Background: There are few contemporary data on outcomes, costs, and treatment following a hospitalization for heart failure (hHF) in epidemiologically representative cohorts., Objectives: This study sought to describe rehospitalizations, hospitalization costs, use of guideline-directed medical therapy (GDMT) (renin-angiotensin system inhibitors, sacubitril/valsartan, beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter-2 inhibitors), and mortality after hHF., Methods: EVOLUTION HF (Utilization of Dapagliflozin and Other Guideline Directed Medical Therapies in Heart Failure Patients: A Multinational Observational Study Based on Secondary Data) is an observational, longitudinal cohort study using data from electronic health records or claims data sources in Japan, Sweden, the United Kingdom, and the United States. Adults with a first hHF discharge between 2018 and 2022 were included. The 1-year event rates per 100 patient-years (ERs) for death and rehospitalizations (with a primary diagnosis of heart failure (HF), chronic kidney disease [CKD], myocardial infarction, stroke, or peripheral artery disease) were calculated. Hospital health care costs were cumulatively summarized. Cumulative GDMT use was assessed using Kaplan-Meier estimates., Results: Of 263,525 patients, 28% died within the first year post-hHF (ER: 28.4 [95% CI: 27.0-29.9]). Rehospitalizations were mainly driven by HF (ER: 13.6 [95% CI: 9.8-17.4]) and CKD (ER: 4.5 [95% CI: 3.6-5.3]), whereas the ERs for myocardial infarction, stroke, and peripheral artery disease were lower. Health care costs were predominantly driven by HF and CKD. Between 2020 and 2022, use of renin-angiotensin system inhibitors, sacubitril/valsartan, beta-blockers, and mineralocorticoid receptor antagonists changed little, whereas uptake of sodium-glucose cotransporter-2 inhibitors increased 2- to 7-fold., Conclusions: Incident post-hHF rehospitalization risks and costs were high, and GDMT use changed little in the year following discharge, highlighting the need to consider earlier and greater implementation of GDMT to manage risks and reduce costs., Competing Interests: Funding Support and Author Disclosures EVOLUTION HF is funded by AstraZeneca. Dr Cleland was supported by a British Heart Foundation Centre of Research Excellence (grant number RE/18/6/34217). Dr Bozkurt has received consulting, advisory or research support from Abbott Vascular, Amgen, AstraZeneca, Baxter Healthcare Corporation, Boehringer Ingelheim, Bristol Myers Squibb, Cardurion, Liva Nova, Relypsa, Renovacor, Roche, Sanofi, scPharmaceuticals, and Vifor. Dr Savarese has received grants from AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Merck, Novartis, Pharmacosmos, and Vifor; and personal fees from AstraZeneca, Cytokinetics, Edwards Lifesciences, Medtronic, Novartis, Pharmacosmos, Roche, Laboratoires Servier, and Vifor. Drs Adamsson Eryd, Bodegård, Khordoc, and Zhang are employees of AstraZeneca. Dr Cleland has received grants and/or personal fees from Abbott Laboratories, Amgen, AstraZeneca, Bayer, Biopeutics, Boehringer Ingelheim, Bristol Myer Squibb, Idorsia, Johnson & Johnson, Medtronic, MyoKardia, NI Medical, Novartis, Pharmacosmos, Pharma Nord, Respicardia, Laboratoires Servier, Torrent Pharmaceuticals, Vifor, and VisCardia. Dr Thuresson is an employee of Statisticon, which has received funding from AstraZeneca. Dr Vardeny has received personal or institutional research support from AstraZeneca. Dr Lund has received grant support, lecture fees, and/or consulting fees from Abbott Laboratories, Alleviant, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Edwards Lifesciences, Lexicon Pharmaceuticals, Medscape, Merck Sharp & Dohme, MyoKardia, Novartis, OrionPharma, Pharmacosmos, Sanofi, and Vifor. Dr Kishi has reported that he has no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)