Is There an Obesity Paradox for Outcomes in Atrial Fibrillation? A Systematic Review and Meta-Analysis of Non-Vitamin K Antagonist Oral Anticoagulant Trials

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#anticoagulants #atrial-fibrillation #embolism #hemorrhage #humans

Is There an Obesity Paradox for Outcomes in Atrial Fibrillation? A Systematic Review and Meta-Analysis of Non-Vitamin K Antagonist Oral Anticoagulant Trials

Proietti et al., 2017 | Stroke | Meta Analysis

Citation

Proietti Marco, Guiducci Elisa, ... Lip Gregory Y H. Is There an Obesity Paradox for Outcomes in Atrial Fibrillation? A Systematic Review and Meta-Analysis of Non-Vitamin K Antagonist Oral Anticoagulant Trials. Stroke. 2017-Apr;48(4):857-866. doi:10.1161/STROKEAHA.116.015984

Abstract

BACKGROUND AND PURPOSE: Obesity is a risk factor for all-cause and cardiovascular death but, despite this, an inverse relationship between overweight or obesity and a better cardiovascular prognosis in long-term follow-up studies has been observed; this phenomenon, described as obesity paradox, has also been found evident in atrial fibrillation cohorts. METHODS: We performed a systematic review on the relationship between body mass index and major adverse outcomes in atrial fibrillation patients. Moreover, we provided a meta-analysis of non-vitamin K antagonist oral anticoagulants (NOACs) trials. RESULTS: An obesity paradox was found for cardiovascular death and all-cause death in the subgroup analyses of randomized trial cohorts; however, observational studies fail to show this relationship. From the meta-analysis of NOAC trials, a significant obesity paradox was found, with both overweight and obese patients reporting a lower risk for stroke/systemic embolic event (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.66-0.84 and OR, 0.62; 95% CI, 0.54-0.70, respectively). For major bleeding, only obese patients were at lower risk compared with normal weight patients (OR, 0.84; 95% CI, 0.72-0.98). A significant treatment effect of NOACs was found in normal weight patients, both for stroke/systemic embolic event (OR, 0.66; 95% CI, 0.56-0.78) and for major bleeding (OR, 0.72; 95% CI, 0.54-0.95). Major bleeding risk was lower in overweight patients treated with NOACs (OR, 0.84; 95% CI, 0.71-1.00). CONCLUSIONS: There may be an obesity paradox in atrial fibrillation patients, particularly for all-cause and cardiovascular death outcomes. An obesity paradox was also evident for stroke/systemic embolic event outcome in NOAC trials, with a treatment effect favoring NOACs over warfarin for both efficacy and safety that was significant only for normal weight patients.

Key Findings

An obesity paradox was found for cardiovascular death and all-cause death in the subgroup analyses of randomized trial cohorts; however, observational studies fail to show this relationship. From the meta-analysis of NOAC trials, a significant obesity paradox was found, with both overweight and obese patients reporting a lower risk for stroke/systemic embolic event (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.66-0.84 and OR, 0.62; 95% CI, 0.54-0.70, respectively). For major bleeding,

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition See abstract

MeSH Terms

  • Anticoagulants
  • Atrial Fibrillation
  • Embolism
  • Hemorrhage
  • Humans
  • Obesity
  • Overweight

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: vitamin-k

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09