Does testosterone therapy increase the risk of developing atrial fibrillation (a-fib)?

Testosterone Therapy and Risk of Atrial Fibrillation

Testosterone therapy may increase the risk of atrial fibrillation in older men, particularly those with high-normal testosterone levels, based on recent evidence. 1

Current Evidence on Testosterone and A-Fib

Recent Research Findings

• The most recent high-quality evidence from a 2024 study shows that high-normal testosterone levels are independently associated with increased risk of incident atrial fibrillation in healthy older men 1
• This finding is supported by data from the TRAVERSE trial (2023), which observed a higher incidence of atrial fibrillation in men receiving testosterone replacement therapy compared to placebo 2
• The timing of atrial fibrillation risk appears significant, with a median time-to-onset of 246 days for adverse cardiovascular events in patients on testosterone therapy 3

Conflicting Evidence

There are contradictory findings in the literature:

• A 2017 study found that normalization of testosterone levels after testosterone replacement therapy was associated with a decreased incidence of atrial fibrillation compared to men with non-normalized levels or no treatment 4
• Another study from 2018 reported that low testosterone levels were predictive for incident atrial fibrillation and ischemic stroke in men 5

Clinical Guidance for Testosterone Therapy

Cardiovascular Risk Assessment

• The American Urological Association (2018) recommends counseling patients that "it cannot be stated definitively whether testosterone therapy increases or decreases the risk of cardiovascular events" 6
• Prior to initiating testosterone therapy, patients should be informed about potential cardiovascular risks, including the possible increased risk of atrial fibrillation 6, 2

Monitoring Recommendations

• For patients on testosterone therapy, regular cardiovascular monitoring is essential:
  • Monitor for symptoms such as palpitations, shortness of breath, chest pain, dizziness, or transient loss of consciousness 6
  • Consider more frequent monitoring in patients with pre-existing cardiovascular risk factors 7
  • Target testosterone levels in the mid-normal range (450-600 ng/dL) to minimize potential risks 7

Special Considerations

• Older men (≥70 years) appear to be at higher risk for developing atrial fibrillation with testosterone therapy or with high-normal testosterone levels 1
• Patients with pre-existing cardiovascular disease or risk factors require more vigilant monitoring 7, 2
• Different testosterone formulations may carry different risks - injections may be associated with greater cardiovascular risk compared to gels due to fluctuating testosterone levels 6

Clinical Decision-Making Algorithm

1. Before initiating testosterone therapy:

   • Assess baseline cardiovascular risk factors
   • Consider age (higher risk in men ≥70 years)
   • Inform patient about potential increased risk of atrial fibrillation

2. During testosterone therapy:

   • Target testosterone levels to mid-normal range (450-600 ng/dL)
   • Monitor for symptoms of atrial fibrillation (palpitations, irregular heartbeat)
   • Perform regular cardiovascular assessments, especially during the first year

3. If atrial fibrillation is suspected:

   • Obtain ECG to confirm diagnosis
   • Consider temporarily suspending testosterone therapy
   • Evaluate risk-benefit ratio of continuing treatment

Conclusion

The relationship between testosterone therapy and atrial fibrillation remains complex. While testosterone replacement may be beneficial for men with symptomatic hypogonadism, the most recent evidence suggests an increased risk of atrial fibrillation, particularly in older men. Careful patient selection, appropriate dosing to achieve mid-normal testosterone levels, and vigilant monitoring are essential to minimize this risk.