Reversal of right ventricular pressure loading improves biventricular function independent of fibrosis in a rabbit model of pulmonary artery banding

Abstract

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Reversal of right ventricular pressure loading improves function independent of fibrosis

“…The findings by Fujioka et al. (2022) are similar to recent investigations in other models of PAB, which demonstrate similar results, even beyond the duration of de‐banding used in this study (Boehm et al., 2020; Verbelen et al., 2018). In preclinical and clinical studies, the impact of fibrosis has been hotly debated and suggests that the interpretation that fibrosis is a driver of dysfunction is incorrect and simplistic.…”

“…In accordance with the hypothesis of Fujioka et al. (2022), removal of pressure overload yields clear architectural benefits. After 6 weeks of PAB insufflation, the RV and LV from nDef animals exhibited changes compatible with ventricular remodelling as reflected by increased RV end‐systolic/end‐diastolic area (RVESA/RVEDA), LV systolic/diastolic eccentricity index (ESEI/EDEI), enlarged septal thickness and reduced LV filling volumes, all of which indicate remodelling.…”

“…The remarkable results shown by Fujioka et al. (2022) at the endpoint time of significant RV dysfunction suggest that an appropriately severe increase in RV pressure load was achieved. Whether this truly recreates the systemic response to RV afterload, including extracardiac organ dysfunction (congestive hepatopathy, renovascular congestion and splanchnic remodelling) was not assessed and is an important consideration in appropriate models of RV dysfunction and can hopefully be verified in subsequent studies (Boehm et al., 2020).…”

“…Therefore, in a recently published article in The Journal of Physiology , Fujioka et al. (2022) sought to investigate the role of afterload reduction in biventricular geometry, function and fibrosis in a rabbit model of pulmonary artery banding (PAB). The authors hypothesized that removal of RV pressure reduces biventricular fibrosis and thereby restores geometry and function.…”

“…The discrepancy between the irreversible process of fibrosis in the face of elevated afterload and the ability of the RV to recover function despite fibrosis is not well understood but holds significant clinical importance in conditions such as PAH. Therefore, in a recently published article in The Journal of Physiology, Fujioka et al (2022) sought to investigate the role of afterload reduction in biventricular geometry, function and fibrosis in a rabbit model of pulmonary artery banding (PAB). The authors hypothesized that removal of RV pressure reduces biventricular fibrosis and thereby restores geometry and function.…”