Revisiting the Prevalence of Patent Foramen Ovale in Atrial Fibrillation Patients

Daher, Ghassan

Background
Patent Foramen Ovale (PFO) has been reported in 25-30% of the general population. The gold standard test for detecting PFO is a contrast enhanced transesophageal echocardiography (TEE). PFO presence can be confirmed during pulmonary vein isolation (PVI) procedure by passing the guidewire, dilator and sheath assembly through the foramen ovale, crossing the septum from the right to the left atrium without using a trans-septal needle for puncture. Our study reports the prevalence of PFO detected during PVI in 180 patients with atrial fibrillation (AF) who underwent PVI at Saint Louis University as compared to the prevalence detected during the pre-procedure TEE.

Methods
We retrospectively reviewed data from a cohort of 180 patients with AF who underwent PVI at Saint Louis University. Pre-PVI procedure, scheduled TEE reports were reviewed to assess for the presence of PFO and the PVI procedure reports were reviewed for confirmation.

Results
A total of 229 patients with AF who underwent PVI were reviewed. We were able to obtain complete records of 180 patients (55% male, mean population age 60.2 +/- 15.24). 102 of 180 patients had a PFO detected during the PVI procedure. This translates into a 56.7% prevalence of PFO in AF patients. Out of the 180 patients, 75 patients had a pre-PVI procedure TEE for whom PFO presence was reported in 18.7%. Given that the presence of PFO can be confirmed by our methods during PVI, the sensitivity and specificity of TEE in detection of PFO were 36.8% and 100%, respectively.

Conclusions
In our single-center cohort of AF patients, there was more than a two-fold increase in the detection rate of PFO during the PVI procedure in AF patients when compared to the general population. Our study reports a PFO prevalence of 18.7% using a pre-procedure TEE and 56.6% during the PVI procedure in AF patients undergoing PVI. Given that TEE is the gold standard for detection of PFO, our study suggests that the prevalence of PFO may be underestimated in our AF population.