Objectives This study is aimed to compare the effectiveness of modern therapy including angiotensin receptor-neprilysin inhibitor (ARNI) and sodium-glucose cotransporter 2 inhibitors (SGLT2i) with conventional heart failure treatment in the real world. Background Since ARNI and SGLT2i were introduced to treat heart failure (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). However, a comparison between conventional and modern treatment strategies with drugs in combination has not been performed. 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 (adjusted HR [aHR], 0.72 (0.54-0.96); p = 0.024) and a significant 62% reduction in CV mortality (aHR, 0.38 (0.21-0.68); p = 0.0013) compared to conventional HF treatment. Similar results emerged in a sensitivity analysis using propensity score matching. The interaction analyses did not reveal any trends for EF (< 40% and >= 40%), sex, age (< 70 and >= 70 years), eGFR (< 60 and >= 60 ml/min/1.73 m(2)), and etiology of HF subgroups. Conclusion In this nationwide study, modern HF therapy was associated with significantly reduced all-cause and CV mortality, regardless of EF, sex, age, eGFR, and etiology of HF. [GRAPHICS] .