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Updated: Jun 13, 2025
Closure of a Patent Foramen Ovale PFO: An Intervention Sequence
Published on: December 23, 2022
Role of interatrial block in modulating cryptogenic stroke risk in patients with patent foramen ovale: a
Ye Du1, Yanxing Zhang1, Yangbo Xing2
1Department of Neurology, Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Shaoxing, 312000, China.
Insights
The interaction between interatrial block (IAB) and patent foramen ovale (PFO) is linked to cryptogenic stroke (CS). This study highlights that low-risk PFO significantly increases CS risk when co-occurring with IAB.
Area of Science:
- Cardiology
- Neurology
- Genetics
Background:
- Patent foramen ovale (PFO) and interatrial block (IAB) are recognized risk factors for cryptogenic stroke (CS).
- The specific interplay between PFO and IAB in the pathogenesis of CS remains incompletely understood.
Purpose of the Study:
- To investigate the interaction between PFO and IAB in patients experiencing cryptogenic stroke.
- To determine if the combination of PFO and IAB poses a greater risk for CS than either condition alone.
Main Methods:
- A case-control study involving 256 CS patients and 156 controls.
- IAB defined by P wave duration > 120 ms; PFO assessed via transesophageal echocardiography (no-PFO, low-risk PFO, high-risk PFO).
- Multiplicative and additive interaction analyses were employed to evaluate the combined effect of PFO and IAB on CS risk.
Main Results:
- A significant multiplicative interaction was found between IAB and low-risk PFO in CS (OR=3.653, P=0.037).
- Additive interaction analysis revealed that IAB accounted for 68.4% of the increased CS risk associated with low-risk PFO (P<0.001).
- High-risk PFO was independently associated with CS regardless of IAB status, while low-risk PFO was only associated with CS in the presence of IAB.
Conclusions:
- The interaction between IAB and PFO plays a significant role in cryptogenic stroke.
- This interaction is particularly pronounced in patients with low-risk PFO, suggesting a specific synergistic mechanism contributing to stroke risk.
Background:
The patent foramen ovale (PFO) and interatrial block (IAB) are associated with cryptogenic stroke (CS). However, the role of the interaction between PFO and IAB in CS remains unclear.
Methods:
This case-control study enrolled 256 patients with CS and 156 individuals without a history of stroke or transient ischemic attack. IAB was defined as P wave duration > 120 ms. PFO was evaluated by contrast transesophageal echocardiography, and classified as no-PFO, low-risk PFO and high-risk PFO. Multiplicative and additive interaction analysis were used to assess the interaction between PFO and IAB in CS.
Results:
Multiplicative interaction analysis unveiled a significant interaction between IAB and low-risk PFO in CS (OR for interaction = 3.653, 95% CI, 1.115-12.506; P = 0.037). Additive interaction analysis indicated that 68.4% (95% CI, 0.333-1.050; P < 0.001) of the increased risk of CS related to low-risk PFO was attributed to the interaction with IAB. The results were robust in multivariate analysis. However, but no significant multiplicative or additive interaction was observed between IAB and high-risk PFO. When stratified by IAB, high-risk PFO was associated with CS in both patients with IAB (OR, 4.186; 95% CI, 1.617-10.839; P = 0.003) and without IAB (OR, 3.476; 95% CI, 1.790-6.750; P < 0.001). However, low-risk PFO was only associated with CS in patients with IAB (OR, 2.684; 95% CI, 1.007-7.149; P = 0.048) but not in those without IAB (OR, 0.753; 95% CI, 0.343-1.651; P = 0.479).
Conclusion:
The interaction between IAB and PFO might play an important role in CS, particularly in cases with low-risk PFO.
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