The usefulness of mesenchymal stem cells beyond the musculoskeletal system in horses

The differentiation ability of mesenchymal stem cells (MSCs) initially raised interest for treating musculoskeletal injuries in horses, but MSC paracrine activity has widened their scope for inflammatory and immune-mediated pathologies in both equine and human medicine. Further-more, the similar etiopathogenesis of some diseases in both species has advanced the concept of “One Medicine, One Health”. This article reviews the current knowledge on the use of MSCs for equine pathologies beyond the locomotor system, highlighting the value of the horse as translational model. Ophthalmologic and reproductive disorders are among the most studied for MSC application. Equine asthma, equine metabolic syndrome, and endotoxemia have been less explored but offer an interesting scenario for human translation. The use of MSCs in wounds also provides a potential model for humans because of the healing particularities in both species. High-burden eq-uine-specific pathologies such as laminitis have been suggested to benefit from MSC-therapy, and MSC application in challenging disorders such as neurologic conditions has been proposed. The available data are preliminary, however, and require further development to translate results into the clinic. Nevertheless, current evidence indicates a significant potential of equine MSCs to enlarge their range of application, with particular interest in pathologies analogous to human conditions

Humoral immune response against allogeneic equine mesenchymal stem cells (MSCs) mediated by the major histocompatibility complex (MHC): an issue to take into account for the safety and efficacy of treatment with MSCs

Allogeneic mesenchymal stem cells (MSCs) present several advantages, but recipient immune response needs to be further elucidated. Proinflammatory priming of MSCs activated their in vivo regulatory capacity, but repeated administrations led to slight inflammatory reaction in an osteoarthritis equine model. This may be associated with higher major histocompatibility complex (MHC) expression, which would increase MSC immunogenicity potentially inducing humoral mediated immune memory. This study aimed at assessing allo-antibody production against donor’s equine MHC (equine leukocyte antigen, ELA) in animals that received intra-articular repeated administration of allogeneic MSC-primed. For this purpose, we used stored samples from a previous study. Donor and recipients ELA-haplotypes were stablished by microsatellite typing and complementmediated microcytoxicity assays were carried out by exposing target cells from the donor (unstimulated MSCs [MSC-nai¨ve], MSC-primed or lymphocytes [control]) to sera collected at different time-points from 10 recipients: ELA-mismatched MSCnai ¨ve recipients, ELA-mismatched MSC-primed recipients or ELA-partially matched MSC-primed recipients. All animals receiving allogeneic MSCs produced allo-antibodies after the first injection, regardless of the matching degree. However, antibody peak production after second administration was only observed in ELA-mismatched recipients, both of MSC-nai¨ve and MSCprimed. Horses injected with MSC-primed produced fewer antibodies but MSC-primed were more targeted in the microcytoxicity assay. Thus, activated immunomodulatory profile of MSC-primed could have led to slighter humoral response after ..

Impact of triple therapy in elderly patients with atrial fibrillation undergoing percutaneous coronary intervention

Background and Purpose: Selecting an ideal antithrombotic therapy for elderly patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) can be challenging since they have a higher thromboembolic and bleeding risk than younger patients. The current study aimed to assess the efficacy and safety of triple therapy (TT: oral anticoagulation plus dual antiplate- let therapy: aspirin plus clopidogrel) in patients > 75 years of age with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). Methods: A prospective multicenter study was conducted from 2003 to 2012 at 6 Spanish teaching hospitals. A cohort study of consecutive patients with AF undergoing PCI and treated with TT or dual antiplatelet therapy (DAPT) was analyzed. All outcomes were evaluated at 1- year of follow-up. Results: Five hundred and eighty-five patients, 289 (49%) of whom were > 75 years of age (79.6 ± 3.4 years; 33% women) were identified. TT was prescribed in 55.9% of patients at discharge who had a higher thromboembolic risk (CHA 2 DS 2 VASc score: 4.23 ± 1.51 vs 3.76 ± 1.40, p = 0.007 and a higher bleeding risk (HAS-BLED > 3: 88.6% vs 79.2%, p = 0.02) than those on DAPT. Therefore, patients on TT had a lower rate of thromboembolism than those on DAPT (0.6% vs 6.9%, p = 0.004; HR 0.08, 95% CI: 0.01 - 0.70, p = 0.004). Major bleeding events occurred more frequently in patients on TT than in those on DAPT (11.7% vs 2.4%, p = 0.002; HR 5.2, 95% CI: 1.53 - 17.57, p = 0.008). The overall mortality rate was similar in both treatment groups (11.9% vs 13.9%, p = 0.38); however, after adjustment for confounding variables, TT was associated with a reduced mortality rate (HR 0.33, 95% CI: 0.12 - 0.86, p = 0.02). Conclusions In elderly patients with AF undergoing PCI, the use of TT compared to DAPT was associ- ated with reduced thromboembolism and mortality rates, although a higher rate of major bleeding

Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events: Patient level meta-analysis

Objectives: To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents.Design: Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported.Data sources and study selection: Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients.Primary outcomes: The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death.Results: The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P<0.001), and target vessel revascularisation (0.29, 0.20 to 0.41; P<0.001) at a median follow-up of 720 days. There was no significant difference in all cause death between groups (0.83, 0.65 to 1.06; P=0.14). Findings remained unchanged at multivariable regression after adjustment for the acuity of clinical syndrome (for instance, acute coronary syndrome v stable coro

Preserved endothelium-dependent vasodilation in coronary segments previously treated with balloon angioplasty and intracoronary irradiation

BACKGROUND: Abnormal endothelium-dependent coronary vasomotion has been reported after balloon angioplasty (BA), as well as after intracoronary radiation. However, the long-term effect on coronary vasomotion is not known. The aim of this study was to evaluate the long-term vasomotion of coronary segments treated with BA and brachytherapy. METHODS AND RESULTS: Patients with single de novo lesions treated either with BA followed by intracoronary beta-irradiation (according to the Beta Energy Restenosis Trial-1.5) or with BA alone were eligible. Of these groups, those patients in stable condition who returned for 6-month angiographic follow-up formed the study population (n=19, irradiated group and n=11, control group). Endothelium-dependent coronary vasomotion was assessed by selective infusion of serial doses of acetylcholine (ACh) proximally to the treated area. Mean luminal diameter was calculated by quantitative coronary angiography both in the treated area and in distal segments. Endothelial dysfunction was defined as a vasoconstriction after the maximal dose of ACh (10(-6) mol/L). Seventeen irradiated segments (89.5%) demonstrated normal endothelial function. In contrast, 10 distal nonirradiated segments (53%) and 5 control segments (45%) demonstrated endothelium-dependent vasoconstriction (-19+/-17% and -9.0+/-5%, respectively). Mean percentage of change in mean luminal diameter after ACh was significantly higher in irradiated segments (P=0.01). CONCLUSIONS: Endothelium-dependent vasomotion of coronary segments treated with BA followed by beta-radiation is restored in the majority of stabl

Pre-hospital administration of ticagrelor in diabetic patients with ST-elevation myocardial infarction undergoing primary angioplasty: A sub-analysis of the ATLANTIC trial

Objective: We investigated, in the contemporary era of ST-elevation myocardial infarction (STEMI) treatment, the influence of diabetes mellitus (DM) on cardiovascular outcomes, and whether pre-hospital administration of ticagrelor may affect these outcomes in a subgroup of STEMI patients with DM. Background: DM patients have high platelet reactivity and a prothrombotic condition which highlight the importance of an effective antithrombotic regimen in this high-risk population. Methods: In toal 1,630 STEMI patients enrolled in the ATLANTIC trial who underwent primary percutaneous coronary intervention (PCI) were included. Multivariate analysis was used to explore the association of DM with outcomes and potential treatment-by-diabetes interaction was tested. Results: A total of 214/1,630 (13.1%) patients had DM. DM was an independent predictor of poor myocardial reperfusion as reflected by less frequent ST-segment elevation resolution ( 6570%) after PCI (OR 0.59, 95% CI 0.43\u20130.82, P < 0.01) and was an independent predictor of the composite 30-day outcomes of death/new myocardial infarction (MI)/urgent revascularization/definite stent thrombosis (ST) (OR 2.80, 95% CI 1.62\u20134.85, P < 0.01), new MI or definite acute ST (OR 2.46, 95% CI 1.08\u20135.61, P = 0.03), and definite ST (OR 10.00, 95% CI 3.54\u201328.22, P < 0.01). No significant interaction between pre-hospital ticagrelor vs in-hospital ticagrelor administration and DM was present for the clinical, electrocardiographic and angiographic outcomes as well as for thrombolysis in myocardial infarction major bleeding. Conclusions: DM remains independently associated with poor myocardial reperfusion and worse 30-day clinical outcomes. No significant interaction was found between pre-hospital vs in-hospital ticagrelor administration and DM status. Further approaches for the treatment of DM patients are needed. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01347580

Impact of presentation and transfer delays on complete ST-segment resolution before primary percutaneous coronary intervention: Insights from the ATLANTIC trial

Aims: The aim of this study was to identify predictors of complete ST-segment resolution (STR) pre-primary percutaneous coronary intervention (PCI) in patients enrolled in the ATLANTIC trial. Methods and results: ECGs recorded at the time of inclusion (pre-hospital [pre-H]-ECG) and in the catheterisation laboratory before angiography (pre-PCI-ECG) were analysed by an independent core laboratory. Complete STR was defined as 6570%. Complete STR occurred pre-PCI in 12.8% (204/1, 598) of patients and predicted lower 30-day composite MACCE (OR=0.10, 95% CI: 0.002-0.57, p=0.001) and total mortality (OR=0.16, 95% CI: 0.004-0.95, p=0.035). Independent predictors of complete STR included the time from index event to pre-H-ECG (OR=0.94, 95% CI: 0.89-1.00, p=0.035), use of heparins before pre- PCI-ECG (OR=1.75, 95% CI: 1.25-2.45, p=0.001) and time from pre-H-ECG to pre-PCI-ECG (OR=1.09, 95% CI: 1.03-1.16, p=0.005). In the pre-H ticagrelor group, patients with complete STR had a significantly longer delay between pre-H-ECG and pre-PCI-ECG compared to patients without complete STR (median 53 [44-73] vs. 49 [38.5-61] mins, p=0.001); however, this was not observed in the control group (in-hospital ticagrelor) (50 [40-67] vs. 49 [39-61] mins, p=0.258). Conclusions: Short patient delay, early administration of anticoagulant and ticagrelor if a long transfer delay is expected may help to achieve reperfusion prior to PCI. Pre-H treatment may be beneficial in patients with longer transfer delays, allowing the drug to become biologically active. ClinicalTrials.gov Identifier: NCT01347580

Assessment of Platelet REACtivity After Transcatheter Aortic Valve Replacement : The REAC-TAVI Trial

The REAC-TAVI (Assessment of platelet REACtivity after Transcatheter Aortic Valve Implantation) trial enrolled patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) pre-treated with aspirin + clopidogrel, aimed to compare the efficacy of clopidogrel and ticagrelor in suppressing high platelet reactivity (HPR) after TAVI. Current recommendations support short-term use of aspirin + clopidogrel for patients with severe AS undergoing TAVR despite the lack of compelling evidence. This was a prospective, randomized, multicenter investigation. Platelet reactivity was measured at 6 different time points with the VerifyNow assay (Accriva Diagnostics, San Diego, California). HPR was defined as (P2Y reaction units (PRU) ≥208. Patients with HPR before TAVR were randomized to either aspirin + ticagrelor or aspirin + clopidogrel for 3 months. Patients without HPR continued with aspirin + clopidogrel (registry cohort). The primary endpoint was non-HPR status (PRU <208) in ≥70% of patients treated with ticagrelor at 90 days post-TAVR. A total of 68 patients were included. Of these, 48 (71%) had HPR (PRU 273 ± 09) and were randomized to aspirin + ticagrelor (n = 24, PRU 277 ± 08) or continued with aspirin + clopidogrel (n = 24, PRU 269 ± 49). The remaining 20 patients (29%) without HPR (PRU 133 ± 12) were included in the registry. Overall, platelet reactivity across all the study time points after TAVR was lower in patients randomized to ticagrelor compared with those treated with clopidogrel, including those enrolled in the registry (p < 0.001). The primary endpoint was achieved in 100% of patients with ticagrelor compared with 21% with clopidogrel (p < 0.001). Interestingly, 33% of clopidogrel responder patients at baseline developed HPR status during the first month after TAVR. HPR to clopidogrel is present in a considerable number of patients with AS undergoing TAVR. Ticagrelor achieves a better and faster effect, providing sustained suppression of HPR to these patients. (Platelet Reactivity After TAVI: A Multicenter Pilot Study [REAC-TAVI]; NCT02224066