- The study addressed whether weight loss is a safe and effective intervention for older patients with overweight and atrial fibrillation.
- This was a parallel-group, unblinded, randomized clinical trial involving 118 participants aged 60 to 85 years.
- The intervention group achieved a significant weight reduction of 9.7% versus 3.1% in controls (P < .001).
- The authors concluded that significant weight loss did not affect atrial fibrillation symptoms or burden in this population.
- Clinicians should note that weight loss in older patients with atrial fibrillation may not improve symptoms or cardiac remodeling.
Re-evaluating Weight Loss Strategies for Atrial Fibrillation in Older Adults
Atrial fibrillation (AF) is a prevalent arrhythmia, and its incidence is strongly linked to excess body weight, with obesity recognized as a significant risk factor for its development and progression [1, 2]. Current clinical guidelines advocate for weight loss as a therapeutic strategy for patients with obesity and AF, aiming to reduce symptom burden and improve outcomes [3, 4]. However, the evidence base for these recommendations largely stems from studies involving younger patient cohorts [5]. The physiological changes associated with aging, including altered metabolism and increased risk of frailty, raise questions about the generalizability of these findings to older adults [6]. Given the global rise in both AF and obesity, particularly within an aging population, understanding the precise role and impact of weight loss interventions in older patients with persistent AF is increasingly critical for guiding clinical practice [7, 8]. A new study now offers fresh insights into this important clinical question [9].
Addressing a Clinical Gap: Weight Loss in Older AF Patients
Excess body weight is a strong risk factor for atrial fibrillation (AF), a well-established clinical observation. Consequently, current clinical guidelines recommend weight loss for all patients with obesity and AF. However, the existing evidence supporting these weight loss recommendations primarily derives from studies involving younger patient populations. This creates a significant knowledge gap, as clinicians have expressed concerns that weight loss in older adults could potentially precipitate frailty, a critical consideration given the physiological changes associated with aging.
Recognizing this clinical uncertainty, the researchers designed the present study with a clear objective: to investigate whether weight loss constitutes a safe and effective intervention specifically for older patients who are overweight and have AF. This targeted approach aimed to provide evidence directly relevant to a demographic where the benefits and risks of weight loss interventions for AF had not been thoroughly evaluated.
Trial Design and Participant Characteristics
The study employed a parallel-group, unblinded, randomized clinical trial design, conducted across two hospitals in the United Kingdom. The trial period spanned from November 14, 2018, to April 25, 2025. Initial eligibility assessment involved approximately 1500 individuals who were undergoing electrical cardioversion for atrial fibrillation (AF). From this pool, approximately 500 individuals were invited to participate, based on specific criteria: an age range of 60 to 85 years, a body mass index (BMI) of 27 or greater, and the absence of any exclusion criteria. Of those invited, 119 provided informed consent to enter the trial, leading to a final cohort of 118 participants who were randomized.
These 118 participants were then allocated into two groups. The intervention arm consisted of 59 participants who received an 8-month low-calorie diet combined with a behavioral support program. The control arm also comprised 59 participants who received usual care. The researchers established the main outcome measure as the intention-to-treat analysis of the change in the Atrial Fibrillation Severity Scale (AFSS) symptom severity score, assessed at 8 months following randomization. The overall participant cohort (n = 118) had a mean age of 68 years (standard deviation, 6), and 33% of participants were female.
Achieving Weight Reduction Without Adverse Events
The intervention successfully induced significant weight loss in the participant cohort. At 8 months, the baseline-adjusted mean weight in the intervention group was 92.6 kg (standard error, 0.85), compared to 99.4 kg (standard error, 0.85) in the usual care control group. This difference was statistically significant (P < .001), with an estimated difference of -6.9 kg (95% CI, -9.2 to -4.5) between the groups. This translated to a substantial weight reduction of 9.7% in the intervention group, whereas the control group experienced a reduction of 3.1%, a difference also highly statistically significant (P < .001).
Crucially, the study found no compromise to patient safety during the intervention. No serious adverse events related to participation in the trial were reported in either the intervention or the control group. These findings indicate that in older patients with overweight and persistent atrial fibrillation, a structured low-calorie diet and behavioral support program can achieve significant weight loss at 8 months without introducing safety concerns.
Limited Impact on AF Symptoms and Other Clinical Outcomes
Despite the significant weight reduction achieved, the intervention did not translate into an improvement in the primary outcome measure: atrial fibrillation (AF) symptom severity. The study found no significant differences between the intervention and control groups in the Atrial Fibrillation Severity Scale (AFSS) symptom severity score at 8 months. The baseline-adjusted mean AFSS score was 7.9 (standard error, 0.84) in the intervention group compared to 8.9 (standard error, 0.84) in the control group. The between-group difference was -0.9 (95% CI, -3.3 to 1.4), with a P-value of .43, indicating no statistical significance.
Furthermore, the researchers observed no significant treatment effects on several key secondary clinical outcomes. This included physical performance, AF burden (the total amount of time a patient is in AF), cardiac imaging parameters (measures of heart structure and function, often reflecting cardiac remodeling), blood pressure, or lipid profile. The intervention also did not significantly affect the incidence of repeat cardioversion or AF ablation during the follow-up period. In summary, despite achieving substantial weight loss and demonstrating a favorable safety profile, the low-calorie diet and behavioral support program did not affect AF symptoms, AF burden, cardiac remodeling, or the need for further rhythm control interventions within the 8-month timeframe of the study.
References
1. Krishnan A, Sharma H, Yuan D, Trollope AF, Chilton L. The Role of Epicardial Adipose Tissue in the Development of Atrial Fibrillation, Coronary Artery Disease and Chronic Heart Failure in the Context of Obesity and Type 2 Diabetes Mellitus: A Narrative Review. Journal of Cardiovascular Development and Disease. 2022. doi:10.3390/jcdd9070217
2. Balan AI, Halațiu V, Scridon A. Oxidative Stress, Inflammation, and Mitochondrial Dysfunction: A Link between Obesity and Atrial Fibrillation. Antioxidants. 2024. doi:10.3390/antiox13010117
3. Cornier M. A review of current guidelines for the treatment of obesity. The American Journal of Managed Care. 2022. doi:10.37765/ajmc.2022.89292
4. Wass SY, Barnard J, Kim HS, et al. Upstream targeting for the prevention of atrial fibrillation: Targeting Risk Interventions and Metformin for Atrial Fibrillation (TRIM-AF)—rationale and study design. Journal of Interventional Cardiac Electrophysiology. 2024. doi:10.1007/s10840-024-01955-z
5. Hartmann‐Boyce J, Theodoulou A, Oke J, et al. Long-Term Effect of Weight Regain Following Behavioral Weight Management Programs on Cardiometabolic Disease Incidence and Risk: Systematic Review and Meta-Analysis. Circulation Cardiovascular Quality and Outcomes. 2023. doi:10.1161/circoutcomes.122.009348
6. Guo J, Huang X, Dou L, et al. Aging and aging-related diseases: from molecular mechanisms to interventions and treatments. Signal Transduction and Targeted Therapy. 2022. doi:10.1038/s41392-022-01251-0
7. Dye C, Cruz MD, Larsen TR, et al. A review of the impact, pathophysiology, and management of atrial fibrillation in patients with heart failure with preserved ejection fraction. American Heart Journal Plus Cardiology Research and Practice. 2023. doi:10.1016/j.ahjo.2023.100309
8. Herzog MJ, Müller P, Lechner K, et al. Arterial stiffness and vascular aging: mechanisms, prevention, and therapy. Signal Transduction and Targeted Therapy. 2025. doi:10.1038/s41392-025-02346-0
9. Sclafani M, Spartera M, Esmati Y, et al. Weight Loss in Older Patients With Persistent Atrial Fibrillation: The LOSE-AF Randomized Clinical Trial.. JAMA. 2026. doi:10.1001/jama.2026.5787