Preprocedural Biomarkers of Inflammation and Fibrosis and Echocardiographic Markers of Myocardial Remodeling in New-Onset Conduction Disorders After Transcatheter Aortic Valve Implantation.

Background and Objectives: Conduction disorders (CDs) and permanent pacemaker implantation (PPI) remain among the most common complications after transcatheter aortic valve implantation (TAVI). Given their potential impact on long-term outcomes, improved preprocedural identification of patients at high risk for new-onset CDs is increasingly important. We investigated whether selected preprocedural inflammatory and fibrotic biomarkers, along with echocardiographic indices of regional myocardial remodeling, were associated with new-onset CDs after TAVI. Materials and Methods: This single-center prospective observational study included 112 patients with severe aortic stenosis undergoing TAVI. Peripheral blood samples were obtained within 24 h before TAVI for measurement of inflammatory and fibrotic biomarkers, including interleukin-6 (IL-6), C-reactive protein (CRP), CRP-to-albumin ratio (CAR), procalcitonin, ferritin, lactate dehydrogenase, and transforming growth factor-β1. The primary outcome was the occurrence of new-onset CDs during the index hospitalization or within three months after TAVI. Results: New-onset CDs occurred in 58 patients (51.8%). IL-6 showed the strongest association with the outcome in univariable analysis (OR per 1-SD increase, 9.55; 95% CI 3.00-30.40; p < 0.001), remained associated after adjustment for selected clinical and procedural predictors in exploratory models (adjusted OR 10.70; 95% CI 2.43-47.07; p = 0.002), and demonstrated the highest, although moderate, discriminatory performance among the evaluated biomarkers (AUC 0.730; 95% CI 0.637-0.823). CRP and CAR were higher in patients with CDs and were significant in univariable analysis, but showed weaker and less consistent adjusted associations. Among echocardiographic markers, AB strain ratio ≥ 2 was the most consistent imaging correlate in exploratory biomarker-echocardiographic models. Conclusions: Elevated preprocedural IL-6 was the biomarker most consistently associated with new-onset CDs after TAVI. These findings suggest that higher preprocedural IL-6 levels may reflect patient-specific susceptibility to new-onset CDs after TAVI and could have potential value as an adjunctive biomarker, alongside echocardiographic assessment, for preprocedural risk evaluation, with further validation required in larger prospective studies.