Abstract and Keywords:

Aims

The total burden of myocardial fibrosis was recently proved to play an independent prognostic role in aortic stenosis patients after transcatheter aortic valve implantation (TAVI). However, total myocardial fibrosis summarizes various fibrosis subtypes that may represent fundamentally different and dynamic disease entities. Therefore, we aimed to assess the specific impact of fibrosis subtypes regarding sudden cardiac death (SCD) and death due to advanced heart failure (HFD) as the primary reasons for cardiovascular mortality in patients undergoing TAVI.

Methods and results

Fibrosis topography was assessed histologically using Masson’s trichrome staining in 156 patients with severe aortic stenosis using left ventricular biopsies obtained during TAVI intervention. Patients were characterized at baseline; median follow-up time was 672 days. Focal fibrosis was more dominant than the diffuse subtype. Depending on ROC analyses at 2 follow-up timepoints, both subtypes showed significant SCD predictivity 48 months post TAVI. However, diffuse fibrosis was the only significant SCD predictor in the early phase (12 months after TAVI). For HFD, we documented very few events in the first post-interventional year without significant histological predictors, focal fibrosis was the only subtype reaching significant predictivity at the late follow-up timepoint.

Conclusion

Histological evaluation of fibrosis topography hints at dramatically different paths for patients after TAVI. Therefore, it represents a valuable prognostic tool for TAVI patients and may help physicians tailoring individualized treatment concepts to optimize their postinterventional management.

Keywords

Aortic stenosis. Transcatheter aortic valve implantation. Endomyocardial biopsy. Myocardial fibrosis subtypes. Sudden cardiac death. Heart failure death.