Activation of the CXCL12/CXCR4/ACKR3 axis is known to aid myocardial repair through ischemia-triggered hypoxia-inducible factor-1α (HIF-1α). To enhance the upregulation of HIF-1α, we administered roxadustat, a novel prolyl hydroxylase inhibitor (PHI) clinically approved by the European Medicines Agency 2021 for the treatment of renal anemia, with the purpose of improving LV function and attenuating ischemic cardiomyopathy. Methods: We evaluated roxadustat’s impact on HIF-1 stimulation, cardiac remodeling, and function after MI. Therefore, we analyzed nuclear HIF-1 expression, the mRNA and protein expression of key HIF-1 target genes (RT-PCR, Western blot), inflammatory cell infiltration (immunohistochemistry), and apoptosis (TUNEL staining) 7 days after MI. Additionally, we performed echocardiography in male and female C57BL/6 mice 28 days post-MI. Results: We found a substantial increase in nuclear HIF-1, associated with an upregulation of HIF-1α target genes like CXCL12/CXCR4/ACKR3 at the mRNA and protein levels. Roxadustat increased the proportion of myocardial reparative M2 CD206+ cells, suggesting beneficial alterations in immune cell migration and a trend towards reduced apoptosis. Echocardiography showed that roxadustat treatment significantly preserved ejection fraction and attenuated subsequent ventricular dilatation, thereby reducing adverse remodeling. Conclusions: Our findings suggest that roxadustat is a promising clinically approved treatment option to preserve myocardial function by attenuating adverse remodeling.

Purpose: The relevance of repetitive [^99mTc]Tc-DPD scintigraphy in wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) remains unclear. We investigated the impact of tafamidis on cardiac [^99mTc]Tc-DPD uptake, clinical, and laboratory markers at 6 and 12 months, and correlated 12 months [^99mTc]Tc-DPD uptake regression with survival. Methods: This single-center study enrolled 39 ATTRwt-CM patients. Upon treatment initiation with tafamidis, patients underwent follow-up [^99mTc]Tc-DPD scintigraphy, and clinical and laboratory evaluations at 6 months (n = 6) and 12 months (n = 13), or both (n = 20). Results: Tafamidis resulted in a significant decline in Perugini score (6 months p = 0.008, 12 months p < 0.001), and (semi-)quantitative [^99mTc]Tc-DPD uptake (total cardiac uptake: baseline 816 [522–933] cps, vs. 6 months 634 [502–734] cps, p = 0.003, vs. 12 months 523 [108–754] cps, p = 0.001). Clinical and laboratory improvements were observed (NYHA: 6 months p = 0.007, 12 months p = 0.033; NT-proBNP: baseline 2586 [1271–5561] ng/L, vs. 6 months 2526 [1109–4786] ng/L, p = 0.016, vs. 12 months 2340 [1411–4749] ng/L, p = 0.012). In Kaplan–Meier analysis, a decrease in right ventricular [^99mTc]Tc-DPD tracer uptake equal to or greater than the median value at 12 months (-30%) was associated with improved survival (log-rank p = 0.021). Conclusions: Tafamidis in ATTRwt-CM resulted in significant reductions of cardiac [^99mTc]Tc-DPD uptake, NYHA class, and cardiac biomarkers at 6 and 12 months. Regression of right ventricular [^99mTc]Tc-DPD uptake at 12 months was associated with improved survival.