptor (IP receptor) agonist with a non-prostanoid structure. This study examined its efficacy and safety in Japanese patients with non-operated or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH).Methods and Results:This Phase II study was a randomized, double-blind, placebo-controlled parallel-group comparison. The primary endpoint was a change in pulmonary vascular resistance (PVR) from baseline to week 17. The main analysis involved a per-protocol set group of 28 subjects. The change in PVR (mean±SD) after 17 weeks of treatment in the selexipag group was -104±191 dyn·s/cm⁵, whereas that in the placebo group was 26±180 dyn·s/cm⁵. Thus, the treatment effect after 17 weeks of selexipag treatment was calculated as -130±189 dyn·s/cm⁵(P=0.1553). Although the primary endpoint was not met, for the group not concomitantly using a pulmonary vasodilator the PVR in the selexipag group was significantly decreased compared with placebo group (P=0.0364). The selexipag group also showed improvement in total pulmonary resistance and cardiac index.

CONCLUSIONS

Selexipag treatment improved pulmonary hemodynamics in Japanese patients with CTEPH, but PVR did not show a significant difference between the selexipag and placebo groups. (Trial registration: JAPIC Clinical Trials Information [JapicCTI-111667]).

Long-term treatment of pulmonary arterial hypertension with macitentan in Japanese patients

Objective: Macitentan, a novel dual endothelin receptor antagonist, was approved for the treatment of pulmonary arterial hypertension (PAH) in Japan. However, long-term effects in Japanese patients of macitentan are currently unavailable. This study sought to assess the long-term efficacy and safety of macitentan in Japanese patients with PAH.Methods: In this multicenter, open-label, clinical extension study (JapicCTI-121986), efficacy was evaluated based on the change from baseline at 24, 48, 72, 96 and 120-week in the 6-minute walk distance (6MWD), World Health Organization (WHO) functional class, and serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels. In addition, the time to a hospitalization related to PAH and a morbidity/mortality event was determined. As for safety, the incidence of adverse events and changes in laboratory data and vital signs were assessed.Results: Macitentan was administered at a once-daily dose of 10 mg in 30 PAH patients with a median treatment period of 2.4 years (range, 229-1037 days). The improvements in 6MWD, WHO functional class and NT-pro-BNP at week 24 were maintained throughout the long-term follow-up. Hospitalization related to PAH occurred in 2 patients. Levels of liver enzyme and hemoglobin remained unchanged throughout the study period.Conclusions: This study suggests that the long-term use of macitentan is well tolerated and effective in Japanese patients with PAH. We concluded that macitentan can be a possible approach to reduce morbidity/mortality in Japanese PAH patients.

P2563Effects of rivaroxaban on cardiac remodeling after experimental myocardial infarction in mice

Background

Rivaroxaban, a direct activated factor X (FXa) inhibitor, has been established for prevention and treatment of arterial and venous thrombosis. Although FXa plays an important role in thrombosis, FXa also involves in inflammation via the protease-activated receptor (PAR)-1 and PAR-2 pathway. We assessed the hypothesis that rivaroxaban might protect cardiac remodeling after myocardial infarction (MI) in mice.

Methods

MI was induced in wild-type mice by permanent ligation of the left anterior descending coronary artery. At 1 day after MI, mice were randomly assigned to the rivaroxaban and vehicle groups. In the rivaroxaban group, the mice were provided with regular chow diet including rivaroxaban (2400ppm) after the randomization. We evaluated the cardiac function by echocardiography, expression of mRNA and protein in the infarcted and non-infarcted area 7 days after MI. Furthermore, we measured infarct size, infiltration of inflammatory cells by pathological analysis 7 days after MI.

Results

The fractional shortening (%FS) and Interventricular Septal thickness in diastole (IVSTd) was significantly improved 7 days after MI in the rivaroxaban group compared with the vehicle group (%FS, p=0.01; IVSTd, p=0.013). As for pathological analysis, rivaroxaban decreased infarct size (p=0.026) and the number of infiltrated macrophages in the non-infarcted area (p=0.011) compared with vehicle. The mRNA expression in tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β in the infarcted area and atrial natriuretic peptide (ANP) in the non-infarcted area was significantly lower in the rivaroxaban group compared with the vehicle (TNF-α, p=0.015; TGF-β, p=0.019; ANP, p=0.012). PAR-1 and PAR-2 mRNA expression in the infarcted area significantly decreased 7 days after MI in the rivaroxaban group compared with the vehicle (PAR-1, p=0.005; PAR-2, p=0.037). Furthermore, western blot analysis demonstrated that the phosphorylation of Extracellular Signal-regulated Kinase (ERK) and c-Jun N-terminal Kinase (JNK) in the non-infarcted area significantly decreased 7 days after MI in the rivaroxaban group compared with the vehicle (ERK, p=0.015; JNK, p=0.002).

Conclusions

The present study showed that rivaroxaban protected against cardiac dysfunction, probably due to the suppression of PAR-mediated increase of pro-inflammatory cytokines post-MI. Rivaroxaban might be potentially effective for improving the cardiac remodeling after MI.

Acknowledgement/Funding

This study was supported in part by trust-research grant from Bayer Yakuhin, Ltd.

Maternal and fetal outcomes in pregnancy complicated with Eisenmenger syndrome

OBJECTIVE

The goal of the study was to clarify the risk factors for pregnancy complicated with Eisenmenger syndrome (ES).

MATERIALS AND METHODS

A retrospective study was performed in 15 patients with ES who were managed throughout pregnancy at one institution from 1982 to 2013. Cases associated with congenital heart diseases other than atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) were excluded.

RESULTS

The congenital heart diseases in ES included ASD (n = 3), VSD (n = 9), and PDA (n = 3). Ten women chose termination and 5 continued with their pregnancies. In the 5 continuation cases (PDA 1, VSD 4), worsening of cyanosis, exertional fatigue and dyspnea appeared between 25 and 30 weeks gestation and cesarean section was performed at 30 (28-33) weeks. LVEF, PaO₂, and SpO₂ decreased and heart rate increased significantly from before pregnancy to 25-30 weeks gestation. From before to during the pregnancy, there were no significant changes in mean PABP or pulmonary vascular resistance (PVR) in four cases with data (582-592, 885 to 868, 1280 to 1291, 1476-1522 dyn × s/cm²). PVR at conception had a negative relationship with delivery weeks. NYHA classes before, during and 1 year after pregnancy were II, III and II. In one recent case, epoprostenol and tadalafil were administered during pregnancy.

CONCLUSIONS

Pregnancy with ES has a high risk due to hypooxygenation, cyanosis, and cardiac failure, which can appear as common complications as early as the 2nd trimester. Early interventions with meticulous care are required for these complications during pregnancy and delivery.

Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension: A systematic review

BACKGROUND

Balloon pulmonary angioplasty (BPA) has been performed for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or residual pulmonary hypertension after pulmonary endarterectomy (PEA). We performed a systematic review to assess the efficacy and safety of BPA, especially compared to medical treatment or PEA.

METHODS

We reviewed all studies investigating pre- and post-treatment pulmonary hemodynamics, mortality, or complications from three electronic databases (PubMed, Cochrane Library, Japan Medical Abstracts Society) prior to February 2017. From 26 studies retrieved, we selected 13 studies (493 patients): the 10 most recent ones including complete data from each institution, one study of residual pulmonary hypertension, and two studies comparing BPA with medical treatment or PEA.

RESULTS

No randomized controlled or prospective controlled studies comparing BPA with medical treatment or PEA were reported. The early mortality of BPA ranged from 0% to 14.3%; lung injury occurred in 7.0% to 31.4% (average sessions, 2.5-6.6). Mean pulmonary arterial pressure decreased from 39.4-56 to 20.9-36 mm Hg, and the 6-min walk distance increased from 191-405 to 359-501 m. The 2-year mortality of 80 patients undergoing BPA was significantly lower compared to 68 patients receiving medical treatment (1.3% vs. 13.2%); the risk ratio was 0.14 (95% confidence interval: 0.03-0.76). No significant difference was observed in the 2-year mortality between BPA (n=97) and PEA (n=63) patients.

CONCLUSIONS

This systematic review suggests that BPA improves hemodynamics, has acceptable early mortality, and may improve long-term survival compared with medical treatment in inoperable CTEPH patients.

The Efficacy of a Genetic Analysis of the BMPR2 Gene in a Patient with Severe Pulmonary Arterial Hypertension and an Atrial Septal Defect Treated with Bilateral Lung Transplantation

Severe pulmonary arterial hypertension (PAH) rarely develops in children with an atrial septal defect (ASD), even those with a large defect. We herein report the case of a 27-year-old man with a moderate-sized secundum ASD and right ventricular failure due to severe PAH, which developed in his early teens. He was diagnosed as having a genetic mutation of the bone morphogenetic protein receptor-2 (BMPR2) gene and was successfully treated with bilateral lung transplantation with ASD path closure. In patients with congenital heart disease, a genetic analysis may provide information about the lifetime risk of developing PAH.

Left main coronary artery compression by a dilated main pulmonary artery and left coronary sinus of Valsalva aneurysm in a patient with heritable pulmonary arterial hypertension and FLNA mutation

Left main coronary artery (LMCA) disease due to external compression by a dilated main pulmonary artery (MPA) is an uncommon clinical entity. Here, we describe a 52-year-old woman with pulmonary arterial hypertension (PAH) and anteroseptal old myocardial infarction (OMI). The cause of the OMI was external compression of the LMCA by the dilated MPA and aneurysm of the left coronary sinus of Valsalva. The patient’s sister (aged 56 years) had also been diagnosed with PAH and both women had a novel heterozygous splicing mutation, IVS2-2A > G (c.374-2A > G in NM_001456), in the filamin A (FLNA) gene. To our knowledge, this is the first report of HPAH which is likely to be due to FLNA mutation and compression of the LMCA between a dilated MPA and aneurysm of the left coronary sinus of Valsalva.

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.

Efficacy of cardiac rehabilitation after balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

Objective

To determine safety and efficacy of cardiac rehabilitation (CR) initiated immediately following balloon pulmonary angioplasty (BPA) in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) who presented with continuing exercise intolerance and symptoms on effort even after a course of BPA; 2–8 sessions/patient.

Methods

Forty-one consecutive patients with inoperable CTEPH who underwent their final BPA with improved resting mean pulmonary arterial pressure of 24.7±5.5 mm Hg and who suffered remaining exercise intolerance were prospectively studied. Participants were divided into two groups just after the final BPA (6.8±2.3 days): patients with (CR group, n=17) or without (non-CR group, n=24) participation in a 12-week CR of 1-week inhospital training followed by an 11-week outpatient programme. Cardiopulmonary exercise testing, haemodynamics, and quality of life (QOL) were assessed before and after CR.

Results

No significant between-group differences were found for any baseline characteristics. At week 12, peak oxygen uptake (VO₂), per cent predicted peak VO₂ (70.7±9.4% to 78.2±12.8%, p<0.01), peak workload, and oxygen pulse significantly improved in the CR group compared with the non-CR group, with a tendency towards improvement in mental health-related QOL. Quadriceps strength and heart failure (HF) symptoms (WHO functional class, 2.2–1.8, p=0.01) significantly improved within the CR group. During the CR, no patient experienced adverse events or deterioration of right-sided HF or haemodynamics as confirmed via catheterisation.

Conclusions

The combination of BPA and subsequent CR is a new treatment strategy for inoperable CTEPH to improve exercise capacity to near-normal levels and HF symptoms, with a good safety profile.

Efficacy and Safety of a Novel Endothelin Receptor Antagonist, Macitentan, in Japanese Patients With Pulmonary Arterial Hypertension

BACKGROUND

Macitentan is a novel, dual endothelin receptor antagonist with sustained receptor binding, used for the long-term treatment of pulmonary arterial hypertension (PAH). In the present study, we assessed the efficacy and safety of macitentan in Japanese patients with PAH.

METHODS AND RESULTS

Macitentan was administered at a once-daily dose of 10 mg in 30 patients. The primary endpoint was change in pulmonary vascular resistance (PVR) from baseline to week 24. Change to week 24 in the other hemodynamic parameters, 6-min walk distance (6MWD), World Health Organization (WHO) functional class, and plasmaN-terminal pro-brain natriuretic peptide (NT-pro-BNP), as well as time to clinical deterioration up to week 52 were also assessed as secondary endpoints. In the 28 patients on per-protocol analysis, PVR decreased from 667±293 to 417±214 dyn·sec·cm(-5)(P<0.0001). 6MWD increased from 427±128 to 494±116 m (P<0.0001). WHO functional class improved in 13 patients (46.4%) and was maintained in 15 patients (53.6%), and NT-pro-BNP was reduced by 18% (P<0.0001). The favorable treatment effect on PVR was apparent regardless of concomitant therapy for PAH.

CONCLUSIONS

Macitentan was efficacious and well tolerated and improved the hemodynamic parameters, exercise capacity, symptoms, and clinical biomarkers in Japanese PAH patients. Macitentan can be a valuable therapeutic option for Japanese patients with PAH. (

TRIAL REGISTRATION

JAPIC Clinical Trials Information [JapicCTI-121986].) (Circ J 2016; 80: 1478-1483).

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.

Successful balloon pulmonary angioplasty with gadolinium contrast media for a patient with chronic thromboembolic pulmonary hypertension and iodine allergy

A 28-year-old male was referred to our hospital with dyspnea. He was diagnosed as having chronic thromboembolic pulmonary hypertension, and a pulmonary endarterectomy (PEA) was performed. However, exertional dyspnea remained because of residual pulmonary hypertension; therefore, the patient was re-admitted to our hospital 1 year after PEA. We performed computed tomography and pulmonary angiography and found web and band lesions in the distal pulmonary artery with a high pulmonary artery pressure. Although further management was complicated because the patient had an anaphylactic shock to iodine-based contrast media, we eventually completed five sessions of balloon pulmonary angioplasty (BPA) using gadolinium contrast medium. His symptoms and hemodynamics dramatically improved after a series of BPA. After 15 months, mean pulmonary arterial pressure reduced from 67 mmHg to 20 mmHg, and subjective symptoms improved from stage Ⅳ to I as per the WHO classification system. BPA is a potential procedure for residual pulmonary hypertension after PEA and could be safely performed using gadolinium contrast medium for patients with iodine allergy.

Rescue balloon pulmonary angioplasty in a rapidly deteriorating chronic thromboembolic pulmonary hypertension patient with liver failure and refractory infection

Pulmonary endarterectomy (PEA) is the standard therapy for chronic thromboembolic pulmonary hypertension (CTEPH). Balloon pulmonary angioplasty (BPA) is an alternative therapy for such patients. Here we report the case of a 60-year-old woman who presented with severe CTEPH resulting in low cardiac output and liver failure. Her clinical status rapidly deteriorated after she developed a respiratory infection that was refractory to antibiotic treatment. PEA was risky because of her unstable hemodynamics, uncontrolled infection, and liver failure with jaundice. We thus performed rescue BPA. After 3 BPA procedures, her cardiac symptoms improved from World Health Organization functional class IV to II, and her jaundice resolved. The day after her final BPA procedure, her hemodynamics dramatically improved, and she continued to show improvement 3 months later. We thus suggest that BPA is a good treatment option in CTEPH patients with rapidly deteriorating heart failure and uncontrolled comorbidities.

Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but debilitating and life-threatening complication of acute pulmonary embolism. CTEPH results from persistent obstruction of pulmonary arteries and progressive vascular remodelling. Not all patients presenting with CTEPH have a history of clinically overt pulmonary embolism. The diagnostic work-up to detect or rule out CTEPH should include ventilation-perfusion scintigraphy, which has high sensitivity and a negative predictive value of nearly 100%. CT angiography usually reveals typical features of CTEPH, including mosaic perfusion, part or complete occlusion of pulmonary arteries, and intraluminal bands and webs. Patients with suspected CTEPH should be referred to a specialist centre for right-heart catheterisation and pulmonary angiography. Surgical pulmonary endarterectomy remains the treatment of choice for CTEPH and is associated with excellent long-term results and a high probability of cure. For patients with inoperable CTEPH, various medical and interventional therapies are being developed.

BMPR2 gene mutation in pulmonary arteriovenous malformation and pulmonary hypertension: a case report

The transforming growth factor-β superfamily signaling pathway is thought to be involved in the pathogenesis of pulmonary arteriovenous malformation (PAVM). However, the association between bone morphogenetic protein receptor type 2 (BMPR2) gene mutations and PAVM remains unclear. We present a case of concurrent PAVM and pulmonary arterial hypertension (PAH), with a deletion mutation in exon 6 and exon 7 of the BMPR2 gene. Drug treatment for PAH improved the patient's hemodynamics and exercise capacity, but worsened oxygenation. This case suggests that BMPR2 gene mutation may be associated with the complex presentation of PAVM combined with PAH.

Organized thrombus in pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension; imaging with cone beam computed tomography

PURPOSE

To assess the usefulness of cone-beam CT (CBCT) during pulmonary angiography for the evaluation of organized thrombus at segmental or subsegmental arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

MATERIALS AND METHODS

The segmental and/or subsegmental pulmonary arteries of 13 patients with CTEPH were evaluated by CBCT. We classified representative forms of organized thrombus into 4 types (type 1: webs, type 2: web and slits, type 3: slits, and type 4: narrowing or complete occlusion), and the distribution and frequency of the organized thrombus were evaluated. The relative detectability of these lesions using CBCT was compared with that in contrast-enhanced CT pulmonary angiography (CTPA).

RESULTS

Type 1 lesions were most frequently observed in both segmental (30/65 = 46 %) and subsegmental branches (72/156 = 46 %). Type 2 lesions were relatively less frequent than type 1, but subsegmental branches were frequently involved (29/156 = 19 %). Type 3 lesions observed as a thin flap in 9/156 subsegmental branches (6 %). Comparing with CTPA, all 40 lesions in segmental branches were detectable in CTPA, whereas only 62 lesions among 90 lesions (69 %) in subsegmental branches could be observed by CTPA.

CONCLUSION

CBCT is found to be useful for the treatment planning of balloon pulmonary angioplasty distal to segmental arteries.

Right ventricular reverse remodelling after balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has been reported to improve haemodynamics and functional capacity, with an acceptable risk, in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not candidates for pulmonary endarterectomy. However, right ventricular (RV) function, an important predictor in CTEPH, remains to be elucidated. We aimed to examine the impact of BPA on RV remodelling and dysfunction relative to haemodynamic improvements in patients with inoperable CTEPH. 20 consecutive patients with inoperable CTEPH who underwent BPA with cardiovascular magnetic resonance before and after BPA were retrospectively studied. BPA led to significant amelioration of the mean pulmonary arterial pressure, cardiac index and pulmonary vascular resistance (PVR), without death or major complications. Furthermore, BPA significantly ameliorated right-sided heart failure symptoms and signs, and exercise capacity. Cardiovascular magnetic resonance revealed a marked improvement in RV end-diastolic and end-systolic volume index, with concomitant improvements in RV ejection fraction, mass and interventricular septal bowing after BPA. Changes in RV volumes strongly correlated with changes in cardiac index and PVR. BPA induced RV reverse remodelling and improved systolic dysfunction safely by ameliorating haemodynamics in patients with inoperable CTEPH. Evaluating RV function with cardiovascular magnetic resonance may be effective for noninvasively monitoring BPA efficacy.

Risk factors of acute pulmonary thromboembolism in Japanese patients hospitalized for medical illness: results of a multicenter registry in the Japanese society of pulmonary embolism research

BACKGROUND

Although the prophylaxis of acute pulmonary thromboembolism (APTE) in hospitalized patients has been improving in Japan, there is no report concerning APTE of Japanese medical patients. Therefore, the present study was designed to investigate the characteristics of APTE in Japanese patients hospitalized for medical illness, through a retrospective study.

METHODS

In a total of 1,438 registry patients with pulmonary thromboembolism for recent 10 years, 1,027 patients with APTE were analyzed with respect to underlying diseases or predisposing factors, and clinical course.

RESULTS

A hundred thirty three patients hospitalized for medical illness developed APTE, among 433 in-hospital APTE patients. The prevalence of APTE in women was more than in men. The mean age of the patients at diagnosis was 61 +/- 17 years. Main risk factors were a prolonged immobilization, stroke, cancer, indwelling central venous catheter. Fifty-four patients had 3 or more risk factors. In-hospital mortality rate was 23%.

CONCLUSIONS

Japanese patients in this registry had almost the same findings as in western patients, except for some points that had the possibility of demonstrating a difference between westerners and Japanese in the development of APTE. Our results will be available for establishing the prevention of APTE in medical patients in Japan.

Pulmonary arterial hypertension as the first manifestation in a patient with hereditary hemorrhagic telangiectasia

A 17-year-old Japanese girl visited our hospital for an evaluation of exertional dyspnea. A diagnosis of pulmonary arterial hypertension (PAH) was confirmed based on the findings of right heart catheterization. Detailed questioning revealed a family history of hereditary hemorrhagic telangiectasia (HHT), and a genetic mutation analysis disclosed a mutation in the activin receptor-like kinase 1 gene (ACVRL1). The patient was finally diagnosed with HHT according to the Curaçao diagnostic criteria eight years after the diagnosis of PAH. This case supports previous reports indicating that signs of PAH can be the first manifestation of disease in ACVRL1 mutation carriers.

Survey of reoperation indications in tetralogy of fallot in Japan

BACKGROUND

Although the survival rate for repaired Tetralogy of Fallot (TOF) is dramatically improving, anatomical and functional residua and sequelae followed by arrhythmias and sudden death are still challenging issues to be resolved. Reoperation can reduce the incidence of arrhythmias and sudden death, but there is no consensus on the indications of reoperation for patients with TOF, especially in Japan.

METHODS AND RESULTS

A cross-sectional questionnaire survey of reoperation indications in patients with TOF was performed through a Japanese multicenter study. The questionnaire, which focused on the number of repaired TOF patients aged >15 years old, reoperation indications and management, was sent to the institutions belonging to Japanese Society for Adult Congenital Heart Disease. In total, 41.5% (78/188) of the institutions replied. The total number of repaired TOF patients was 4,010, and sudden cardiac death was observed in 45.236/4,010 (5.9%) experienced reoperation. Pulmonary stenosis (32%) and pulmonary regurgitation (29%) were the most common reasons for reoperation. There were only 2 implantable cardioverter defibrillator or resynchronization therapy defibrillator implantations. The physiological/anatomical indications of reoperation differed among the hospitals.

CONCLUSIONS

Approximately 1.1% of patients suffered sudden death and 6% of repaired TOF patients had reoperation. The indications of reoperation, however, varied among the institutions. Therefore, detailed information for each case of sudden death or reoperation should be collected and analyzed in order to establish guidelines for reoperation.