Downregulation of the muscle-specific microRNA-1 (miR-1) mediates the induction of pathologic cardiac hypertrophy. Dysfunction of the gap junction protein connexin 43 (Cx43), an established miR-1 target, during cardiac hypertrophy leads to ventricular tachyarrhythmias (VT). However, it is still unknown whether miR-1 and Cx43 are interconnected in the pro-arrhythmic context of hypertrophy. Thus, in this study we investigated whether a reduction in the extent of cardiac hypertrophy could limit the pathological electrical remodeling of Cx43 and the onset of VT by modulating miR-1 levels. Wistar male rats underwent mechanical constriction of the ascending aorta to induce pathologic left ventricular hypertrophy (LVH) and afterwards were randomly assigned to receive 10mg/kg valsartan, VAL (LVH+VAL) delivered in the drinking water or placebo (LVH) for 12 weeks. Sham surgery was performed for control groups. Programmed ventricular stimulation reproducibly induced VT in LVH compared to LVH+VAL group. When compared to sham controls, rats from LVH group showed a significant decrease of miR-1 and an increase of Cx43 expression and its ERK1/2-dependent phosphorylation, which displaces Cx43 from the gap junction. Interestingly, VAL administration to rats with aortic banding significantly reduced cardiac hypertrophy and prevented miR-1 down-regulation and Cx43 up-regulation and phosphorylation. Gain- and loss-of-function experiments in neonatal cardiomyocytes (NCMs) in vitro confirmed that Cx43 is a direct target of miR-1. Accordingly, in vitro angiotensin II stimulation reduced miR-1 levels and increased Cx43 expression and phosphorylation compared to un-stimulated NCMs. Finally, in vivo miR-1 cardiac overexpression by an adenoviral vector intra-myocardial injection reduced Cx43 expression and phosphorylation in mice with isoproterenol-induced LVH. In conclusion, miR-1 regulates Cx43 expression and activity in hypertrophic cardiomyocytes in vitro and in vivo. Treatment of pressure overload-induced myocyte hypertrophy reduces the risk of life-threatening VT by normalizing miR-1 expression levels with the consequent stabilization of Cx43 expression and activity within the gap junction.

Background— Ticagrelor outperforms clopidogrel in preventing cardiovascular events in acute coronary syndrome. Despite the inclusion of a loading dose in the Platelet Inhibition and Patient Outcomes (PLATO) trial for all patients randomized to ticagrelor, it may not be necessary in patients receiving ongoing clopidogrel therapy. The aim of the present study was to assess whether a ticagrelor loading dose is associated with a further platelet inhibition during the switch from clopidogrel to ticagrelor in patients with acute coronary syndrome receiving ongoing antiplatelet treatment. Methods and Results— Fifty patients with acute coronary syndrome receiving aspirin and clopidogrel treatment were randomly assigned to a starting dose of ticagrelor (group 1, 90 mg; group 2, 180 mg). Platelet aggregation was measured using multiple electrode aggregometry and standard light transmission aggregometry just before the switch and at 2, 6, 24, and 72 hours. No relevant difference in platelet aggregation was observed between the 2 study arms at baseline ( P =0.256). Residual platelet aggregation was significantly reduced in both arms 2 hours after the first administration of ticagrelor ( P <0.001 for both), with no difference in aggregation between groups (multiple electrode aggregometry, 17.6±7.2 versus 18.1±6 U; P =0.281). Similar results were observed with LTA. Conclusions— Switching from clopidogrel to ticagrelor without a reloading dose is feasible, and it does not hinder platelet aggregation inhibition in patients with acute coronary syndrome. Further prospective studies are needed to assess the clinical relevance of our findings. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01795820.

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BackgroundUse of the non-vitamin K antagonist oral anticoagulants (NOACs) is endorsed by current guidelines for stroke prevention in patients with atrial fibrillation (AF). However efficacy and safety of NOACs in patients undergoing catheter ablation (RFCA) of AF has not been well established yet.ObjectivesTo perform a meta-analysis of all studies comparing NOACs and vitamin K antagonist oral anticoagulants (VKAs) in patients undergoing RFCA.Data SourcesStudies were searched for in PubMed and Google Scholar databases.Study Eligibility CriteriaStudies were considered eligible if: they evaluated the clinical impact of NOACs versus VKAs; they specifically analyzed the use of anticoagulants during periprocedural phase of RFCA; they reported clinical outcome data.Study Appraisal and Synthesis Methods25 studies were selected, including 9881 cases. The summary measure used was the risk ratio (RR) with 95% confidence interval (CI). The random-effects or the fixed effect model were used to synthesize results from the selected studies.ResultsThere was no significant difference in thromboembolic complications (RR 1.39; p=0.13). Bleeding complications were significantly lower in the NOACs-treated arm as compared to VKAs (RR=0.67, p<0.001). Interestingly, a larger number of thromboembolic events was found in the VKAs-treated arm in those studies where VKAs had been interrupted during the periprocedural phase (RR=0.68; p=ns). In this same subgroup a significantly higher incidence of both minor (RR=0.54; p=0.002) and major bleeding (RR=0.41; p=0.01) events was recorded. Conversely, the incidence of thromboembolic events in the VKAs-treated arm was significantly lower in those studies with uninterrupted periprocedural anticoagulation treatment (RR=1.89; p=0.02).LimitationsAs with every meta-analysis, no patients-level data were available.Conclusions and ImplicationsThe use of NOACs in patients undergoing RFCA is safe, given the lower incidence of bleedings observed with NOACs. On the other side, periprocedural interruption of VKAs and bridging with heparin is associated with a higher bleeding rate with no significant benefit on onset of thromboembolic events.

Background: A growing number of functional foods have been proposed to reduce cholesterol levels and the Portfolio Diet, which includes a combination of plant sterols, fibres, nuts, and soy protein, reduces low density lipoprotein cholesterol (LDL-C) from 20% to 30% in individuals with hyperlipidaemia. In this pilot study, the aim was to investigate whether a Mediterranean Diet incorporating a new and simple combination of cholesterol-lowering foods, excluding soy and nuts (namely the Portfolio-Mediterranean Diet), would reduce LDL-C levels, in the short-term, better than a Mediterranean Diet plus a sterol-enriched yogurt or a Mediterranean Diet alone. Methods: We retrospectively evaluated 24 individuals on a Portfolio-Mediterranean Diet and 48 matched individuals on a Mediterranean Diet with or without a sterol-enriched yogurt (24 each groups) as controls. Results: At follow-up (after 48±12 days), we observed an LDL reduction of 21±4, 23±4, and 44±4 mg/dL in the Mediterranean Diet alone, Mediterranean Diet plus yogurt and Portfolio-Mediterranean Diet respectively (P<0.001). Conclusion: A Portfolio-Mediterranean Diet, incorporating a new combination of functional foods such as oats or barley, plant sterols, chitosan, and green tea but not soy and nuts, may reduce LDL of 25% in the short term in individuals with hypercholesterolemia.