Search

Purpose: This study estimated an individual's genetic liability to cardiometabolic risk factors by polygenic risk score (PRS) construction and examined whether high cardiorespiratory fitness (CRF) modifies the association between PRS and cardiometabolic risk factors., Methods: This cross-sectional study enrolled 1296 Japanese adults aged ≥40 yr. The PRS for each cardiometabolic trait (blood lipids, glucose, hypertension, and obesity) was calculated using the LDpred2 and clumping and thresholding methods. Participants were divided into low-, intermediate-, and high-PRS groups according to PRS tertiles for each trait. CRF was quantified as peak oxygen uptake (V̇O 2peak ) per kilogram body weight. Participants were divided into low-, intermediate-, and high-CRF groups according to the tertile V̇O 2peak value., Results: Linear regression analysis revealed a significant interaction between PRS for triglyceride (PRS TG ) and CRF groups on serum TG levels regardless of the PRS calculation method, and the association between PRS TG and TG levels was attenuated in the high-CRF group. Logistic regression analysis revealed a significant sub-additive interaction between LDpred2 PRS TG and CRF on the prevalence of high TG, indicating that high CRF attenuated the genetic predisposition to high TG. Furthermore, a significant sub-additive interaction between PRS for body mass index and CRF on obesity was detected regardless of the PRS calculation method. These significant interaction effects on high TG and obesity were diminished in the sensitivity analysis using V̇O 2peak per kilogram fat-free mass as the CRF index. Effects of PRSs for other cardiometabolic traits were not significantly attenuated in the high-CRF group regardless of PRS calculation methods., Conclusions: The findings of the present study suggest that individuals with high CRF overcome the genetic predisposition to high TG levels and obesity., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Sports Medicine.)

Bleeding complications have emerged as major causes of morbidity and mortality in patients with implantable left ventricular assist devices (LVAD). We hypothesized that the hemodynamics after LVAD implantation may influence the occurrence of bleeding complications after LVAD implantation. We retrospectively evaluated 78 patients who underwent continuous-flow LVAD implantation and hemodynamic ramp test after LVAD implantation between July 2017 and July 2023 at Osaka University. The bleeding complication occurred in 13 patients. The rates of freedom from bleeding complications at 1, 3, and 5 years were 94%, 85%, and 74%. Gastrointestinal bleeding, nose bleeding, and intraperitoneal hemorrhage occurred in six, three, and two patients, respectively. Preoperative average brachial-ankle pulse wave velocity (baPWV) was positively associated with bleeding complication (1,276 ± 280 vs. 1,098 ± 190 cm/s p = 0.04). In the hemodynamic ramp test, systemic vascular resistance (SVR) in patients with bleeding complications was higher than that in patients without bleeding complications (SVR: 1,359 ± 341 vs. 1,150 ± 217 dyne sec/cm5, p = 0.01). High preoperative baPWV and high SVR in the hemodynamic ramp test were significantly associated with bleeding complications after LVAD implantation. Arteriosclerosis is a risk factor for bleeding complications after LVAD implantation., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2024.)

We aimed to compare the outcomes of pediatric kidney transplantation (KT) between preemptive KT (PEKT) and non-PEKT in children aged < 6 years. Seventy-four pediatric recipients aged < 6 years who underwent KT were divided into the PEKT and non-PEKT groups. They were retrospectively evaluated for patient and graft survival, graft function, growth, and cytomegalovirus (CMV) infection. Comparison of the groups (PEKT, n = 14; non-PEKT, n = 60) revealed no significant differences between them in terms of distribution of sex, age, weight, primary disease, or population of pre-transplant CMV immunoglobulin G-positive patients. The median estimated glomerular filtration rate before KT in the PEKT and non-PEKT groups was 11.4 and 7.3 (mL/min/1.73 m2) (P < .001), respectively, and the median duration of dialysis was 2.7 years in the non-PEKT group. Graft survival at 5 years was 100% and 95% in the PEKT and non-PEKT groups, respectively (P = .634). One patient in the non-PEKT group had vascular complications, with subsequent early graft loss. Incidence of CMV infection was significantly lower in the PEKT group (P = .044). There were no significant differences in post-transplant estimated glomerular filtration rate, acute rejection, or growth. The height standard deviation score showed catch-up growth after KT in both groups. There was no significant difference in transplant outcomes in recipients aged < 6 years, with or without pre-transplant dialysis, except for the incidence of CMV infection. Therefore, PEKT in younger children should be performed aggressively by experienced multi-disciplinary teams., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: The aim of the study is to predict employees' long-term sick leave due to psychiatric disorders using the national psychological stress screening program., Methods: University employees who took long-term psychiatric sick leave in 2016-2018 were assigned as cases. Those who were present at work and matched for sex, age, and occupation type were assigned as controls. Answers in a 57-item questionnaire were analyzed by multivariable regression, and a prediction model was developed. It was validated in cases and matched controls in 2019., Results: Six items were identified as independent predictors by multivariable regression and included in a prediction model. The area under the receiver-operating characteristics curve was 0.768 (95% confidence interval: 0.723-0.813). This finding was similar to that in the validation sample., Conclusions: The performance of the prediction model was modest and the national Stress Check Program should be further refined., Competing Interests: Conflict of interest: Takashi Kawamura: None declared, October 8, 2023;, (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Occupational and Environmental Medicine.)

Few studies have focused on the clinical outcomes and risk factors of left ventricular assist device (LVAD) pump infection, and no standard treatment for LVAD pump infection has been established. Therefore, we used a therapeutic flowchart to manage LVAD pump infections. We retrospectively evaluated 220 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2021 at Osaka University, Japan. First, we performed wound debridement, negative-pressure wound therapy, antibiotic treatment, and omental flap transposition. Subsequently, we administered conservative treatment, scheduled implantable LVAD exchange, or emergent removal of the implantable LVAD and exchange for extracorporeal LVAD or percutaneous LVAD (IMPELLA). Pump infections occurred in 32 patients. The survival rates of patients with pump infections during LVAD support were 93%, 74%, and 61% at 180 days, 1 year, and 2 years after LVAD pump infection, respectively. Fifteen patients underwent successful heart transplantation. Bridge-to-bridge surgery, preoperative use of venoarterial extracorporeal membrane oxygenation or percutaneous LVAD, high lactate dehydrogenase levels, and driveline infection were significantly associated with pump infection. Our study reveals that poor preoperative condition and driveline infection were significant risk factors for LVAD pump infection., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

Fulminant myocarditis (FM) requiring temporary mechanical circulatory support (t-MCS) has a high mortality rate. Peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pump (IABP) are sometimes insufficient to induce cardiac recovery. For patients with FM refractory to VA-ECMO with IABP, we have applied a biventricular assist device (BIVAD) or Impella to unload the left ventricle and to fully support the systemic circulation. In the last 10 years, 37 refractory FM patients histologically diagnosed with myocarditis and who did not recover with VA-ECMO were treated with BIVAD (n = 19) or Impella (n = 18). No significant difference was found between the Impella and BIVAD groups in preoperative findings other than serum creatinine level. Seventeen of 18 patients in the Impella group were successfully weaned from t-MCS in 9 (6-12) days. Conversely, the temporary BIVAD was removed in 21 (11-38) days in 10 of 19 patients. Six patients died while on temporary BIVAD because of multiple organ failure and cerebral bleeding, and three patients required conversion to implantable VAD. Compared with BIVAD, left ventricular unloading with Impella could be less invasive and could promote cardiac recovery in refractory FM patients. The Impella has the potential to provide effective temporary MCS for FM patients., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

Recently, a certain volume of biopsy specimens has been required for genetic testing of tumors using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). This study aimed to verify the superiority of our newly devised EBUS-TBNA biopsy technique, the "cross-fanning technique," which combines rotation and up-down maneuvers, by comparing its harvest volume with that of other maneuvers. Using a bronchoscope simulator, ultrasonic bronchoscope, and 21-gauge puncture needle, we compared the weight of silicone biopsy specimens obtained by the following 4 procedures: Conventional maneuver; Up-down maneuver; Rotation maneuver, and; Cross-fanning technique. Each procedure was repeated 24 times in total, rotating the sequences of the maneuvers, and the operator/assistant pair to align the conditions. The means ± standard deviations of the sample volumes for each puncture technique were as follows: 2.8 ± 1.2 mg; 3.1 ± 1.6 mg; 3.7 ± 1.2 mg, and; 3.9 ± 1.2 mg. There was a significant difference between the 4 groups (P = .024). The post hoc test showed a statistically significant difference between techniques A and D (P = .019). This study showed that the cross-fanning technique might contribute to the increased volume of tissue samples obtained by EBUS-TBNA biopsy., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Competing Interests: The authors declare no conflicts of interest.

The effectiveness of thoracoscopic biopsy as a diagnostic method for pleural diseases has been reported; however, obtaining a sufficient specimen size is sometimes difficult. Therefore, an ancillary technique, the precut technique using an injection needle, was devised to address this problem. This study aimed to evaluate the effectiveness and safety of the novel precut technique in patients with undiagnosed pleural effusion. This retrospective study included 22 patients who underwent pleural biopsy using the precut technique to examine exudative pleural effusion of unknown etiology. Thoracoscopy was performed under local anesthesia. The biopsy procedure was performed as follows: a needle was inserted into the pleura around the lesion using a semiflexible thoracoscope; the needle was positioned to make an incision in the pleura while injecting 1% lidocaine with epinephrine and lifting the pleura from the fascia; 2 or 3 precut incision lines were arranged in a triangle; and the specimen was obtained from the parietal pleura using forceps or a cryoprobe. Patient data including age, number of biopsies, biopsy specimen size, pathological and final diagnosis, and postoperative complications were examined. All patients were male with an average age of 74 years. Pleural effusion was found on the right and left sides in 16 and 6 patients, respectively. The average major axis of the biopsy specimens was 18 mm (range, 10-30 mm), which was sufficient to establish a pathological diagnosis. Only 1 patient experienced minor temporal bleeding as a complication. The precut technique enabled the procurement of specimens sufficient in size for pleural biopsy., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Abstract: Virtual automatic bronchoscopic navigation (VBN) systems to determine the route to peripheral pulmonary lesions (PPLs) in lung cancer can improve diagnostic biopsy yields. However, compared with VBN, drawing manual routes using computed tomography images, especially with oblique methods, can identify more routes. The Ziostation2 VBN system combines the benefits of these 2 methods; we evaluated this performance by comparing 3 different route-determining methods.We retrospectively collected data from 50 patients with PPLs measuring <30 mm who underwent transbronchial biopsy with an ultrathin bronchoscope at the Osaka International Cancer Institute during January to December 2018. We compared automatic VBN (Ziostation2), manual route modification using an oblique method after automatic VBN, and manual navigation using a general application computed tomography viewer. Concordance between predicted and actual branching were determined. We also compared the predicted relationship between the terminal bronchi and the lesion by 2 of the methods with ultrasonographic images (radial-probe endobronchial ultrasonography [radial-EBUS]).Manual modification after automatic VBN significantly increased the rate of determining routes to the target (66%) versus with the automatic VBN alone (32%) (P < .001). Expected route bifurcations were exact matches with actual branching in 45/48 of the patients using manual modification after automatic VBN. The predicted relationship between the terminal bronchi and the lesion using manual modification after VBN matched the radial-EBUS images in 35/50 of the patients.Manual modification of routes to PPLs using an oblique method after automatic VBN predicted actual radial-EBUS route imaging and could help determine appropriate patients for bronchoscopy., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objectives: Little is known about patient safety performance under the social insurance medical fee schedule in Japan. The Health Ministry in Japan introduced the preferential patient safety countermeasure fee (PPSCF) to promote patient safety in 2006 and revised the PPSCF system in 2010. This study aims to address the patient safety performance status at hospitals implementing the PPSCF., Methods: A nationwide questionnaire survey targeting 2674 hospitals with the PPSCF was performed in 2010 to 2011. The 627 participant hospitals were divided into the following three groups: 178 hospitals implementing PPSCF 1 with 400 beds or more (group A), 286 hospitals implementing PPSCF 1 with 399 beds or fewer (group B), and 163 hospitals implementing PPSCF 2 (group C)., Results: The mean numbers (standard errors) of patient safety managers were 1.45 (0.07) in group A, 1.12 (0.04) in group B, and 0.37 (0.12) in group C (P < 0.001). The participation number and rates of all staff for the patient safety seminar were 1721 (167) and 1.64 (0.10) in group A, 580 (26) and 1.94 (0.09) in group B, and 349 (31) and 1.98 (0.17) in group C (P < 0.001, P = 0.105).These results can be explained because hospitals with PPSCF 1 (groups A and B) must assign at least one full-time patient safety manager, whereas hospitals with PPSCF 2 (group C) are not required to do so. Patient safety performance at hospitals with PPSCF 1 was more active than that at hospitals with PPSCF 2. However, when the values were converted to per capita or per 100 beds, there were no differences across the three groups., Conclusions: The PPSCF encourages hospitals to perform actions for patient safety by providing incentives under the social insurance medical fee schedule in Japan., Competing Interests: The authors disclose no conflict of interest., (Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: We aimed to investigate the hypothesis that type I collagen plays a role in increasing bone mineral density (BMD) and muscle stiffness, leading to low and high risks of fatigue fracture and muscle injury, respectively, in athletes. As a potential mechanism, we focused on the effect of the type I collagen alpha 1 chain gene (COL1A1) variant associated with transcriptional activity on bone and skeletal muscle properties., Methods: The association between COL1A1 rs1107946 and fatigue fracture/muscle injury was evaluated in Japanese athletes. Effects of the polymorphism on tissue properties (BMD and muscle stiffness) and type I collagen α1/α2 chain ratios in muscles were examined in Japanese nonathletes., Results: The C-allele carrier frequency was greater in female athletes with fatigue fracture than in those without (odds ratio = 2.44, 95% confidence interval [CI] = 1.17-5.77) and lower in female athletes with muscle injury than in those without (odds ratio = 0.46, 95% CI = 0.24-0.91). Prospective validation analysis confirmed that in female athletes, muscle injury was less frequent in C-allele carriers than in AA genotype carriers (multivariable-adjusted hazard ratio = 0.27, 95% CI = 0.08-0.96). Among female nonathletes, the C-allele of rs1107946 was associated with lower BMD and lower muscle stiffness. Muscle biopsy revealed that C-allele carriers tended to have a larger type I collagen α1/α2 chain ratio than AA genotype carriers (2.24 vs 2.05, P = 0.056), suggesting a higher proportion of type I collagen α1 homotrimers., Conclusion: The COL1A1 rs1107946 polymorphism exerts antagonistic effects on fatigue fracture and muscle injury among female athletes by altering the properties of these tissues, potentially owing to increased levels of type I collagen α1 chain homotrimers., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Sports Medicine.)

Background: Atopic dermatitis (AD) is a common eczematous skin disorder that profoundly reduces the quality of life due to intractable pruritus. Excellent therapeutic success of the anti-interleukin 4 receptor-α antibody dupilumab in clinical trials and a real-world clinical context indicates the crucial roles of interleukin (IL)-4 and IL-13 in the pathogenesis of AD. Along with the clinical improvement in skin scores and pruritus, dupilumab significantly and progressively reduces and normalizes the upregulated expression of T helper type 2 signatures such as Chemokine (C-C motif) ligand (CCL)17, CCL18, CCL22, and CCL26 in the lesional skin of AD. However, no blood/serum biomarkers are known to predict good or poor outcome in patients with AD treated with dupilumab., Methods: Patients are at least 18 years of age and have moderate-to-severe AD with Eczema Area and Severity Index (EASI) ≥16, Investigator's Global Assessment ≥3, and body surface area ≥10%. We are going to enroll more than 130 subjects from 18 medical facilities. Clinical objective findings will be evaluated by EASI. Subjective symptoms will be assessed by Patient-Oriented Eczema Measure, Numerical Rating Scale for Pruritus (Pruritus-NRS), Skin Comfort-NRS, and Treatment Satisfaction-NRS. We will measure 18 blood/serum biomarkers including % eosinophils in blood cell count, lactate dehydrogenase, total IgE, soluble interleukin 2 receptor, CCL17, CCL18, CCL22, CCL26, CCL27, IL-13, IL-22, IL-24, IL-25, IL-31, IL-33, thymic stromal lymphopoietin, periostin, and squamous cell carcinoma antigen-2. The clinical evaluation and biomarker sampling will be performed at 0, 2, 4, 8, and 16 weeks of dupilumab treatment. We will also perform proteomic analysis (of roughly 300 proteins) of the patients' sera obtained at 0 and 2 weeks of treatment. The primary endpoint is the association between "baseline levels of 18 biomarkers" and "% change from baseline of EASI at 16 weeks of dupilumab treatment.", Discussion: This is the first clinical trial to explore the biomarkers, including potential proteomic markers, most strongly associated with improvement in EASI in patients with moderate-to-severe AD treated with dupilumab for 16 weeks (B-PAD study). A limitation is that we will only enroll Japanese patients.

Background: Although allogeneic-induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) exhibit potential in cardiomyogenesis for heart failure, whether major histocompatibility complex (MHC)-matched allogenic iPSC implantation (MMAI) minimizes immune rejection for cell survival or functional recovery remains unknown. We herein explored whether MMAI with an iPSC-CM sheet is stable for a longer period and therapeutically more effective than MHC-mismatched AI in a primate ischemic cardiomyopathy model., Methods: Green fluorescent protein-transfected iPSC-CM sheets, derived from cynomolgus macaques with homozygous MHC haplotypes ''HT1,'' were transplanted on the left ventricle, generated by ligating the left anterior descending artery for 2 weeks in an ischemic model with or without heterozygous HT1 as MMAI and MHC-mismatched AI. Sham models were made by opening the chest at 14 days after left anterior descending ligation without any treatment., Results: Stereomicroscopy revealed that at 4 months after transplantation, green fluorescent protein intensity was higher in the MMAI group than in the MHC-mismatched AI group and the sham group. Immunohistochemistry staining revealed that host immune reaction with CD3-positive cells was stronger in MHC-mismatched AI than in MMAI at 3 months. Cardiac function improved both in MMAI and MHC-mismatched AI at 1 month after transplantation and was preserved until 6 months, whereas in the sham group, functional deterioration progressed over time., Conclusions: Although MHC-homo-iPSCs are preferred to avoid immune rejection, MHC-mismatched iPSC-CMs can also induce comparable cardiac functional recovery at late follow-up, suggesting that MHC-mismatched iPSC-based cardiac regenerative therapy with immunosuppressants is a feasible option for treating heart failure in clinical settings.

Rationale: An association between inflammatory myopathy and malignancy has been recognized particularly in patients positive for anti-transcription intermediary factor 1γ (TIF1γ) antibody. We report a case of anti-TIF1γ antibody positive dermatomyositis (DM) associated with thymic carcinoma which radiographically mimicked benign tumor., Patient Concerns: A 72-year-old man presented typical characteristic cutaneous manifestations and proximal muscle weakness with elevated levels of myogenic enzymes. An anterior mediastinal tumor was detected by computed tomography (CT) scan and radiographically assessed to be benign with distinct borders and little enhancement., Diagnoses: DM with anti-TIF1γ antibody and thymic carcinoma., Interventions: Thymic carcinoma was completely resected by surgery. DM was induced into remission with glucocorticoid treatment., Outcomes: The serum level of myogenic enzyme remained within normal range under low-dose glucocorticoid maintenance. No evidence of carcinoma recurrence with CT scan was observed at 1-year follow up., Lessons: The present case indicated that anti-TIF1γ antibody would play a role as the "autoimmune tumor marker" in patients with inflammatory myopathy.

Introduction: We developed a new smartphone application to deliver an automated external defibrillator (AED) to out-of-hospital cardiac arrest scene. The aim of this study was to evaluate whether an AED could be delivered earlier with or without an application in a simulated randomized controlled trial., Methods: Participants, who were asked to work as bystanders, were randomly assigned to either an application group or control group and were asked to bring an AED in both groups. The bystanders in the application group sent a signal notification using the application to two responders, who were stationed within 200 meters of the arrest scene, to carry an AED. The primary outcome was the AED delivery time by either the bystander or his/her responder., Results: In total, 61 bystanders were eligible and randomized to either the application group (32) or the control group (29). The 52 with time data were available and analyzed. The AED delivery time by either the bystander or his/her responder was significantly shorter in the application group than in the control group [133.6 (44.4) seconds vs. 202.2 (122.2) seconds, P = 0.01]., Conclusions: In this simulation-based trial, AED delivery time was shortened by our newly developed smartphone application for the bystander to ask nearby responders to find and bring an AED to the cardiac arrest scene (UMIN-Clinical Trials Registry 000016506).

Rationale: Diagnostic difficulty due to overlapped clinical findings exists in cardiac sarcoidosis (CS) patients who also have coronary artery disease. Since cardiac magnetic resonance (CMR) and fluorodeoxyglucose-positron emission tomography (FDG-PET) evaluate different pathological processes, that is, fibrosis and inflammation respectively, the combination may be useful in such a case., Patient Concerns: A 77-year-old man was admitted due to heart failure and advanced atrioventricular block who was previously diagnosed with cutaneous sarcoidosis and old myocardial infarction (MI) with angiographical evidence., Diagnosis: He was finally diagnosed with CS using CMR and FDG-PET by specifying the myocardial lesion of sarcoidosis., Interventions: He was treated with corticosteroids based on the diagnosis., Outcomes: The focal high uptake on FDG-PET was improved and he had a better clinical course without further cardiac events., Lessons: Our case suggests that CMR and FDG-PET are complimentary, and the combination is useful for diagnosis of CS, particularly in cases that have previous MI.

Background: Injectable, acellular biomaterials hold promise to limit left ventricular remodeling and heart failure precipitated by infarction through bulking or stiffening the infarct region. A material with tunable properties (eg, mechanics, degradation) that can be delivered percutaneously has not yet been demonstrated. Catheter-deliverable soft hydrogels with in vivo stiffening to enhance therapeutic efficacy achieve these requirements., Methods and Results: We developed a hyaluronic acid hydrogel that uses a tandem crosslinking approach, where the first crosslinking (guest-host) enabled injection and localized retention of a soft (<1 kPa) hydrogel. A second crosslinking reaction (dual-crosslinking) stiffened the hydrogel (41.4±4.3 kPa) after injection. Posterolateral infarcts were investigated in an ovine model (n≥6 per group), with injection of saline (myocardial infarction control), guest-host hydrogels, or dual-crosslinking hydrogels. Computational (day 1), histological (1 day, 8 weeks), morphological, and functional (0, 2, and 8 weeks) outcomes were evaluated. Finite-element modeling projected myofiber stress reduction (>50%; P<0.001) with dual-crosslinking but not guest-host injection. Remodeling, assessed by infarct thickness and left ventricular volume, was mitigated by hydrogel treatment. Ejection fraction was improved, relative to myocardial infarction at 8 weeks, with dual-crosslinking (37% improvement; P=0.014) and guest-host (15% improvement; P=0.058) treatments. Percutaneous delivery via endocardial injection was investigated with fluoroscopic and echocardiographic guidance, with delivery visualized by magnetic resonance imaging., Conclusions: A percutaneous delivered hydrogel system was developed, and hydrogels with increased stiffness were found to be most effective in ameliorating left ventricular remodeling and preserving function. Ultimately, engineered systems such as these have the potential to provide effective clinical options to limit remodeling in patients after infarction., (© 2016 American Heart Association, Inc.)

Objective: The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) remains to be elucidated. Thrombin-activatable fibrinolysis inhibitor (TAFI) inhibits fibrinolysis. It remains to be elucidated whether TAFI is directly involved in the pathogenesis of CTEPH. We examined potential involvement of TAFI in the pathogenesis of CTEPH in humans., Approach and Results: We enrolled 68 consecutive patients undergoing right heart catheterization in our hospital, including those with CTEPH (n=27), those with pulmonary arterial hypertension (n=22), and controls (non-pulmonary hypertension, n=19). Whole blood clot lysis assay showed that the extent of clot remaining after 4 hours was significantly higher in CTEPH compared with pulmonary arterial hypertension or controls (41.9 versus 26.5 and 24.6%, both P<0.01). Moreover, plasma levels of TAFI were significantly higher in CTEPH than in pulmonary arterial hypertension or controls (19.4±4.2 versus 16.1±4.5 or 16.3±3.3 μg/mL, both P<0.05), which remained unchanged even after hemodynamic improvement by percutaneous transluminal pulmonary angioplasty. Furthermore, the extent of clot remaining after 4 hours was significantly improved with CPI-2KR (an inhibitor of activated TAFI) or prostaglandin E1 (an inhibitor of activation of platelets). Importantly, plasma levels of TAFI were significantly correlated with the extent of clot remaining after 4 hours. In addition, the extent of clot remaining after 4 hours was improved with an activated TAFI inhibitor., Conclusions: These results indicate that plasma levels of TAFI are elevated in patients with CTEPH and are correlated with resistance to clot lysis in those patients., (© 2016 American Heart Association, Inc.)