Rationale Mice lacking the EF-hand Ca2+ sensor S100A1 display endothelial dysfunction due to distorted Ca2+ activated NO generation. Objective To determine the pathophysiological role of S100A1 in endothelial cell (EC) function in experimental ischemic revascularization. Methods and Results Patients with chronic critical lower limb ischemia (CLI) showed almost complete loss of S100A1 expression in hypoxic tissue. Ensuing studies in S100A1 knockout (SKO) mice subjected to femoral artery resection (FAR) unveiled insufficient perfusion recovery and high rates of autoamputation. Defective in vivo angiogenesis prompted cellular studies in SKO ECs and human ECs with siRNA-mediated S100A1 knockdown demonstrating impaired in vitro and in vivo proangiogenic properties (proliferation, migration, tube formation), and attenuated vascular endothelial growth factor (VEGF)- and hypoxia-stimulated eNOS activity. Mechanistically, S100A1 deficiency compromised eNOS activity in ECs both by interrupted stimulatory S100A1/eNOS interaction and PKC hyperactivation that resulted in inhibitory eNOS phosphorylation and enhanced VEGF-receptor 2 (VEGFR2) degradation with attenuated VEGF signaling. Ischemic SKO tissue recapitulated the same molecular abnormalities with insufficient in vivo NO generation. Unresolved ischemia entailed excessive VEGF accumulation in SKO mice with aggravated VEGFR2 degradation and blunted in vivo signaling through the proangiogenic PI3K/Akt/eNOS cascade. NO supplementation strategies rescued defective angiogenesis and salvaged limbs in SKO mice post-FAR. Conclusions Our study shows for the first time downregulation of S100A1 expression in patients with CLI and identifies S100A1 as critical for EC function in postnatal ischemic angiogenesis. These findings link its pathological plasticity in CLI to impaired neovascularization prompting further studies to probe S100A1’s microvascular therapeutic potential.

Background: The use of percutaneous left ventricular assist devices in patients with acute myocardial infarction complicated by cardiogenic shock (AMICS) is evolving. The aim of the study was to assess the long-term outcome of patients with AMICS depending on early initiation of Impella CP® support prior to a percutaneous coronary intervention (PCI). Methods: We retrospectively reviewed all patients who underwent PCI and Impella CP® support between 2014 and 2016 for AMICS at our institution. We compared survival to discharge between those with support initiation before (pre-PCI) and after (post-PCI) PCI. Results: A total of 73 consecutive patients (69±12 years old, 27.4% female) were supported with Impella CP® and underwent PCI for AMICS (34 pre-PCI vs. 39 post-PCI). All patients were admitted with cardiogenic shock, and 58.9% sustained cardiac arrest. Survival at discharge was 35.6%. Compared with the post-PCI group, patients in the pre-PCI group had more lesions treated ( p=0.03), a higher device weaning rate ( p=0.005) and higher survival to discharge as well as to 30 and 90 days after device implantation, respectively (50.0% vs. 23.1%, 48.5% vs. 23.1%, 46.9 vs. 20.5%, p < 0.05). Kaplan–Meier analysis showed a higher survival at one year (31.3% vs. 17.6%, log-rank p-value=0.03) in the pre-PCI group. Impella support initiation before PCI was an independent predictor of survival up to 180 days after device implantation. Conclusions: In this small, single-centre, non-randomized study Impella CP® initiation prior to PCI was associated with higher survival rates at discharge and up to one year in AMICS patients presenting with high risk for in-hospital mortality.

Rivaroxaban is a direct factor Xa inhibitor, which is rapidly absorbed in the upper gastrointestinal (GI) tract. In large trials, it has been shown to be effective and safe in VTE treatment. However, in these trials patients with morbid obesity were not reported and it is unknown if the standard dosage of 20 mg rivaroxaban is sufficient for bariatric patients, especially after bariatric surgery, which may impact the resorption of rivaroxaban. We report the case of a bariatric patient with high venous thromboembolism risk and instable INR after recent bariatric surgery, who was switched from Vitamin-K antagonists to rivaroxaban. After intake of 20 mg rivaroxaban, plasma concentration were repeatedly measured until 3 h after the second dose using a commercially available chromogenic aXa-assay. Furthermore, INR and aPTT were measured. Peak concentrations of 224.22 ng/ml were observed. After 6 h, plasma concentration decreased to 86.9 ng/ml and remained stable until 12 h (86.32 ng/ml). After 24 h, a trough level of 35.54 ng/ml was observed. The patients INR did immediately increase and remained significantly elevated throughout the day with a slow decrease. Since peak values of rivaroxaban plasma concentrations were in the expected range of published data, we conclude that resorption of rivaroxaban was immediate and not significantly impaired by bariatric surgery of the upper GI tract. Consequently, no dose adjustments seem to be necessary in this high-risk population.

Purpose: Heritable factors play an important etiologic role in connective tissue disorders (CTD) with vascular involvement, and a genetic diagnosis is getting increasingly important for gene-tailored, personalized patient management. Methods: We analyzed 32 disease-associated genes by using targeted next-generation sequencing and exome sequencing in a clinically relevant cohort of 199 individuals. We classified and refined sequence variants according to their likelihood for pathogenicity. Results: We identified 1 pathogenic variant (PV; in FBN1 or SMAD3) in 15 patients (7.5%) and ≥1 likely pathogenic variant (LPV; in COL3A1, FBN1, FBN2, LOX, MYH11, SMAD3, TGFBR1, or TGFBR2) in 19 individuals (9.6%), together resulting in 17.1% diagnostic yield. Thirteen PV/LPV were novel. Of PV/LPV-negative patients 47 (23.6%) showed ≥1 variant of uncertain significance (VUS). Twenty-five patients had concomitant variants. In-depth evaluation of reported/calculated variant classes resulted in reclassification of 19.8% of variants. Conclusion: Variant classification and refinement are essential for shaping mutational spectra of disease genes, thereby improving clinical sensitivity. Obligate stringent multigene analysis is a powerful tool for identifying genetic causes of clinically related CTDs. Nonetheless, the relatively high rate of PV/LPV/VUSnegative patients underscores the existence of yet unknown disease loci and/or oligogenic/polygenic inheritance.