Global Perspective on the Outcomes of Dietary Pattern and Nutrient-Based Interventions for Heart Failure: A Systematic Review of Randomized Controlled Trials

Background: Heart failure remains a leading cause of morbidity and mortality worldwide, with a rising prevalence in low- and middle-income countries. Although pharmacologic management is well established, dietary recommendations remain limited and poorly standardized. The objective of this study was to evaluate the impact of dietary interventions on heart failure outcomes, with a focus on global representation and sex stratification. Methods: This was a systematic review of randomized controlled trials that assessed the impact of dietary interventions on heart failure outcomes (signs and symptoms, quality of life, mortality, readmissions). Studies were identified through five electronic databases (Ovid MEDLINE, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and Web of Science). We initially searched for records published in English between 2012 and 2024 and updated our search to 2026 to reflect more recent literature. The risk of bias was assessed using the Joanna Briggs Institute tool for randomized controlled trials. Data were narratively synthesized by sex and World Bank country classification. Results: Of 3457 retrieved references, 21 met the inclusion criteria and were included in the synthesis. Sodium and fluid restriction were the most frequently studied dietary interventions (n = 9), with mixed findings. While some studies reported improvements in New York Heart Association functional class and quality of life, there was no consistent benefit on Brain Natriuretic Peptide levels, weight, hospital readmissions, emergency visits, or mortality. No randomized controlled trials were conducted in low- and lower-middle-income countries (LMICs), and only three studies conducted sex-stratified analyses. Conclusions: Sodium and fluid restriction showed limited and inconsistent evidence of benefits for heart failure outcomes, particularly in acute settings. This review suggests a critical need for high-quality dietary intervention trials in underrepresented populations, including LMICs and women, to inform equitable and effective heart failure management strategies worldwide.