Progression of myocardial fibrosis is the major determinant of heart failure hospitalization in patients undergoing transcatheter aortic valve implantation

Abstract Background Patient who are hospitalized for heart failure (HF) prior to transcatheter aortic valve implantation (TAVI) are associated with poor prognosis. In this study, we aimed to assess whether myocardial fibrosis (MF) in TAVI patients is strongly involved in prior heart failure hospitalization. Methods We performed a retrospective single-center study, including 93 patients who underwent cardiac biopsies before TAVI from December 2022 to December 2023. The extent of MF was assessed on Masson’s trichrome-stained tissue specimens, using a validated software "ImageJ". Results Prior hospitalization had significant association with BNP (HF hospitalization (+): 461.9[130.4-987.7] vs. HF hospitalization (-):125.3[78.2-228.6], p=0.0014) , aortic valve area index (AVAi) (0.43±0.02 vs. 0.51±0.01, p=0.002), left ventricular ejection fraction (LVEF) (54.4±2.8 vs. 67.2±1.6, p=0.0002), E/e’ (23.4±1.9 vs. 19.1±1.0, p=0.045), left atrial volume index (LAVI)(59.0±3.5 vs. 46.1±1.6, p=0.0013), global longitudinal strain (GLS) (13.2±1.0 vs. 15.7±0.5), and percent area of myocardial fibrosis(7.0[4.8-14.2] vs. 3.3[2.2-7.3], p=0.0002) Moreover, percent area of MF was the most reliable indicator (area under the curve: AUC= 0.75, p=0.0009) of prior heart failure hospitalization (figure 1) among HF parameters which include BNP (AUC=0.73, p<0.0001), AVAi (AUC=0.69, p=0.0024), LVEF(AUC=0.68,p=0.0005), E/e’ (AUC=0.63, p=0.051), LAVI (AUC=0.72, p=0.0022), GLS (AUC=0.65, p=0.035). Furthermore, the ROC curve analyses demonstrated that the best thresholds of LVEF and percent area of MF were 64.9% (60.9% sensitivity and 68.1% specificity) and 4.1% (91.7% sensitivity and 56.5% specificity) for heart failure hospitalization, respectively. When patients were divided into 4 groups according to LVEF 65% and percent area of myocardial fibrosis 4%, a stepwise increase in the proportion of heart failure hospitalization was found in the 4 groups (figure 2). Conclusions This study illustrates that extensive myocardial fibrosis was strongly associated with prior heart failure hospitalization in TAVI patients. Patients with advanced myocardial fibrosis due to aortic stenosis may benefit from earlier treatment with TAVI to prevent further progression of myocardial fibrosis.