Background: Patients with heart failure with mildly reduced ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF) experience a high burden of symptoms, physical limitations, and poor quality of life; improving health status is a key goal of management., Objectives: In a prespecified analysis of the DELIVER (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure) trial, we examine effects of dapagliflozin on health status using the Kansas City Cardiomyopathy Questionnaire (KCCQ)., Methods: The DELIVER trial randomized patients with symptomatic HFmrEF/HFpEF to dapagliflozin 10 mg or placebo. KCCQ was evaluated at randomization, 1, 4, and 8 months; KCCQ Total Symptom Score (TSS) was a key secondary endpoint. Patients were stratified by KCCQ-TSS tertiles; Cox models examined effects of dapagliflozin on clinical outcomes. We evaluated the effects of dapagliflozin on KCCQ-TSS, Physical Limitations (PLS), Clinical Summary (CSS), and Overall Summary (OSS) domains. Responder analyses compared proportions of dapagliflozin vs placebo-treated patients with clinically meaningful changes in KCCQ., Results: A total of 5,795 patients had baseline KCCQ (median KCCQ-TSS 72.9). The effects of dapagliflozin on reducing cardiovascular death/worsening HF appeared more pronounced in patients with greater baseline symptom burden (lowest-to-highest KCCQ-TSS tertile: HR: 0.70 [95% CI: 0.58-0.84]; 0.81 [95% CI: 0.65-1.01]; 1.07 [95% CI: 0.83-1.37]; P interaction = 0.026). Dapagliflozin improved KCCQ-TSS, -PLS, -CSS, and -OSS at 8 months (2.4, 1.9, 2.3, and 2.1 points higher vs placebo; P < 0.001 for all). Dapagliflozin-treated patients experienced improvements in KCCQ-TSS regardless of EF (P interaction = 0.85). Fewer dapagliflozin-treated patients had deterioration, and more had improvements in all KCCQ domains at 8 months., Conclusions: The clinical benefits of dapagliflozin in HFmrEF/HFpEF appear especially pronounced in those with greater baseline symptom impairment. Dapagliflozin improved all KCCQ domains and the proportion of patients experiencing clinically meaningful changes in health status. (Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure [DELIVER]; NCT03619213)., Competing Interests: Funding Support and Author Disclosures The DELIVER study was funded by AstraZeneca. Dr Kosiborod has received research grant support from AstraZeneca and Boehringer Ingelheim; has served as a consultant or on an advisory board for Alnylam, Amgen, Applied Therapeutics, AstraZeneca, Bayer, Boehringer Ingelheim, Eli Lilly, Esperion Therapeutics, Janssen, Lexicon, Merck (Diabetes and Cardiovascular), Novo Nordisk, Sanofi, Pharmacosmos, and Vifor Pharma; has received other research support from AstraZeneca; and has received honoraria from AstraZeneca, Boehringer Ingelheim, and Novo Nordisk. Dr Bhatt has previously received consulting fees from Sanofi Pasteur; and has been supported by the National Heart, Lung, and Blood Institute T32 postdoctoral training grant T32HL007604. Dr Claggett has received consulting fees from Amgen, Cardurion, Corvia, and Novartis. Dr Vaduganathan has received research grant support or served on advisory boards for American Regent, Amgen, AstraZeneca, Bayer AG, Baxter Healthcare, Boehringer Ingelheim, Cytokinetics, Lexicon Pharmaceuticals, Novartis, Pharmacosmos, Relypsa, Roche Diagnostics, Sanofi, and Tricog Health; has had speaker engagements with AstraZeneca, Novartis, and Roche Diagnostics; and participates on clinical trial committees for studies sponsored by Galmed, Novartis, Bayer AG, Occlutech, and Impulse Dynamics. Dr Lam is supported by a Clinician Scientist Award from the National Medical Research Council of Singapore; has received research support from Bayer and Roche Diagnostics; has served as a consultant or on the advisory board/steering committee/executive committee for Actelion, Alleviant Medical, Allysta Pharma, Amgen, AnaCardio AB, Applied Therapeutics, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Cytokinetics, Darma Inc, EchoNous Inc, Eli Lilly, Impulse Dynamics, Ionis Pharmaceutical, Janssen Research and Development LLC, Medscape/WebMD Global LLC, Merck, Novartis, Novo Nordisk, Prosciento Inc, Radcliffe Group Ltd, Roche Diagnostics, Sanofi, Siemens Healthcare Diagnostics and Us2.ai; and serves as cofounder and nonexecutive director of Us2.ai. Dr Hernandez has received research grants from American Regent, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Merck, Novartis, Somologic, and Verily; and has served as a consultant or on the Advisory Board for Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, Cytokinetics, Eidos, Intercept, Merck, and Novartis. Dr Martinez has received consultation fees and research grants from AstraZeneca, Baliarda, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Gador, Milestone, Novartis, Pfizer, and St Lukes University. Dr Inzucchi has served on clinical trial committees or as a consultant to AstraZeneca, Boehringer Ingelheim, Novo Nordisk, Lexicon, Merck, Pfizer, vTv Therapeutics, Abbott, and Esperion; and has given lectures sponsored by AstraZeneca and Boehringer Ingelheim. Dr Shah has received research grants from the National Institutes of Health (U54 HL160273, R01 HL107577, R01 HL127028, R01 HL140731, R01 HL149423), Actelion, AstraZeneca, Corvia, Novartis, and Pfizer; and has received consulting fees from Abbott, Actelion, AstraZeneca, Amgen, Aria CV, Axon Therapies, Bayer, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, Cardiora, Coridea, CVRx, Cyclerion, Cytokinetics, Edwards Lifesciences, Eidos, Eisai, Imara, Impulse Dynamics, GlaxoSmithKline, Intellia, Ionis, Ironwood, Lilly, Merck, MyoKardia, Novartis, Novo Nordisk, Pfizer, Prothena, Regeneron, Rivus, Sanofi, Sardocor, Shifamed, Tenax, Tenaya, and United Therapeutics. Dr de Boer has received research grants and/or fees from AstraZeneca, Abbott, Boehringer Ingelheim, Cardior Pharmaceuticals GmbH, Ionis Pharmaceuticals, Inc, Novo Nordisk, and Roche; and has had speaker engagements with Abbott, AstraZeneca, Bayer, Bristol Myers Squibb, Novartis, and Roche. Dr Jhund’s employer has been remunerated for his work on the DELIVER and DAPA-HF trials by AstraZeneca; has received consulting and speaker fees from Novartis, AstraZeneca, and Boehringer Ingelheim; has received research funding from Boehringer Ingelheim; and has received remuneration for clinical trial work from Novo Nordisk and Bayer. Dr Desai has received institutional grant support from Abbott, Alnylam, AstraZeneca, Bayer, and Novartis; and has received consulting fees from Abbott, Alnylam, AstraZeneca, Avidity, Axon Therapeutics, Bayer, Biofourmis, Boston Scientific, Cytokinetics, GlaxoSmithKline, Merck, Novartis, Parxel, Regeneron, Roche, and Verily. Dr Fang has received research grants from the National Institutes of Health; has served as a consultant for Novartis, Amgen, AstraZeneca, Boehringer Ingelheim/Lilly, Abbott, Capricor, Windtree, and LabCorp; and has provided support to the American Heart Association, National Institutes of Health, Heart Failure Society of America, and Heart Rhythm Society. Dr Josep Comin-Colet has received research grants from Novartis, Orion Pharma, AstraZeneca, Vifor Pharma, Bristol Myers Squibb; and has consulted for Novartis, Orion Pharma, AstraZeneca, Vifor Pharma, Bayer, Boehringer Ingelheim, Gilead, Menarini, and Pfizer. Dr Vardeny has received institutional research support for DELIVER from AstraZeneca; and has received institutional research support from Bayer. Drs. Lindholm, Wilderäng, and Bengtsson are employees and shareholders of AstraZeneca. Dr McMurray has received payments through Glasgow University for work on clinical trials; has received consulting fees and other activities from Alnylam, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Cardurion, Cytokinetics, Dal-Cor, GlaxoSmithKline, Ionis, KBP Biosciences, Novartis, Pfizer, and Theracos; has received personal lecture fees from the Corpus, Abbott, Hikma, Sun Pharmaceuticals, Medscape/Heart.Org, Radcliffe Cardiology, and Servier; and has served as Director of Global Clinical Trial Partners. Dr Solomon has received research grants from Actelion, Alnylam, Amgen, AstraZeneca, Bellerophon, Bayer, Bristol Myers Squibb, Celladon, Cytokinetics, Eidos, Gilead, GlaxoSmithKline, Ionis, Lilly, Mesoblast, MyoKardia, National Institutes of Health/National Heart, Lung, and Blood Institute, Neurotronik, Novartis, Novo Nordisk, Respicardia, Sanofi Pasteur, Theracos, and US2.AI; and has consulted for Abbott, Action, Akros, Alnylam, Amgen, Arena, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Cardior, Cardurion, Corvia, Cytokinetics, Daiichi-Sankyo, GlaxoSmithKline, Lilly, Merck, Myokardia, Novartis, Roche, Theracos, Quantum Genomics, Cardurion, Janssen, Cardiac Dimensions, Tenaya, Sanofi-Pasteur, Dinaqor, Tremeau, CellProThera, Moderna, American Regent, Sarepta, Lexicon, Anacardio, and Akros. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 The Authors. Published by Elsevier Inc. 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