Abstract Background Heart failure (HF) is a clinical syndrome characterized by high mortality and morbidity. In 2016, Sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor (ARNI), was recommended as a new treatment option for HF in patients with HFrEF. In the 2021 European Society of Cardiology guidelines for treatment of HFrEF patients Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were introduced because they demonstrated significantly reduced HF events or cardiovascular (CV) mortality. Since ARNI and SGLT2i were introduced to treat HF, its therapeutic regimen has modernized from previous treatment with beta-blocker (BB) and angiotensin-converting enzyme inhibitor (ACEi)/angiotensin II receptor blocker (ARB) with mineralocorticoid receptor antagonist (MRA) as added-on in HF with reduced ejection fraction (HFrEF). Purpose This study is aimed to compare effectiveness of modern therapy including ARNI and SGLT2i with conventional heart failure treatment. Conventional HF treatment includes (BB, ACEi/ARB, with or without MRA) and modern heart failure treatment (BB, ACEi/ARB, MRA, SGLT2i or BB, ARNI, MRA with/without SGLT2i) in real-world. Methods This observational study (2013-2020), using the Swedish HF Registry, involved 20,849 HF patients. Patients received either conventional (BB, ACEi/ARB, with/without MRA, n=20,140) or modern (BB, ACEi/ARB, MRA, SGLT2i or BB, ARNI, MRA with/without SGLT2i, n=709) treatment at the index visit. The endpoints were all-cause and cardiovascular (CV) mortality. Results Modern HF therapy was associated with a significant 28% reduction in all-cause mortality compared to conventional HF treatment (adjusted HR [aHR]: 0.72 (95% CI 0.54 - 0.96), p=0.024), and had 33% reduced all-cause mortality (aHR: 0.67 (95% CI 0.48 - 0.94), p=0.019) within 2 years of index registration. Similarly, modern HF therapy was associated with a significant 62% reduction in CV mortality compared to conventional HF treatment (aHR: 0.38 (95% CI 0.21 - 0.68), p=0.0013). In addition, we found a 58% reduced CV mortality (aHR 0.42 (95% CI 0.22 - 0.79), p=0.0067) within 2 years of index registration. In the propensity score 1:1 matched cohort in which ARNI was included in the matching procedure, i.e., no ARNI was used in any of the two treatment groups and the effect of SGLT2i was the target assessment. The results were associated with a statistically significant risk reduction of 42% in all-cause mortality in the modern HF treatment group compared to the conventional treatment group (aHR: 0.58 (95% CI 0.36 - 0.94), p=0.028), and a 49% (aHR: 0.51 (95% CI 0.29 - 0.89), p=0.018) risk reduction within 2 years of index registration. Conclusion This study demonstrates that modern HF therapy in a real-world Swedish HF population is associated with a statistically significant risk reduction in all-cause and CV mortality, regardless of EF, sex, age, eGFR, and etiology of HF compared to conventional HF therapy.Central Illustration