The extrinsic coagulation pathway is activated when circulating factor VII (FVII) gains access to tissue factor (TF) exposed as a consequence of vascular injury. Increasing evidence indicates that this TF-dependent activation of the coagulation plays an important role in the pathophysiology of intravascular thrombus formation. In the present study, we tested the effects of recombinant human, active site-blocked activated FVII (FVIIai) in a rabbit model of carotid artery thrombosis. Cyclic flow variations (CFVs), due to recurrent thrombus formation, were obtained in stenotic rabbit carotid arteries with endothelial injury. Carotid blood flow velocity was measured by a Doppler flow probe. After 30 minutes of CFVs, the animals received FVIIai (100 microg x kg(-1) x min(-1) intracarotid infusion for 10 minutes, n=9). If CFVs were abolished, animals were followed for 30 additional minutes, after which recombinant human activated FVII (FVIIa) was infused into the carotid artery (100 microg x kg(-1) x min(-1) for 10 minutes) to determine whether FVIIai could be displaced from TF by FVIIa, thus restoring CFVs. To establish the duration of action of FVIIai, an additional group of animals received FVIIai at the same dose as above, and after CFVs were inhibited, they were followed until CFVs were restored or for up to 6 hours. To determine whether CFVs could be restored by epinephrine after their abolition with FVIIai, increasing doses of epinephrine were administered to a third group of 6 animals. FVIIai abolished CFVs in 8 of 9 rabbits (P<.01). This effect was reversible, as FVIIa administration restored CFVs in all animals. Prothrombin times and activated partial thromboplastin times did not change significantly throughout the study. One single 10-minute infusion exerted complete antithrombotic effects for at least 6 hours, despite the fact that at this time point, plasma FVIIai levels were well below threshold concentrations. Epinephrine restored CFVs in 3 of 6 animals in which CFVs were inhibited by FVIIai. FVIIai exerts potent antithrombotic effects in this model; these effects were prolonged even after FVIIai was almost completely cleared from the circulation, probably as a result of the tight binding of FVIIai to TF. Thus, FVIIai might represent an antithrombotic substance of potential interest.

FK506 can act as a growth factor for VSMCs.

. Rapamycin antagonizes NF-B nuclear translocation activated by TNF-␣ in primary vascular smooth muscle cells and enhances apoptosis.

Transcatheter aortic valve implantation (TAVI) for aortic stenosis is becoming an appealing alternative to surgical aortic valve replacement in high-risk patients and to medical therapy for inoperable ones. Several new-generation TAVI devices have been recently introduced, but comparative analyses are lacking. We aimed to compare 1-month outcomes associated with such five leading new-generation TAVI devices exploiting data collected in the prospective observational RISPEVA (Registro Italiano GISE sull’impianto di Valvola Aortica Percutanea) Study. We queried the dataset of the ongoing RISPEVA study to retrieve baseline, procedural and 1-month outcome details of patients undergoing TAVI with Acurate, Evolut, Portico, Lotus, and Sapien3. Analysis was based on unadjusted and propensity score-adjusted methods. We included 1976 patients, 234 (11.8%) treated with Acurate, 703 (35.6%) with Evolut, 151 (7.6%) with Lotus, 347 (17.6%) with Portico, and 541 (27.4%) with Sapien3. Unadjusted analysis for baseline features highlighted several significant differences, and other discrepancies were found for procedural features. Despite these differences, device and procedural success were similarly high (ranging from 98.0% to 99.4%, p > 0.05). However, procedural valve migration appeared more common with Acurate (p = 0.007), and major bleeding with Sapien3 (p = 0.002). Unadjusted analysis for 1-month outcomes also highlighted significant differences in the composite of death, stroke, myocardial infarction, major vascular complication, major bleeding, or renal failure (favoring Portico, p < 0.001), major vascular complications (favoring Lotus, p < 0.001), renal failure (favoring Portico, p = 0.035), and permanent pacemaker implantation (favoring Acurate, p < 0.001). Propensity score-adjusted analyses showed lower rates of major adverse events with Evolut and Portico (p < 0.05), major vascular complications with Lotus and Portico (p < 0.05), renal failure with Sapien3 (p < 0.05) and permanent pacemaker implantation with Acurate (p < 0.05). In conclusion, new-generation TAVI devices have different profiles of early comparative safety and efficacy. These findings should be taken into account for individualized decision making and patient management.

These data suggest that retroviral-mediated transfection of the arterial wall with TFPI might represent an attractive approach for the treatment of thrombotic disorders.