Objective Stem cell therapy for angiogenesis and vascular regeneration has been investigated using adult or embryonic stem cells. In the present study, we investigated the potential of endothelial cells (ECs) derived from human induced pluripotent stem cells (hiPSCs) to promote the perfusion of ischemic tissue in a murine model of peripheral arterial disease. Methods and Results Endothelial differentiation was initiated by culturing hiPSCs for 14 days in differentiation media supplemented with BMP-4 and VEGF. The hiPSC-ECs exhibited endothelial characteristics by forming capillary-like structures in matrigel and incorporating acetylated-LDL. They stained positively for EC markers such as KDR, CD31, CD144 and eNOS. In vitro exposure of hiPSC-ECs to hypoxia resulted in increased expression of various angiogenic related cytokines and growth factors. hiPSC-ECs were stably transduced with a double fusion construct encoded by the ubiquitin promoter, firefly luciferase for bioluminescence imaging (BLI) and green fluorescence protein (GFP) for fluorescent detection (pUb-Fluc-GFP). The hiPSC-ECs (5×105) were delivered by intramuscular injection into the ischemic hindlimb of SCID mice at day 0 and again on day 7 after femoral artery ligation (n=8). BLI showed that hiPSC-ECs survived in the ischemic limb for at least 2 weeks. In addition, laser Doppler imaging showed that the ratio of blood perfusion was increased by hiPSC-EC treatment by comparison to the saline-treated group (0.58±0.12 vs 0.44±0.04; P=0.005). The total number of capillaries in the ischemic limb of mice receiving hiPSC-EC injections was greater than those in the saline-treated group (1284 ±155 vs. 797±206 capillaries/mm2) (P<0.002). Conclusion This study is a first step toward development of a regenerative strategy for peripheral arterial disease based on the use of ECs derived from hiPSCs.

Milk fat globule epidermal growth factor 8 (Mfge8) is a soluble glycoprotein known to regulate inflammation and immunity by mediating apoptotic cell clearance. Since fibrosis can occur as a result of exaggerated apoptosis and inflammation, we set out to investigate the hypothesis that Mfge8 might negatively regulate tissue fibrosis. We report here that Mfge8 does decrease the severity of tissue fibrosis in a mouse model of pulmonary fibrosis; however, it does so not through effects on inflammation and apoptotic cell clearance, but by binding and targeting collagen for cellular uptake through its discoidin domains. Initial analysis revealed that Mfge8 -/-mice exhibited enhanced pulmonary fibrosis after bleomycin-induced lung injury. However, they did not have increased inflammation or impaired apoptotic cell clearance after lung injury compared with Mfge8 +/+ mice; rather, they had a defect in collagen turnover. Further experiments indicated that Mfge8 directly bound collagen and that Mfge8 -/-macrophages exhibited defective collagen uptake that could be rescued by recombinant Mfge8 containing at least one discoidin domain. These data demonstrate a critical role for Mfge8 in decreasing the severity of murine tissue fibrosis by facilitating the removal of accumulated collagen.

Prevention of stroke and systemic thromboembolism remains the cornerstone for management of atrial fibrillation (AF) and flutter. Multiple risk assessment models for stroke and systemic thromboembolism are currently available. The score, with its known limitations, remains as the recommended risk stratification tool in most major guidelines. Once at-risk patients are identified, vitamin K antagonists (VKAs) and, more recently, direct oral anticoagulants (DOACs) are the primary medical therapy for stroke prevention. In those with contraindication for long-term anticoagulation, left atrial appendage occluding devices are developing as a possible alternative therapy. Some controversy exists regarding anticoagulation management for cardioversion of acute AF (<48 hours); however, systemic anticoagulation precardioversion and postcardioversion is recommended for those with longer duration of AF. Anticoagulation management peri-AF ablation is also evolving. Uninterrupted VKA and DOAC therapy has been shown to reduce perioperative thromboembolic risk with no significant escalation in major bleeding. Currently, under investigation is a minimally interrupted approach to anticoagulation with DOACs periablation. Questions remain, especially regarding the delivery of anticoagulation care and integration of wearable rhythm monitors in AF management.

A slowly escalating bridging regimen of UFH, followed by 3 months of oral anticoagulation, is associated with low thromboembolic and bleeding risks after infarct-related VT ablation. In the absence of extensive ablation, antiplatelet therapy alone is reasonable.

Background Little is known about the opinions of primary care clinicians regarding the newly released 2013 ACC/AHA (American College of Cardiology/American Heart Association) Guidelines for the Prevention of Primary and Secondary Atherosclerotic Disease. This survey was created to assess the awareness, attitudes and practices of primary care clinicians on adoption of the new guidelines and to explore obstacles to implementation and suggestions for improved shared decision making. Methods 600 practicing clinicians within the San Francisco Bay Area Collaborative Research Network were invited to participate in this cross-sectional, internet-based pilot survey of primary care clinicians. These survey data were collected in March 2014, approximately four months after the release of the new guidelines and one month after the release of the ACC/AHA risk estimator application. Results 183 clinicians responded to the survey. Of those respondents, 176 (96%) were aware of the guidelines. The majority (64%) reported implementing the new guidelines with at least some of their patients, while a minority (25%) reported adopting the guidelines for many of their patients. Disagreeing with the guidelines was the main hindrance to adoption. Conclusions While many primary care clinicians are aware of the new guidelines, a substantial proportion has yet to implement them into their clinical practice and obstacles remain for full adoption. Further understanding of clinicians’ views, opinions and needs is necessary to optimize the approach to lipid management and ensure integration into current practice.