Access site bleeding complications comparing oral anticoagulation therapy with NOACs and VKAs in patients with atrial fibrillation undergoing cardiac implantable device intervention

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation is frequent in patients undergoing cardiac implantable electronic device (CIED) intervention. Such population require oral anticoagulation therapy, which increases risk of procedure related bleeding. There is a lack on data on procedure-related bleeding outcome with non-vitamin K antagonist anticoagulants (NOACs) vs vitamin K antagonist anticoagulants (VKAs) in patients with AF undergoing CIED intervention.

Study purpose

Aim of the present stud was to evaluate whether NOACs have a safety benefit compared to VKAs in terms of fewer hemorrhagic complications at the site of CIED implant.

Methods

Consecutive AF patients receiving NOACs or VKAs at the time of CIED procedure were included in this observational, retrospective, monocentric investigation. Primary endpoint was the incidence of post-intervention clinically significant pocket hematoma. Multivariate analysis was performed to investigate the association between covariates and the primary endpoint.

Results

A total of 311 patients were enrolled, 146 on NOACs and 165 on VKAs. The incidence of pocket hematoma was 3.4% in the NOAC vs 13.3% in the VKA group (p=0.002) (Figure 1). Primary outcome-free survival at 30-days was 96.6 % in patients on NOACs and 86.0% in those on VKAs (p=0.019) (Figure 2). Multivariate analysis, adjusted by propensity-score calculation of inverse-probability-weighting, showed a significantly lower occurrence of pocket hematoma in patients receiving NOACs vs VKAs (HR 0.35, 95% CI 0.13-0.96, p=0.042). Such NOACs benefit was confirmed vs patients on VKAs without peri-procedural bridging with low-molecular weight heparin (HR 0.34, 95% CI 0.11-0.99, p=0.048). The incidence of pocket infection, surgical pocket evacuation, ischemic events and major bleeding complications at 30 days (secondary endpoints) was similar in the two groups.

Conclusion

Among patients with AF undergoing implantable cardiac defibrillator or pace-maker intervention, the use of NOACs vs VKAs is associated with significant reduction of post-procedural pocket hematoma, regardless of bridging with low molecular-weight heparin in the VKA group.

Comparison of infective complications with two different antibiotic prophylaxis at two-years follow up in patients undergoing cardiac implantable electronic device procedure: a prospective study

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac implantable electronic device (CIED) infective complications are associated with high morbidity and mortality. Selection of proper antibiotic prophylaxis therapy is mandatory, as it can decrease the infective risk.

Purpose of the Study

Aim of the present study was to compare two different antibiotic strategy in term of procedural-related infective complications in a two-years follow-up.

Material and Methods

Patients undergoing CIED procedure (implant, replacement, or revision), with cefuroxime antibiotic prophylaxis during 2009 were consecutively enrolled as study group, with the purpose to have a long follow-up available (10 years). Patients undergoing CIED procedure (implant, replacement, or revision), with cefazolin antibiotic prophylaxis during 2020 were consecutively enrolled as control group. Primary endpoint was the evaluation of infective complications in the first 2 years follow-up (pocket infection, endocarditis and infective complication requiring CIED complete extraction). Multivariate analysis was performed to evaluate association between covariates resulted significantly different between the two study groups and study endpoint. Long-term follow-up incidence of infective complications was evaluated in the cefuroxime group.

Results

340 patients were enrolled in the cefuroxime prophylaxis group and 239 patients in the cefazolin prophylaxis group. There was no significative difference of median age between the two study groups. Patients in the cefazolin prophylaxis group compared to the cefuroxime group showed higher rate of diabetes (33.1% vs 22.1%, p=0.003), dyslipidemia (46.4% vs 36.5%, p=0.02) and higher rate of antiplatelet (45.2% vs 40.6%, p<0.001) and anticoagulation therapy (36.8% vs 31.8%, p<0.001) (Figure 1). ICD and CRT implant was more frequent in patients in the cefazolin group (33.3% vs 25.06%, p=0.05) (Figure 2). There was no significant difference of the primary endpoint in the two study groups: pocket infection (cefazolin group n=4, 1.7%, vs cefuroxime group n=5, 1.5%, p=0.85), endocarditis (cefazolin group n=1, 0.4%, vs cefuroxime group n=1, 0.3%, p=0.8) and infection requiring complete device extraction (cefazolin group n=2, 0.8%, vs cefuroxime group n=2, 0.6%, p=0.95). At multivariate analysis, there was an observed trend in reduction of infective complications in patients undergoing pacemaker (odds ratio 0.23) and CRT (odds ratio 0.82) implant.

At 10 years follow-up, 11 (3.2%) infective procedure-related complications were recorded in the cefuroxime group, 5 pocket infection, 5 pocket infection with erosion and 1 endocarditis.

Conclusion

Cefazolin antibiotic prophylaxis is effective as cefuroxime prophilaxis in reducing CIED procedure-related infections, even if patients in the cefazolin group showed higher prevalence of comorbidities and more complex device procedure (ICD and CRT implant).

Lack of NO Formation Is Involved in the Vasodilative Response to Contrast Media

Intravascular injection of angiographic contrast media results in peripheral vasodilation and hypotension. The mechanisms underlying these hemodynamic changes are not entirely clear. We hypothesized that increased formation of nitric oxide (NO) could be involved in the vasodilatory response to contrast media. To address this assumption we have investigated whether N(G)-monomethyl-L-arginine (L-NMMA, 200 mg/kg) and N(G)-nitro-L-arginine methyl ester (L-NAME, 50 mg/kg), two specific NO formation inhibitors, can abolish the hypotensive response to intravascular injection of isopaque amin (1 g/kg), a contrast medium, as well as bradykinin (10 µg/kg), a NO-dependent vasodilator, in anaesthetized normotensive rats. In rats before pretreatment with L-NMMA and L-NAME, the absolute values of the average fall in mean arterial pressure (MAP) induced by intravascular injection of isopaque amin and bradykinin were 21.3 +/- 2.1 and 37.2 +/- 4.4 mmHg, respectively. Pretreatment with L-NMMA and L-NAME failed to affect the hypotensive response to isopaque amin; by administering isopaque amin in rats pretreated with L-NMMA and L-NAME the absolute values of the average fall in MAP were 25.6 +/- 4.9 and 23.4 +/- 3.9 mmHg, respectively, similar to the average fall in MAP before treatment with NO formation inhibitors. In contrast, the hypotensive response to bradykinin was significantly inhibited; by administering bradykinin in rats pretreated by L-NMMA and L-NAME, the absolute values of the average fall in MAP were 10.2 +/- 2.8 and 7.2 +/- 2.2 mmHg, respectively, much less than the average fall in MAP before treatment with NO formation inhibitors. We conclude that intravascular injection of isopaque amin causes reduction in systemic arterial pressure. However, this vasodilative effect seems unrelated majorly to augmented endothelium-derived NO formation.

[Bifurcation stenting of unprotected common trunk: a case report and review of the literature]

Left main disease is the most severe form of atherosclerotic heart disease, with severe prognostic implications in the short-medium term. The traditional therapeutic approach has been surgical, with placement of bypass grafts both on the LAD and the circumflex artery. Published experience with the percutaneous approach to left main disease has been disappointing because of acute procedural problems and poor long-term outcome. On the other hand, a review of the literature shows a strong negative selection of patients offered PTCA of left main-stem lesions: most published series are composed of extremely high-risk patients, often in cardiogenic shock or with severe extracardiac multisystem disease, with a prohibitive surgical risk and an inherently poor acute and mid-term prognosis. We describe such a patient, a 77-year-old woman with end-stage renal disease on hemodialysis, who developed unstable angina due to distal critical left main disease, with involvement of the origin of both the LAD and the circumflex branch. Angina did not stabilize with medical therapy; the patient was denied surgery because of a prohibitively high surgical risk. A bifurcation stenting procedure was performed with no acute complications, a satisfactory one-month angiographic follow-up and no recurrence of angina until the death of the patient 4 months after the procedure for extracardiac reasons. As indicated by a recent paper by M. Leon, we likewise suggest that left main disease (especially in its simpler proximal variants) may actually be a good target for state-of-the-art transcatheter interventions, including primary stenting, under close angiographic follow-up and careful positive (instead of negative) selection of patients.

Molecular and cellular aspects of induced thymus development in recombinase-deficient mice

Thymus development and microenvironment organization require stage- and site-specific cross-talk between thymocyte and stroma. In this study we have used recombinase-activating gene-deficient (RAG-2(-/-)) mice to analyze regulated gene expression both in thymocytes and stromal cells following injection of anti-CD3 monoclonal antibodies as inducer of thymus development. We show that IFN-gamma, TNF-alpha and lymphotactin are transcriptionally regulated in thymocytes, whereas cytoskeletal keratin 14, IL-1alpha and TNF-alpha are regulated in the stroma, quantitatively reproducing the variations associated with beta selection of thymocytes. In addition, RAG-2(-/-) thymus development is associated with entry of epithelial cells into the cell cycle. The histochemical evidence that expanded RAG-2(-/-) thymus becomes undistinguishable from wild-type cortex further suggests that cross-talk phenomena occurring during beta selection of thymocyte are reproduced in this system.

Surface expression and functional competence of CD3-independent TCR zeta-chains in immature thymocytes

In recombinase-deficient (RAG-2-/-) mice, double-negative thymocytes can be stimulated to proliferate and differentiate by anti-CD3 Abs. CD3 molecules are expressed on the surface of these cells in association with calnexin. In this study, we show that zeta-chains can be recovered as phosphorylated proteins in association with phosphorylated ZAP-70 from anti-CD3-stimulated RAG-2-/- thymocytes, even though they are not demonstrably associated with the CD3/calnexin complex. The lack of a physical association of zeta dimers with the CD3 complex in RAG-2-/- thymocytes and also in a pre-TCR-expressing cell line, as well as the efficient association of zeta dimers with ZAP-70 in the RAG-2-/- thymocytes, suggest that these zeta-chain dimers could contribute to pre-TCR signaling. This idea is supported by the finding that in RAG-2-/- zeta-deficient thymocytes, ZAP-70 and p120cbl were only weakly phosphorylated.

GKLF in thymus epithelium as a developmentally regulated element of thymocyte-stroma cross-talk

Gut-enriched Krüppel-like factor (GKLF) is a transcriptional regulator expressed in differentiated epithelia. We identified GKLF transcript as a regulated element in thymic epithelium of recombinase-deficient mice during thymus development induced by anti-CD3 antibody injection. This treatment recapitulates the organogenetic process depending on productive rearrangement of T cell receptor (TCR) beta gene with thymocytes expansion and acquisition of the CD4+8+ double positive phenotype. In wildtype mice, GKLF is expressed very early in embryogenesis and becomes intensely up-regulated in thymus epithelium at day 18 of gestation when TCR beta expressing cells have selectively expanded and express both CD4 and CD8. The results presented here suggest that thymocytes may regulate GKLF transcriptionally in the cortical epithelium at the developmental check-point controlled by TCR beta gene rearrangement. Furthermore, GKLF expression in hematopoietic stroma might suggest the thus far uncharacterised participation of this factor in hematopoiesis.

Epithelial V-like antigen (EVA), a novel member of the immunoglobulin superfamily, expressed in embryonic epithelia with a potential role as homotypic adhesion molecule in thymus histogenesis

Thymus development depends on a complex series of interactions between thymocytes and the stromal component of the organ. To identify regulated genes during this codependent developmental relationship, we have applied an RNA fingerprinting technique to the analysis of thymus expansion and maturation induced in recombinase-deficient mice injected with anti-CD3 antibodies. This approach led us to the identification of a gene encoding a new member of the immunoglobulin superfamily, named epithelial V-like antigen (EVA), which is expressed in thymus epithelium and strongly downregulated by thymocyte developmental progression. This gene is expressed in the thymus and in several epithelial structures early in embryogenesis. EVA is highly homologous to the myelin protein zero and, in thymus-derived epithelial cell lines, is poorly soluble in nonionic detergents, strongly suggesting an association to the cytoskeleton. Its capacity to mediate cell adhesion through a homophilic interaction and its selective regulation by T cell maturation might imply the participation of EVA in the earliest phases of thymus organogenesis.