Discussion
Our case is demonstrating the tremendous effect of ARNI on the left ventricular function and remodeling that is noticed in the improvement of the ejection fraction together with the improvement in symptoms.
In 2016, the U.S. Food and Drug Administration (FDA) approved a new drug for the treatment of heart failure, the scientific evidence that has supported the approval of this new drug was mainly obtained from the results of the PARADIGM-HF trial which was a prospective comparison of ARNI with ACEI to determine impact on mortality and morbidity in patients with heart failure. (2)
Then, in 2019 another major trial was published by Velazquez EJ et al. that tested ARNI in patients with acute decompensated heart failure and they concluded that the initiation of ARNI in those patients led to a greater reduction in the NT-proBNP levels as well as less side effects like hypotension, hyperkalemia and angioedema. (5)
Many case reports and case series reports have been published with similar observation of the improved ejection fraction after using ARNI, one of them was published by Pandey et al. in 2017 where he included 60 HFrEF individuals and noticed the improvement of their EF from 27.3% to 37.5% after a period of one year (P<0.001). (6)
Later on, another prospective study was published by Bayard et al. in 2019, he included 52 patients and after only 3 months of follow up he noticed an improvement of the ejection fraction from 32.6 ± 5% to 36 ± 6% (p  < 0.0001) and this was also associated with improvement of the LV dimensions and volumes. (7)
One of the studies that aimed to evaluate changes in left ventricular ejection fraction (LVEF) in patients with heart failure and reduced LVEF treated with ARNI was recently conducted in Taiwan by Liu EW et al. where he enrolled 93 patients and prescribed ARNI as both first line and second line therapy and he found that the mean LVEF improved from 35 ± 6.1% to 50 ± 8.8% at 6 months use of sacubitril/valsartan (p < 0.001). (8)