Decompression Illness in Divers With or Without Patent Foramen Ovale : A Cohort Study.

ABSTRACT

BACKGROUND: In previous studies, the prevalence of patent foramen ovale (PFO) has been reported to be higher in scuba divers who experienced decompression illness (DCI) than in those who did not. OBJECTIVE: To assess the association between PFO and DCI in scuba divers. DESIGN: Prospective cohort study. SETTING: Tertiary cardiac center in South Korea. PARTICIPANTS: One hundred experienced divers from 13 diving organizations who did more than 50 dives per year. MEASUREMENTS Participants had transesophageal echocardiography with a saline bubble test to determine the presence of a PFO and were subsequently divided into high- and low-risk groups. They were followed using a self-reported questionnaire while blinded to their PFO status. All of the reported symptoms were adjudicated in a blinded manner. The primary end point of this study was PFO-related DCI. Logistic regression analysis was done to determine the odds ratio of PFO-related DCI. RESULTS: Patent foramen ovale was seen in 68 divers (37 at high risk and 31 at low risk). Patent foramen ovale-related DCI occurred in 12 divers in the PFO group (non-PFO vs. high-risk PFO vs. low-risk PFO 0 vs. 8.4 vs. 2.0 incidences per 10 000 person-dives; P = 0.001) during a mean follow-up of 28.7 months. Multivariable analysis showed that high-risk PFO was independently associated with an increased risk for PFO-related DCI (odds ratio, 9.34 [95% CI, 1.95 to 44.88]). LIMITATION: The sample size was insufficient to assess the association between low-risk PFO and DCI. CONCLUSION: High-risk PFO was associated with an increased risk for DCI in scuba divers. This finding indicates that divers with high-risk PFO are more susceptible to DCI than what has been previously reported and should consider either refraining from diving or adhering to a conservative diving protocol. PRIMARY FUNDING SOURCE Sejong Medical Research Institute.