In patients with confirmed ST, OCT imaging identified an underlying morphological abnormality in 97% of cases.

Proprotein convertase subtilisin-kexin type 9 serine protease inhibition significantly improved lipid profiles and reduced the incidence of all-cause mortality compared with placebo but had a higher rate of neurocognitive adverse events. Thus, PCSK9 inhibitor therapy may serve as an alternative for patients with statin intolerance and for those who do not respond to other lipid reduction therapy.

The FRANCE TAVI registry provided reassuring data regarding trends in TAVR performance in an all-comers population on a national scale. Nonetheless, given that TAVR indications are likely to expand to patients at lower surgical risk, concerns remain regarding potentially life-threatening complications and pacemaker implantation. (Registry of Aortic Valve Bioprostheses Established by Catheter [FRANCE TAVI]; NCT01777828).

Summary.  Like all eukaryotic cells, platelets maintain plasma membrane phospholipid asymmetry in normal blood circulation via lipid transporters, which control transbilayer movement. Upon platelet activation, the asymmetric orientation of membrane phospholipids is rapidly disrupted, resulting in a calcium‐dependent exposure of the anionic phospholipid, phosphatidylserine (PS), at the outer platelet surface. This newly‐exposed PS surface is a major component of normal hemostasis because it supports platelet procoagulant function. Binding of blood clotting enzyme complexes to this negatively‐charged membrane surface allows a dramatic increase in the rate of conversion of zymogens to active serine proteases, which in turn produce a burst of thrombin leading to the formation of a fibrin clot and further platelet activation. Cells have the capacity to catalyze transbilayer phospholipid exchange via ATP‐requiring translocase enzymes (flippases and floppases), which control unidirectional phospholipid transport against a concentration gradient. They also use an energy‐independent, calcium‐dependent scramblase activity to govern the bidirectional exchange of phospholipids between the two leaflets of the bilayer; this activity is essential for PS exposure during platelet activation. Scramblase activity, biochemically characterized in the 1980s, is deficient in patients with Scott syndrome, a rare inherited bleeding disorder with defective platelet procoagulant activity. Despite considerable efforts, the platelet scramblase protein remained elusive for years but a significant advance has recently been made with the identification of TMEM16F, a membrane protein essential for calcium‐dependent PS exposure whose loss of function mutations are found in Scott syndrome. This review recalls historical aspects of platelet membrane asymmetry characterization, summarizes the mechanisms and roles of PS exposure following platelet activation and discusses the recent identification of TMEM16F and its significance in the scrambling process.

Between 2014 and 2016, the need for ECS remained stable around 0.7%. Left ventricular guidewire perforation and annular rupture were the most frequent causes, accounting for almost half of ECS cases. Half of the patients could be salvaged by ECS-nevertheless, 1 year of all-cause mortality was high even in those ECS patients surviving the in-hospital period.

Background: No randomized study powered to compare balloon-expandable (BE) with self-expanding (SE) transcatheter heart valve (THV) on individual endpoints after transcatheter aortic valve replacement (TAVR) has been conducted to date. Methods: From January 2013 to December 2015, the FRANCE-TAVI nationwide registry included 12,141 patients undergoing BE-THV (Edwards, n=8038) or SE-THV (Medtronic, n=4103) for native aortic stenosis (AS). Long-term mortality status was available in all patients (median 20 months, IQR:14-30). Patients treated with BE-THV (n=3910) were successfully matched 1:1 with 3910 patients treated with SE-THV by using propensity-score (25 clinical, anatomical and procedural variables) and by date of the procedure (within 3 months). The first co-primary outcome was the occurrence of paravalvular regurgitation (PVR)≥moderate and/or in-hospital mortality. The 2 nd co-primary outcome was 2-year all-cause mortality. Results: In matched-propensity analyses, the incidence of the 1st co-primary outcome was higher with SE-THV (19.8%) compared with BE-THV(11.9%; RR=1.68; 95%CI:1.46-1.91; p<0.0001). Each component of the outcome was also higher in SE-THV patients: PVR≥moderate (15.5% vs. 8.3%; RR=1.90; 95% CI:1.63-2.22; p<0.0001) and in-hospital mortality (5.6% vs 4.2%, RR=1.34; 95%CI:1.07-1.66; p=0.01). During follow-up, all-cause mortality occurred in 899 patients treated with SE-THV (2-year mortality was 29.8%) and in 801 patients treated with BE-THV (2-year mortality 26.6%; HR=1.17; 95% CI:1.06-1.29; p=0.003). Similar results were found using inverse probability of treatment weighting using propensity score analysis. Conclusions: The present study suggests that use of SE-THV was associated with a higher risk of PVR and higher in-hospital and 2-year mortality as compared with BE-THV. These data strongly support the need for a randomized trial sufficiently powered to compare head-to-head the latest generation of SE and BE-THV.

Aims The respective roles of oral anticoagulation or antiplatelet therapy following transcatheter aortic valve implantation (TAVI) remain debated. ATLANTIS is an international, randomized, open-label, superiority trial comparing apixaban to the standard of care. Methods and results After successful TAVI, 1500 patients were randomized (1:1) to receive apixaban 5 mg (2.5 mg if impaired renal function or concomitant antiplatelet therapy) (n = 749) twice daily, or standard of care (n = 751). Randomization was stratified by the need for chronic anticoagulation therapy. Standard-of-care patients received a vitamin K antagonist (VKA) (Stratum 1) or antiplatelet therapy (Stratum 2) if there was an indication for anticoagulation or not, respectively. The primary endpoint was the composite of death, myocardial infarction, stroke or transient ischaemic attack, systemic embolism, intracardiac or bioprosthesis thrombosis, deep vein thrombosis or pulmonary embolism, and life-threatening, disabling, or major bleeding over 1-year follow-up. The primary safety endpoint was major, disabling, or life-threatening bleeding. The primary outcome occurred in 138 (18.4%) and 151 (20.1%) patients receiving apixaban or standard of care, respectively [hazard ratio (HR) 0.92; 95% confidence interval (CI) 0.73–1.16] and there was no evidence of interaction between treatment and stratum (Pinteraction = 0.57). The primary safety endpoint was similar in both groups (HR 1.02; 95% CI 0.72–1.44). In Stratum 1 (n = 451), an exploratory analysis showed no difference for all endpoints between apixaban and VKA. In Stratum 2 (n = 1049), the primary outcome and primary safety endpoint did not differ, but obstructive valve thrombosis was reduced with apixaban vs. antiplatelet therapy (HR 0.19; 95% CI 0.08–0.46), while a signal of higher non-cardiovascular mortality was observed with apixaban. Conclusion After TAVI, apixaban was not superior to the standard of care, irrespective of an indication for oral anticoagulation.

To cite this article: Lhermusier T, van Rottem J, Garcia C, Xuereb JM, Ragab A, Martin V, Gratacap MP, Sié P, Payrastre B. The Syk-kinase inhibitor R406 impairs platelet activation and monocyte tissue factor expression triggered by heparin-PF4 complex directed antibodies. J Thromb Haemost 2011; 9: 2067-76.Summary. Background: Heparin-induced thrombocytopenia (HIT) is a rare but severe complication of heparin therapy in which immunoglobulin G (IgG) antibodies against the platelet factor 4-heparin complex activate platelets through the FccRIIA receptor. Clustering of FccRIIA initiates signaling cascades involving tyrosine kinases including the spleen tyrosine kinase (Syk). Moreover, besides the critical role of platelets, the expression of tissue factor (TF) by human monocytes triggered by HIT antibodies has been shown to contribute to the hypercoagulability and the thrombotic complications in HIT patients. Objectives: We investigated the effect of R406, a small molecule inhibitor of Syk developed as a potential treatment of autoimmune diseases, allergic disorders and B-cell related hematological malignancies, on FccRIIA-mediated platelet activation. To further assess the potential activity of Syk inhibitors in HIT treatment, the effect of R406 was also evaluated on HIT antibodies-induced expression of TF and procoagulant activity of monocytic cells. Results: We show that R406 is a potent inhibitor of platelet signaling and functions initiated by FccRIIA cross-linking by specific antibodies or by sera from HIT patients. Syk inhibition efficiently prevents FccRIIA-induced LAT phosphorylation and activation of phosphoinositide 3-kinase, Akt, phospholipase Cc2 and p38 MAP-kinase. As a consequence, FccRIIA-induced platelet aggregation, granule secretion and microparticles production are strongly inhibited by R406. Moreover, the Syk inhibitor efficiently impairs the expression of TF and the procoagulant activity of human monocytes triggered by HIT antibodies. Conclusion: Syk inhibitors may be of therapeutic interest in the treatment of HIT by reducing HIT antibodies-mediated platelet activation and monocyte procoagulant activity.