Clinical efficacy of tolvaptan in acute decompensated heart failure patients with severe aortic stenosis and atrial fibrillation: a sub-analysis from the LOHAS registry.

BACKGROUND: Severe aortic valve stenosis (AS) and atrial fibrillation (AF) are risk factors of hemodynamic instability in heart failure (HF) management due to low cardiac output, respectively. Therefore, the treatment of HF due to severe AS complicated with AF is anticipated to be difficult. Tolvaptan, a vasopressin V2 receptor inhibitor, is effective in controlling acute decompensated heart failure (ADHF) with hemodynamic stability. However, its clinical efficacy against ADHF caused by AS with AF remains to be determined. METHODS: Clinical information (from September 2014 to December 2017) of 59 patients diagnosed with ADHF due to severe AS (20 patients with AF; 39 patients with sinus rhythm [SR]) was obtained from the LOHAS registry. The registry collected data from seven hospitals and assessed the short-term effects of tolvaptan in patients hospitalized for ADHF with severe AS. We attempted to identify clinical differences from baseline up to 4 days, comparing patients with AF (AF group) versus those with SR (SR group). RESULTS: There were no significant differences between the groups in age (83.7 ± 4.5 vs. 85.8 ± 6.9 years, respectively; p = 0.11) and aortic valve area (0.60 [0.46-0.73] vs. 0.56 [0.37-0.70] cm2, respectively; p = 0.50). However, left atrial volume was larger (104 [85-126] vs. 87 [64-103] mL, respectively; p < 0.01), whereas stroke volume was lower (51.6 ± 14.8 vs. 59.0 ± 18.7 mL, respectively; p = 0.08) in the AF group versus the SR group. Body weight decreased daily from baseline up to day 4 in both groups (from 55.4 to 53.2 kg [p < 0.01] and from 53.5 to 51.0 kg [p < 0.01], respectively) without change in heart rate. Notably, the systolic blood pressure decreased slightly in the AF group after 2 days of treatment with tolvaptan. CONCLUSIONS: Short-term treatment with tolvaptan improved HF in patients hospitalized for severe AS, regardless of the presence of AF or SR. After achieving sufficient diuresis, a slight decrease in blood pressure was observed in the AF group, suggesting an appropriate timeframe for safe and effective use of tolvaptan.

Rationale and design of Non-antithrombotic Therapy After Transcatheter Aortic Valve Implantation (NAPT) Trial.

BACKGROUND: Despite the wide implementation of transcatheter aortic valve implantation (TAVI), the optimal antithrombotic therapy after TAVI has not been established yet. Owing to the accumulating evidence supporting the efficacy and safety of single antiplatelet therapy (SAPT) over dual antiplatelet therapy, the latest guideline recommends life-long SAPT. However, there is scarce evidence supporting SAPT compared with non-antithrombotic therapy. Given the vulnerability of patients undergoing TAVI in terms of high bleeding risk, the benefit of SAPT may be canceled out by its potential increased bleeding risk. STUDY DESIGN AND OBJECTIVES: Non-antithrombotic Therapy After Transcatheter Aortic Valve Implantation (NAPT) Trial is a prospective, randomized controlled, open-label blinded endpoint multicenter trial conducted in Japan, testing the non-inferiority of non-antithrombotic therapy compared with aspirin monotherapy in patients who underwent TAVI and had no indications for long-term oral anticoagulation therapy (OAC). Patients who successfully underwent trans-femoral TAVI for severe aortic stenosis with either balloon-expandable or self-expandable valves are eligible for inclusion. Key exclusion criteria are (i) occurrence of perioperative complications (ii) indications of taking antithrombotic drugs for other reasons; (iii) eGFR <30 ml/min/1.73 m2 or hemodialysis or peritoneal dialysis. A total of 360 patients will be randomized (1:1) to aspirin monotherapy vs. non-antithrombotic therapy. The primary outcome is a composite of all-cause mortality, myocardial infarction, stroke, and bleeding. All bleeding events based on the Valve Academic Research Consortium 3 are included as a component of the primary outcome. CONCLUSION: The NAPT trial will determine the non-inferiority of a non-antithrombotic therapy compared with aspirin monotherapy after TAVI.

Interim Report of a Japanese Phase II Trial for Cardiac Stereotactic Body Radiotherapy in Refractory Ventricular Tachycardia　- Focus on Target Determination.

Background: Cardiac radiotherapy using stereotactic body radiation therapy (SBRT) has attracted attention as a minimally invasive treatment for refractory ventricular tachycardia. However, a standardized protocol and software program for determining the irradiation target have not been established. Here, we report the first preclinical stereotactic radioregulation antiarrhythmic therapy trial in Japan, focused on the target-setting process. Methods and Results: From 2019 onwards, 3 patients (age range 60-91 years) presenting with ischemic or non-ischemic cardiomyopathy were enrolled. Two patients were extremely serious and urgent, and were followed up for 6 and 30 months. To determine the irradiation targets, we aggregated electrophysiological, structural, and functional data and reflected them in an American Heart Association 17-segment model, as per the current recommendations. However, in all 3 patients, invasive electrophysiological study, phase-contrast computed tomography, and magnetic resonance imaging could not be performed; therefore, electrophysiological and structural information was limited. As alternatives, high-resolution ambulatory electrocardiography and nuclear medicine studies were useful in assessing arrhythmic substrates; however, concerns regarding test weighting and multiple scoring remain. Risks to surrounding organs were fully taken into account. Conclusions: In patients requiring cardiac SBRT, the information needed for target planning is sometimes limited to minimally invasive tests. Although there are issues to be resolved, this is a promising option for the life-saving treatment of patients in critical situations.

Slender transradial iliac artery stenting using a 4.5 French guiding sheath.

We previously reported safety and usefulness of transradial iliac artery stenting using 6 Fr guiding sheath. However, radial artery occlusion was a major limitation of this procedure. We analyzed the safety and utility of slender transradial iliac artery stenting using a 4.5 Fr guiding sheath to prevent radial artery occlusion. We performed transradial iliac artery stenting in left radial artery, using a 4.5 Fr sheath incorporating a shaft length of 110 cm, for 34 lesions in 29 patients. Transradial intervention was attempted at the discretion of the operator. Clinical data were analyzed retrospectively. Cases with scheduled multiple sheath insertions for a bidirectional approach were excluded. Twenty-three (79.3%) patients were male. Diabetes mellitus, hypertension, dyslipidemia, and smoking habit were present in 11 (37.9%), 27 (93.1%), 19 (65.5%), and 24 (82.8%) patients, respectively. Nine lesions (26.5%) were diagnosed as chronic total occlusion. All lesions were successfully treated using a total of 40 stents incorporating a 4.5 Fr radial access system. Ankle-brachial index (ABI) significantly improved from 0.68 ± 0.15 to 0.99 ± 0.17 (p < 0.0001) after the procedure. No patients had procedural or access site-related complications such as hematoma, major bleeding, blood transfusion, stroke, cholesterol embolism, aortic dissection, or arterial perforation. Radial artery occlusion was absent in all cases. ABI value was well maintained at 0.98 ± 0.13 at 1 year, and no target lesion revascularizations were reported. Slender transradial iliac artery stenting using a 4.5 Fr guiding sheath is safe, feasible, and less invasive, and shows no incidence of radial artery occlusion, in carefully selected patient populations.

Outcomes in Transcatheter Aortic Valve Replacement for Bicuspid Versus Tricuspid Aortic Valve Stenosis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is being increasingly performed in patients with bicuspid aortic valve stenosis (AS). OBJECTIVES: This study sought to compare the procedural and clinical outcomes in patients with bicuspid versus tricuspid AS from the Bicuspid AS TAVR multicenter registry. METHODS: Outcomes of 561 patients with bicuspid AS and 4,546 patients with tricuspid AS were compared after propensity score matching, assembling 546 pairs of patients with similar baseline characteristics. Procedural and clinical outcomes were recorded according to Valve Academic Research Consortium-2 criteria. RESULTS: Compared with patients with tricuspid AS, patients with bicuspid AS had more frequent conversion to surgery (2.0% vs. 0.2%; p = 0.006) and a significantly lower device success rate (85.3% vs. 91.4%; p = 0.002). Early-generation devices were implanted in 320 patients with bicuspid and 321 patients with tricuspid AS, whereas new-generation devices were implanted in 226 and 225 patients with bicuspid and tricuspid AS, respectively. Within the group receiving early-generation devices, bicuspid AS had more frequent aortic root injury (4.5% vs. 0.0%; p = 0.015) when receiving the balloon-expanding device, and moderate-to-severe paravalvular leak (19.4% vs. 10.5%; p = 0.02) when receiving the self-expanding device. Among patients with new-generation devices, however, procedural results were comparable across different prostheses. The cumulative all-cause mortality rates at 2 years were comparable between bicuspid and tricuspid AS (17.2% vs. 19.4%; p = 0.28). CONCLUSIONS: Compared with tricuspid AS, TAVR in bicuspid AS was associated with a similar prognosis, but lower device success rate. Procedural differences were observed in patients treated with the early-generation devices, whereas no differences were observed with the new-generation devices.

Percutaneous mitral valve repair with the MitraClip system in the elderly: One-year outcomes from the GRASP registry.

BACKGROUND: Although mitral regurgitation (MR) affects a relevant and increasing number of elderly, an optimal management of this high-risk population is challenging. METHODS AND RESULTS: The aim of this prospective, observational study was to compare one-year outcomes of MitraClip therapy in high surgical risk patients with moderate-to-severe or severe MR between patients aged <75 versus ≥75years. A total of 180 patients were included: 92 were <75years and 88 were ≥75years old. At one-year follow-up the primary efficacy endpoint (composite of death, surgery for mitral valve dysfunction and grade 3+ or 4+ MR) occurred in 41 patients (24.5%), with similar rates between those aged <75years (23.9%) and those ≥75years (25.2%), p=0.912. A total of 21 (12.2%) deaths were observed within 1year after the MitraClip procedure, without significant differences in cumulative mortality rates between elderly and younger patients (10.8% vs. 13.3%, respectively, p=0.574). Compared with baseline, the significant reduction in MR severity achieved after the procedure was sustained at one-year follow-up, in both elderly and younger patients and a significant improvement in NYHA functional class was observed in both groups. A total of 18 (10.0%) patients experienced a re-hospitalization for acute heart failure within one-year after the MitraClip procedure, with no significant differences between elderly and younger. At one-year follow-up both elderly and younger patients showed significant reductions in left ventricular volumes, with changes of similar extent between the two subgroups. CONCLUSIONS: MitraClip therapy can be considered a viable option also among subsets with more advanced age.

Impact of chronic kidney disease on outcomes after percutaneous mitral valve repair with the MitraClip system: insights from the GRASP registry.

AIMS: Our aim was to evaluate the impact of baseline chronic kidney disease (CKD) on clinical outcomes after percutaneous edge-to-edge mitral valve repair (PMVR). METHODS AND RESULTS: Two hundred and fourteen consecutive patients dichotomised by the presence of baseline CKD (n=113) or no-CKD (n=101) had their clinical outcomes compared up to 12-month follow-up. The primary safety endpoint was the incidence of major adverse events and the primary efficacy endpoint was freedom from death, surgery for MV dysfunction, or grade ≥3+ MR. The primary safety endpoint was demonstrated in 12.4% vs. 2.0% in CKD and no-CKD patients, respectively (p=0.003). The primary efficacy endpoint at 12 months was significantly lower in CKD patients (65.8% vs. 84.2%, respectively, log-rank p=0.005). While MR reduction and NYHA functional class improvement were mostly sustained and equivalent up to 12 months in no-CKD patients, they were impaired in CKD patients. Baseline CKD was an independent predictor of the primary efficacy endpoint (adjusted HR 2.48, 95% CI: 1.29 to 4.79, p=0.006) and calcified leaflet predicted grade ≥3+ MR at 12 months (adjusted HR 6.56, 95% CI: 2.71 to 15.88, p<0.001). CONCLUSIONS: CKD patients had worse clinical outcomes compared with no-CKD patients post PMVR. CKD was an independent predictor of the primary efficacy endpoint, whereas calcified leaflet was an independent predictor of grade ≥3+ MR at 12 months.

Comparison of aortic root anatomy and calcification distribution between Asian and Caucasian patients who underwent transcatheter aortic valve implantation.

The current transcatheter aortic valve implantation (TAVI) devices have been designed to fit Caucasian and Latin American aortic root anatomies. We evaluated the racial differences in aortic root anatomy and calcium distribution in patients with aortic stenosis who underwent TAVI. We conducted a multicenter study of 4 centers in Asia and Europe, which includes consecutive patients who underwent TAVI with preprocedural multidetector computed tomography. Quantitative assessment of aortic root dimensions, calcium volume for leaflet, and left ventricular outflow tract were retrospectively performed in a centralized core laboratory. A total of 308 patients (Asian group, n = 202; Caucasian group, n = 106) were analyzed. Compared to Caucasian group, Asian group had smaller annulus area (406.3 ± 69.8 vs 430.0 ± 76.8 mm(2); p = 0.007) and left coronary cusp diameter (30.2 ± 3.2 vs 31.1 ± 3.4 mm; p = 0.02) and lower height of left coronary artery ostia (12.0 ± 2.5 vs 13.4 ± 3.4 mm; p <0.001). Of baseline anatomic characteristics, body height showed the highest correlation with annulus area (Pearson correlation r = 0.64; p <0.001). Co-existence of lower height of left coronary artery ostia (<12 mm) and small diameter of left coronary cusp (<30 mm) were more frequent in Asian group compared with Caucasian group (35.6% vs 20.8%; p = 0.02). In contrast, there were no differences in calcium volumes of leaflet (367.2 ± 322.5 vs 359.1 ± 325.7 mm(3); p = 0.84) and left ventricular outflow tract (8.9 ± 23.4 vs 10.1 ± 23.8 mm(3); p = 0.66) between 2 groups. In conclusion, judicious consideration will be required to perform TAVI for short patients with lower height of left coronary artery ostia and small sinus of Valsalva.

Transcatheter Aortic Valve Implantation Under Angiographic Guidance With and Without Adjunctive Transesophageal Echocardiography.

Although transcatheter aortic valve implantation (TAVI) is still currently guided by transesophageal echocardiography (TEE) in a considerable number of hospitals, exclusive angiographic (Angio) guidance seems a reasonable approach in this setting. To date, however, no studies have directly compared the outcomes of TAVI according to the imaging modality used for procedural guidance. We, therefore, used data from a large multicenter data repository to compare the outcomes of TAVI guided exclusively by Angio and ATEE. All consecutive patients with severe aortic stenosis who underwent TAVI with the CoreValve Revalving System (CRS) in 9 Italian centers from September 2007 to March 2014, dichotomized according to the imaging support used to guide the procedure (ATEE and Angio), were included. Thirty-day and 12-month clinical outcomes were evaluated. Propensity matching analysis was performed to adjust for baseline differences. A total of 625 patients were included (256 and 369 patients were included in the ATEE and Angio groups, respectively). Patients from the ATEE more frequently underwent TAVI under general anesthesia compared with Angio group (37.9% vs 22.8%, respectively, p <0.001). Importantly, ∼80% of the patients experienced mild or even less aortic regurgitation as assessed by angiography after the procedure, without between-group differences. Postdilation and valve-in-valve rates were equivalent (24.7% vs 25%, p = 0.934 and 5.5% vs 3.4%, respectively, p = 0.217). No differences were revealed in the rates of death, cardiovascular death, and stroke or transient ischemic attack at 12-month follow-up. These results were sustained after propensity matching analysis. In conclusion, as long as a comprehensive procedural planning is performed, TAVI with CRS may be performed exclusively under angiographic guidance without the need for associated TEE.

Current status and clinical development of transcatheter approaches for severe mitral regurgitation.

Transcatheter mitral valve intervention has emerged as an effective treatment option for symptomatic severe mitral regurgitation in patients considered to be inoperable or at high operative risk for surgical mitral valve surgery. Most transcatheter approaches are modifications of existing surgical approaches. Transcatheter edge-to-edge mitral valve repair with the MitraClip system has the largest clinical experience to date, as it offers a sustained clinical benefit in selected patients. This review aims to provide an up-to-date overview of transcatheter mitral valve interventions, including leaflet repair, annuloplasty, and mitral valve implantation.

Gender-related clinical and echocardiographic outcomes at 30-day and 12-month follow up after MitraClip implantation in the GRASP registry.

OBJECTIVES: To assess the influence of patients' gender on the outcomes of percutaneous edge-to-edge mitral valve repair (PMVR) using the MitraClip system. BACKGROUND: Although gender-related differences have been extensively documented in patients who undergo surgery for moderate-to-severe (3+) and severe (4+) mitral regurgitation (MR), studies assessing whether these differences exist after PMVR are lacking. METHODS: Clinical and echocardiographic data through 12-month follow up from 171 consecutive patients whom underwent MitraClip implantation and were dichotomized by the gender (106 males and 65 females) were obtained. The primary safety endpoint was the incidence of major adverse events at 30 days and the primary efficacy endpoint was freedom from death, surgery for mitral valve dysfunction, or grade≥3+ MR at 12-month follow up. RESULTS: The primary safety endpoint was observed in four males (3.8%) and four females (6.2%) (P=0.358). Remarkable reduction in MR postprocedure was revealed in both groups, and these results were mostly sustained. Furthermore, left ventricle reverse remodeling and New York Heart Association (NYHA) functional class improvement were revealed in both groups, but females tended to demonstrate worse results over time (P=0.083). The primary efficacy endpoint obtained by Kaplan-Meier estimates was observed in 76.3 and 70.2%, respectively (log rank P=0.231). CONCLUSIONS: MitraClip implantation in patients with 3+ and 4+ MR is safe and efficacious until mid-term follow up, regardless of patients' gender. Despite improvement in NYHA functional class in both groups, female gender demonstrated a trend toward poorer results. Further validation of our findings is warranted.

Extended use of percutaneous edge-to-edge mitral valve repair beyond EVEREST (Endovascular Valve Edge-to-Edge Repair) criteria: 30-day and 12-month clinical and echocardiographic outcomes from the GRASP (Getting Reduction of Mitral Insufficiency by Percutaneous Clip Implantation) registry.

OBJECTIVES: This study sought to compare, in high-risk patients with 3+ to 4+ mitral regurgitation (MR) dichotomized by baseline echocardiographic features, acute, 30-day, and 12-month outcomes following percutaneous mitral valve repair using the MitraClip. BACKGROUND: The feasibility and mid-term outcomes after MitraClip implantation in patients with echocardiographic features different from the EVEREST (Endovascular Valve Edge-to-Edge Repair) I and II trials have been scarcely studied. METHODS: Clinical and echocardiographic outcomes through 12-month follow-up of consecutive patients who underwent MitraClip implantation were obtained from an ongoing prospective registry. Two different groups, divided according to baseline echocardiographic criteria (investigational group [EVERESTOFF] and control group [EVERESTON]), were compared. RESULTS: Seventy-eight patients were included in EVERESTOFF and 93 patients in EVERESTON groups. Important and comparable acute reductions in MR and no clip-related complications were revealed. The primary safety endpoint at 30 days was comparable between groups (2.6% vs. 6.5%, respectively, p = 0.204); in addition, MR reduction was mostly sustained, whereas equivalent improvement in New York Heart Association functional class were demonstrated. Kaplan-Meier freedom from death, surgery for mitral valve dysfunction, or grade ≥3+ MR at 12 months was demonstrated in 71.4% and 76.2%, respectively, in the EVERESTOFF and EVERESTON groups (log rank p = 0.378). Significant improvements in ejection fraction and reduction in left ventricle volumes were demonstrated in both groups over time, but the baseline between-group differences were sustained. CONCLUSIONS: MitraClip implantation in patients with expanded baseline echocardiographic features, compared with the control group, was associated with similar rates of safety and efficacy through 12-month follow-up. Further validation of our findings is warranted.

Impact of balloon post-dilation on clinical outcomes after transcatheter aortic valve replacement with the self-expanding CoreValve prosthesis.

OBJECTIVES: The aim of this study was to assess the incidence and clinical impact of balloon post-dilation (BPD) after transcatheter aortic valve replacement (TAVR) with the CoreValve prosthesis (Medtronic Inc., Minneapolis, Minnesota). BACKGROUND: BPD is a widely adopted strategy to reduce the degree of paraprosthetic regurgitation in case of transcatheter heart valve underexpansion. However, controversies still remain regarding its real effectiveness and safety. METHODS: The ClinicalService (a nation-based data repository and medical care project) dataset was analyzed. All patients were dichotomized according to the need for BPD during the index procedure. RESULTS: Among 1,376 patients, BPD of the transcatheter heart valve was performed in 272 (19.8%). In 37% of cases, it was unsuccessful at reducing the paravalvular regurgitation to mild or less. No case of valve embolization, new intravalvular regurgitation, coronary occlusion, and aortic root injury occurred during BPD. There were no statistically significant differences between the 2 groups in the incidence of in-hospital all-cause and cardiovascular mortality, neurological events, myocardial infarction, bleeding, conversion to open-chest surgery, and the need for a permanent pacemaker. The need for BPD did not emerge as an independent risk factor for all-cause (adjusted hazard ratio [HR]: 1.33, 95% confidence interval [CI]: 0.81 to 2.19, p = 0.264) and cardiovascular (adjusted HR: 1.48, 95% CI: 0.74 to 2.97, p = 0.265) mortality at 1 year after the procedure. In addition, BPD did not predispose to higher odds of neurological events during 12 months after TAVR (HR: 0.92, 95% CI: 0.45 to 1.88, p = 0.815). CONCLUSIONS: This large study showed that BPD after TAVR was safe and not associated with increased rates of cerebrovascular events, mortality, myocardial infarction, and aortic root injury.

Association of tricuspid regurgitation with clinical and echocardiographic outcomes after percutaneous mitral valve repair with the MitraClip System: 30-day and 12-month follow-up from the GRASP Registry.

AIM: The aim of this study was to evaluate the association of baseline tricuspid regurgitation (TR) on the outcomes after percutaneous mitral valve repair (PMVR) with the MitraClip system. METHODS AND RESULTS: Data from 146 consecutive patients with functional mitral regurgitation (MR) were obtained. Two different groups, dichotomized according to the degree of pre-procedural TR (moderate/severe, n = 47 and none/mild, n = 99), had their clinical and echocardiographic outcomes through 12-month compared. At 30-day, the primary safety endpoint was significantly higher in moderate/severe TR compared with none/mild TR (10.6 vs. 2.0%, P = 0.035). Marked reduction in MR grades observed post-procedure were maintained through 12 months. Although NYHA functional class significantly improved in both groups compared with baseline, it was impaired in moderate/severe TR compared with the none/mild TR group (NYHA > II at 30 day: 33.3 vs. 9.2%, P < 0.001; at 1 year: 38.5 vs. 12.3%, respectively, P = 0.006). Left ventricle reverse remodelling and ejection fraction improvement were revealed in both groups. The primary efficacy endpoint at 12-month determined by freedom from death, surgery for mitral valve dysfunction, or grade ≥ 3+ MR was comparable between groups, but combined death and re-hospitalization for heart failure rates were higher in the moderate/severe TR group. Multivariable Cox regression analysis demonstrated that baseline moderate/severe TR and chronic kidney disease were independent predictors of this combined endpoint. CONCLUSIONS: Although PMVR with MitraClip led to improvement in MR, TR, and NYHA functional class in patients with baseline moderate/severe TR, the primary safety endpoint at 30-day was impaired, while moderate/severe TR independently predicted death and re-hospitalization for heart failure at 12-month.

Distinct iPS Cells Show Different Cardiac Differentiation Efficiency.

Patient-specific induced pluripotent stem (iPS) cells can be generated by introducing transcription factors that are highly expressed in embryonic stem (ES) cells into somatic cells. This opens up new possibilities for cell transplantation-based regenerative medicine by overcoming the ethical issues and immunological problems associated with ES cells. Despite the development of various methods for the generation of iPS cells that have resulted in increased efficiency, safety, and general versatility, it remains unknown which types of iPS cells are suitable for clinical use. Therefore, the aims of the present study were to assess (1) the differentiation potential, time course, and efficiency of different types of iPS cell lines to differentiate into cardiomyocytes in vitro and (2) the properties of the iPS cell-derived cardiomyocytes. We found that high-quality iPS cells exhibited better cardiomyocyte differentiation in terms of the time course and efficiency of differentiation than low-quality iPS cells, which hardly ever differentiated into cardiomyocytes. Because of the different properties of the various iPS cell lines such as cardiac differentiation efficiency and potential safety hazards, newly established iPS cell lines must be characterized prior to their use in cardiac regenerative medicine.

Intracardiac echocardiography for percutaneous closure of atrial septal defects: initial experiences in Japan.

Transcatheter closure of secundum atrial septal defect (ASD) has been widely performed as a less invasive alternative to surgery with zero mortality so far in Japan. In the US and Europe, intracardiac echocardiography (ICE) has replaced transesophageal echocardiography (TEE) as a primary imaging tool during percutaneous ASD closure. However, the experience of ICE in ASD closure is limited in Japan. Consecutive 51 patients underwent percutaneous ASD closure with ICE guidance. Clinical results were compared to those of 41 patients who underwent ASD closure with TEE guidance. Pediatric patients and patients with multiple ASDs who were expected to need multiple devices were excluded. Success rate was similar in both groups (ICE 96.1 %, TEE 92.7 %). Catheterization laboratory time was significantly shortened with ICE than with TEE (131 vs. 155 min, p = 0.0003). There were no complications related to the use of ICE. ICE-guided ASD closure is feasible in most adult patients. ICE is superior to TEE in shortening catheterization laboratory time and eliminating general anesthesia, and can potentially replace TEE as the primary image guide during percutaneous ASD closure.

Disease characterization using LQTS-specific induced pluripotent stem cells.

AIMS: Long QT syndrome (LQTS) is an inheritable and life-threatening disease; however, it is often difficult to determine disease characteristics in sporadic cases with novel mutations, and more precise analysis is necessary for the successful development of evidence-based clinical therapies. This study thus sought to better characterize ion channel cardiac disorders using induced pluripotent stem cells (iPSCs). METHODS AND RESULTS: We reprogrammed somatic cells from a patient with sporadic LQTS and from controls, and differentiated them into cardiomyocytes through embryoid body (EB) formation. Electrophysiological analysis of the LQTS-iPSC-derived EBs using a multi-electrode array (MEA) system revealed a markedly prolonged field potential duration (FPD). The IKr blocker E4031 significantly prolonged FPD in control- and LQTS-iPSC-derived EBs and induced frequent severe arrhythmia only in LQTS-iPSC-derived EBs. The IKs blocker chromanol 293B did not prolong FPD in the LQTS-iPSC-derived EBs, but significantly prolonged FPD in the control EBs, suggesting the involvement of IKs disturbance in the patient. Patch-clamp analysis and immunostaining confirmed a dominant-negative role for 1893delC in IKs channels due to a trafficking deficiency in iPSC-derived cardiomyocytes and human embryonic kidney (HEK) cells. CONCLUSIONS: This study demonstrated that iPSCs could be useful to characterize LQTS disease as well as drug responses in the LQTS patient with a novel mutation. Such analyses may in turn lead to future progress in personalized medicine.

Wnt2 accelerates cardiac myocyte differentiation from ES-cell derived mesodermal cells via non-canonical pathway.

The efficient induction of cardiomyocyte differentiation from embryonic stem (ES) cells is crucial for cardiac regenerative medicine. Although Wnts play important roles in cardiac development, complex questions remain as to when, how and what types of Wnts are involved in cardiogenesis. We found that Wnt2 was strongly up-regulated during cardiomyocyte differentiation from ES cells. Therefore, we investigated when and how Wnt2 acts in cardiogenesis during ES cell differentiation. Wnt2 was strongly expressed in the early developing murine heart. We applied this embryonic Wnt2 expression pattern to ES cell differentiation, to elucidate Wnt2 function in cardiomyocyte differentiation. Wnt2 knockdown revealed that intrinsic Wnt2 was essential for efficient cardiomyocyte differentiation from ES cells. Moreover, exogenous Wnt2 increased cardiomyocyte differentiation from ES cells. Interestingly, the effects on cardiogenesis of intrinsic Wnt2 knockdown and exogenous Wnt2 addition were temporally restricted. During cardiomyocyte differentiation from ES cells, Wnt2 didn't activate canonical Wnt pathway but utilizes JNK/AP-1 pathway which is required for cardiomyocyte differentiation from ES cells. Therefore we conclude that Wnt2 plays strong positive stage-specific role in cardiogenesis through non-canonical Wnt pathway in murine ES cells.

Neural crest-derived stem cells migrate and differentiate into cardiomyocytes after myocardial infarction.

OBJECTIVE: We recently demonstrated that primitive neural crest-derived (NC) cells migrate from the cardiac neural crest during embryonic development and remain in the heart as dormant stem cells, with the capacity to differentiate into various cell types, including cardiomyocytes. Here, we examined the migration and differentiation potential of these cells on myocardial infarction (MI). METHODS AND RESULTS: We obtained double-transgenic mice by crossing protein-0 promoter-Cre mice with Floxed-enhanced green fluorescent protein mice, in which the NC cells express enhanced green fluorescent protein. In the neonatal heart, NC stem cells (NCSCs) were localized predominantly in the outflow tract, but they were also distributed in a gradient from base to apex throughout the ventricular myocardium. Time-lapse video analysis revealed that the NCSCs were migratory. Some NCSCs persisted in the adult heart. On MI, NCSCs accumulated at the ischemic border zone area (BZA), which expresses monocyte chemoattractant protein-1 (MCP-1). Ex vivo cell migration assays demonstrated that MCP-1 induced NCSC migration and that this chemotactic effect was significantly depressed by an anti-MCP-1 antibody. Small NC cardiomyocytes first appeared in the BZA 2 weeks post-MI and gradually increased in number thereafter. CONCLUSIONS: These results suggested that NCSCs migrate into the BZA via MCP-1/CCR2 signaling and contribute to the provision of cardiomyocytes for cardiac regeneration after MI.