Application of the RIETE score to identify low-risk patients with pulmonary embolism: From the COMMAND VTE Registry.

BACKGROUND: The RIETE score could be specifically useful for identification of low-risk pulmonary embolism (PE) patients for home treatment. However, the external validation of the RIETE score has been limited. METHODS: The COMMAND VTE Registry is a multicenter registry enrolling consecutive patients with acute symptomatic venous thromboembolism (VTE). The current study population consisted of 1479 patients with acute PE, who were divided into 2 groups; RIETE scores of 0 (N = 260) and ≥ 1 (N = 1219). RESULTS: The cumulative 10-day and 30-day incidences of a composite endpoint of all-cause death, recurrent PE, or major bleeding were lower in patients with the RIETE score of 0 than in those with the RIETE score of ≥1 (10-day: 0.4 % vs. 6.7 %, P < 0.001, and 30-day: 0.4 % vs. 10.0 %, P < 0.001). The area under the receiver-operating characteristic curve (AUC) in the RIETE score for the 10-day composite endpoint showed numerically better predictive ability than that in the sPESI score (0.77 vs. 0.73, P = 0.07), and the AUC in the RIETE score for the 30-day composite endpoint showed significantly better predictive ability than that in the sPESI score (0.77 vs. 0.71, P = 0.003). CONCLUSIONS: The RIETE score was well validated in the current large real-world registry. The RIETE score of 0 could identify patients with reasonably low risks of the 10-day and 30-day composite endpoint of all-cause death, recurrent PE, or major bleeding.

Am80, a retinoic acid receptor agonist, activates the cardiomyocyte cell cycle and enhances engraftment in the heart.

Human induced pluripotent stem cell-derived (hiPSC) cardiomyocytes are a promising source for regenerative therapy. To realize this therapy, however, their engraftment potential after their injection into the host heart should be improved. Here, we established an efficient method to analyze the cell cycle activity of hiPSC cardiomyocytes using a fluorescence ubiquitination-based cell cycle indicator (FUCCI) system. In vitro high-throughput screening using FUCCI identified a retinoic acid receptor (RAR) agonist, Am80, as an effective cell cycle activator in hiPSC cardiomyocytes. The transplantation of hiPSC cardiomyocytes treated with Am80 before the injection significantly enhanced the engraftment in damaged mouse heart for 6 months. Finally, we revealed that the activation of endogenous Wnt pathways through both RARA and RARB underlies the Am80-mediated cell cycle activation. Collectively, this study highlights an efficient method to activate cell cycle in hiPSC cardiomyocytes by Am80 as a means to increase the graft size after cell transplantation into a damaged heart.

Immunosuppressants Tacrolimus and Sirolimus revert the cardiac antifibrotic properties of p38-MAPK inhibition in 3D-multicellular human iPSC-heart organoids.

Cardiac reactive fibrosis is a fibroblast-derived maladaptive process to tissue injury that exacerbates an uncontrolled deposition of large amounts of extracellular matrix (ECM) around cardiomyocytes and vascular cells, being recognized as a pathological entity of morbidity and mortality. Cardiac fibrosis is partially controlled through the sustained activation of TGF-ß1 through IL-11 in fibroblasts. Yet, preclinical studies on fibrosis treatment require human physiological approaches due to the multicellular crosstalk between cells and tissues in the heart. Here, we leveraged an iPSC-derived multi-lineage human heart organoid (hHO) platform composed of different cardiac cell types to set the basis of a preclinical model for evaluating drug cardiotoxicity and assessing cardiac fibrosis phenotypes. We found that the inhibition of the p38-MAPK pathway significantly reduces COL1A1 depositions. Yet, concomitant treatment with organ-rejection immunosuppressant drugs Tacrolimus or Sirolimus reverts this effect, opening new questions on the clinical considerations of combined therapies in reducing fibrosis after organ transplantation.

Purification of human iPSC-derived cells at large scale using microRNA switch and magnetic-activated cell sorting.

For regenerative cell therapies using pluripotent stem cell (PSC)-derived cells, large quantities of purified cells are required. Magnetic-activated cell sorting (MACS) is a powerful approach to collect target antigen-positive cells; however, it remains a challenge to purify various cell types efficiently at large scale without using antibodies specific to the desired cell type. Here we develop a technology that combines microRNA (miRNA)-responsive mRNA switch (miR-switch) with MACS (miR-switch-MACS) to purify large amounts of PSC-derived cells rapidly and effectively. We designed miR-switches that detect specific miRNAs expressed in target cells and controlled the translation of a CD4-coding transgene as a selection marker for MACS. For the large-scale purification of induced PSC-derived cardiomyocytes (iPSC-CMs), we transferred miR-208a-CD4 switch-MACS and obtained purified iPSC-CMs efficiently. Moreover, miR-375-CD4 switch-MACS highly purified pancreatic insulin-producing cells and their progenitors expressing Chromogranin A. Overall, the miR-switch-MACS method can efficiently purify target PSC-derived cells for cell replacement therapy.

Periprocedural management and clinical outcomes of invasive procedures after venous thromboembolism: from the COMMAND VTE registry.

Anticoagulation therapy is prescribed for the prevention of recurrence in patients with venous thromboembolism, which could be temporarily interrupted during invasive procedures. The COMMAND VTE Registry is a multicenter registry enrolling 3027 consecutive patients with acute symptomatic VTE in Japan between January 2010 and August 2014. We identified patients who underwent invasive procedures during the entire follow-up period and evaluated periprocedural managements and clinical outcomes at 30 days after invasive procedures. During a median follow-up period of 1213 (IQR: 847-1764) days, 518 patients underwent invasive procedures with the cumulative incidences of 5.8% at 3 months, 11.1% at 1 year, and 24.0% at 5 years. Among 382 patients in high bleeding-risk category of invasive procedures, anticoagulation therapy had been discontinued already in 62 patients (16%) and interrupted temporarily in 288 patients (75%) during the invasive procedures with bridging anticoagulation therapy with heparin in 214 patients (56%). Among 80 patients in low bleeding-risk category, anticoagulation therapy had been already discontinued in 15 patients (19%) and interrupted temporarily in 31 patients (39%) during invasive procedure with bridging anticoagulation therapy with heparin in 17 patients (21%). At 30 days after the invasive procedures, 14 patients (2.7%) experienced recurrent VTE, while 28 patients (5.4%) had major bleeding. This study elucidated the real-world features of peri-procedural management and prognosis in patients with VTE who underwent invasive procedures during follow-up in the large multicenter VTE registry. The 30-day incidence rates of recurrent VTE and major bleeding events were 2.7% and 5.4%.

Mechanism of improvement in atrial functional mitral regurgitation after catheter ablation for atrial fibrillation: Three-dimensional analysis using multislice computed tomography.

BACKGROUND: Several factors associated with atrial functional mitral regurgitation development have been reported; however, geometric changes in the mitral apparatus after catheter ablation for atrial fibrillation have not been sufficiently investigated. This study aimed to clarify what determines improvements in atrial functional mitral regurgitation after sinus rhythm restoration in patients who underwent catheter ablation for atrial fibrillation by using multislice computed tomography. METHODS: We analysed volumetric multislice computed tomography images of 44 atrial fibrillation patients with significant atrial functional mitral regurgitation (moderate or worse) before and after catheter ablation. We measured the three-dimensional geometry of the mitral apparatus including the mitral annular area and interpapillary muscle distance. We calculated the differences before and after catheter ablation (Δmitral annular area, Δinterpapillary muscle distance) and assessed mitral regurgitation severity based on the mitral regurgitant jet area and its changes before and after catheter ablation (Δjet area) using transthoracic echocardiography. RESULTS: After catheter ablation, the jet area was significantly decreased. The left ventricular ejection fraction was significantly increased and the left ventricular volume had a decreasing trend. The Δjet area was significantly correlated with the Δinterpapillary muscle distance (r = .43; p = .004). The Δinterpapillary muscle distance was the strongest determinant of improvements in atrial functional mitral regurgitation severity (p = .026). CONCLUSIONS: Decreased interpapillary muscle distance was strongly associated with improvements in atrial functional mitral regurgitation. Amelioration of left ventricular dysfunction by sinus rhythm restoration might be related to improvements in atrial functional mitral regurgitation after catheter ablation.

Infrequent use of nighttime dialysis for emergency admission due to worsening heart failure in patients on maintenance hemodialysis.

In the emergency admission due to worsening heart failure (HF) in patients on maintenance hemodialysis, emergent dialysis may be indicated, which increases personnel expenses. To clarify the characteristics and in-hospital management of the patients, we conducted a multicenter retrospective study including 142 patients on maintenance hemodialysis emergently admitted for worsening HF (71.6 ± 9.2 years, 69.0% male, 44.4% HF with preserved [≥50%] ejection fraction). The interval between last hemodialysis and admission was long (median 55 h), suggesting that fluid accumulation triggered HF events. Although most patients (73.9%) were admitted in the nighttime (5 p.m. to 9 a.m.), only 17.9% of them needed nighttime dialysis and were managed medically until the first in-hospital dialysis, with the use of noninvasive positive pressure ventilation in 45.1% and oxygen supplementation in 95.8%. While patients on hemodialysis with worsening HF were frequently admitted in the nighttime, nighttime dialysis was indicated in a limited population.

Sole Obstruction of the Inferior Mesenteric Artery With Acute Aortic Dissection Causing Critical Mesenteric Ischemia.

Inferior mesenteric artery obstruction rarely causes critical mesenteric ischemia, because of the good collateral blood supply. We report a rare case of critical mesenteric ischemia due to sole inferior mesenteric artery obstruction accompanied by acute aortic dissection. Early diagnosis and treatment of mesenteric ischemia are important. (Level of Difficulty: Advanced.).