Risk of atrial fibrillation in athletes: a systematic review and meta-analysis.
Newman W, Parry-Williams G, et al., Br J Sports Med. Epub Ahead of Print.
The risk of atrial fibrillation is greater in athletes than non-athletes.
Atrial fibrillation is a common cardiac arrhythmia in many populations. In many cases, atrial fibrillation can lead to more severe cardiac complications such as stroke. While some investigators have attempted to understand the relationship between exercise and the development of atrial fibrillation, the evidence is inconclusive.
Newman and colleagues completed a systematic review and meta-analysis of published studies to assess the risk of atrial fibrillation in an athletic population and understand how sport participation and cardiovascular disease factors affect atrial fibrillation.
According to the PRISMA statement, the researchers completed a comprehensive literature search to identify all potential studies. They identified a total of 2489 studies and then screened them for inclusion. The authors included studies that 1) reported the number of atrial fibrillation cases in athletes and a control group, 2) had a case-control or cohort study design, and 3) presented results with odd ratios and confidence intervals that they could extract or directly calculate. Ultimately, the authors included 13 studies in the systematic review and meta-analysis. They assessed study quality using the tool from CLARITY at McMaster University.
Of the 13 included studies, 7 were cohort studies and 6 were case-control. A total of 70,478 participants (63,662 control and 6,816 athletes) were included across all 13 studies. Five studies included participants with hypertension or diabetes. Overall, atrial fibrillation risk was 2.46 times higher in athletes than non-athletes. Interestingly, no difference in the risk of atrial fibrillation between athletes and non-athletes was found between studies that included hypertension or diabetes and studies that did not. One cautionary note is that the authors observed a difference in the odds ratios for atrial fibrillation between high- (lower odds ratio) and low-quality studies.
The authors demonstrated that while the risk of atrial fibrillation is higher in athletes than non-athletes, there remains a lack of high-quality research to base this conclusion. This makes it challenging to develop a “maximal safest ‘dose’ of exercise.” While direct conclusions cannot be reached from this study, the authors attempted to use a systematic review and meta-analysis to understand this phenomenon. Ultimately, we need more high-quality research to understand the relationship between athletic participation and atrial fibrillation risk.
This study suggests athletes may be at a greater risk for atrial fibrillation and hypertension and diabetes do not increase that risk. While the data is not of high quality, clinicians should be aware of the sign and symptoms of cardiac emergencies and remain vigilant. In addition, clinicians should also advocate for more advanced methods of cardiac screening such as ECG to prevent cardiac emergencies.
Questions for Discussion
Do you currently screen your athletes for cardiac abnormalities? How does this high-level study impact or change your understanding of the risk of atrial fibrillation in your population?
Written by: Kyle Harris
Reviewed by: Stephen Thomas
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