ECG, clinical and novel CT-imaging predictors of necessary pacemaker implantation after transfemoral aortic valve replacement

Purpose Newly onset conduction disturbances with the need for permanent pacemaker (PPM) implantation remain the most common complication of transcatheter aortic valve replacement (TAVR). The objective was to evaluate the predictive value of clinical, ECG and new pre-procedural CT-imaging parameters for the requirement of PPM-implantation after TAVR. Methods 2105 consecutive patients receiving TAVR using a balloon expandable prosthesis (Sapien 3, Edwards Lifesciences, Irving, CA, USA) at our institution were enrolled. Patients receiving a valve-in-valve prosthesis, TAVR after surgical repair, with missing or non-diagnostic CT-scans, with pre-implanted PPM and after TAVR in mitral position were excluded. The most suitable classification model for the given dataset was first identified through benchmark testing and later applied for prediction analysis. Results 312 eligible patients requiring PPM implantation were compared to an age- matched control group of 305 patients not requiring PPM implantation. A scaled LASSO model allowed for most accurate prediction with an AUC of 0.70. Right bundle branch block was the strongest predictor (OR 2.739), followed by atrioventricular block 1° (OR 2.091), prosthesis diameter (OR 1.351), atrial fibrillation (OR 1.255), arterial hypertension (OR 1.215), coronary artery disease (1.070), the angle of ventricle axis and aortic root (OR 1.030), sinotubular junction height (OR 1.014) and the calcification of the left coronary cuspid (OR 1.007). Conclusions ECG- and clinical outperform imaging parameters in predicting PPM-implantation following TAVR. Right bundle branch block emerged as the most significant predictor overall, while the angle of ventricle axis and aortic root as a novel imaging-based predictor

Neutrophils can Promote Clotting via FXI and Impact Clot Structure via Neutrophil Extracellular Traps in a Distinctive Manner in vitro

Neutrophils and neutrophil extracellular traps (NETs) have been shown to be involved in coagulation. However, the interactions between neutrophils or NETs and fibrin(ogen) in clots, and the mechanisms behind these interactions are not yet fully understood. In this in vitro study, the role of neutrophils or NETs on clot structure, formation and dissolution was studied with a combination of confocal microscopy, turbidity and permeation experiments. Factor (F)XII, FXI and FVII-deficient plasmas were used to investigate which factors may be involved in the procoagulant effects. We found both neutrophils and NETs promote clotting in plasma without the addition of other coagulation triggers, but not in purified fibrinogen, indicating that other factors mediate the interaction. The procoagulant effects of neutrophils and NETs were also observed in FXII- and FVII-deficient plasma. In FXI-deficient plasma, only the procoagulant effects of NETs were observed, but not of neutrophils. NETs increased the density of clots, particularly in the vicinity of the NETs, while neutrophils-induced clots were less stable and more porous. In conclusion, NETs accelerate clotting and contribute to the formation of a denser, more lysis resistant clot architecture. Neutrophils, or their released mediators, may induce clotting in a different manner to NETs, mediated by FXI