Second transcatheter closure for residual shunt following percutaneous closure of patent foramen ovale

The cause of ischemic stroke in younger adults is undefined in as many as 35 percent of patients. We studied the prevalence of patent foramen ovale as detected by contrast echocardiography in a population of 60 adults under 55 years old with ischemic stroke and a normal cardiac examination. We compared the results with those in a control group of 100 patients. The prevalence of patent foramen ovale was significantly higher in the patients with stroke (40 percent) than in the control group (10 percent, P less than 0.001). Among the patients with stroke, the prevalence of patent foramen ovale was 21 percent in 19 patients with an identifiable cause of their stroke, 40 percent in 15 patients with no identifiable cause but a risk factor for stroke, such as mitral valve prolapse, migraine, or use of contraceptive agents, and 54 percent in 26 patients with no identifiable cause (P less than 0.10). These results suggest that because of the high prevalence of clinically latent venous thrombosis, paradoxical embolism through a patent foramen ovale may be responsible for stroke more often than is usually suspected.

Patent foramen ovale and atrial septal aneurysm have been identified as potential risk factors for stroke, but information about their effect on the risk of recurrent stroke is limited. We studied the risks of recurrent cerebrovascular events associated with these cardiac abnormalities. A total of 581 patients (age, 18 to 55 years) who had had an ischemic stroke of unknown origin within the preceding three months were consecutively enrolled at 30 neurology departments. All patients received aspirin (300 mg per day) for secondary prevention. After four years, the risk of recurrent stroke was 2.3 percent (95 percent confidence interval, 0.3 to 4.3 percent) among the patients with patent foramen ovale alone, 15.2 percent (95 percent confidence interval, 1.8 to 28.6 percent) among the patients with both patent foramen ovale and atrial septal aneurysm, and 4.2 percent (95 percent confidence interval, 1.8 to 6.6 percent) among the patients with neither of these cardiac abnormalities. There were no recurrences among the patients with an atrial septal aneurysm alone. The presence of both cardiac abnormalities was a significant predictor of an increased risk of recurrent stroke (hazard ratio for the comparison with the absence of these abnormalities, 4.17; 95 percent confidence interval, 1.47 to 11.84), whereas isolated patent foramen ovale, whether small or large, was not. Patients with both patent foramen ovale and atrial septal aneurysm who have had a stroke constitute a subgroup at substantial risk for recurrent stroke, and preventive strategies other than aspirin should be considered.

To examine the association between patent foramen ovale (PFO) and atrial septal aneurysm (ASA) and stroke. Data from case-control studies that examined the relative frequency of PFO, ASA, or both, in all patients with ischemic stroke, cryptogenic stroke, and known stroke cause as well as control subjects were included. Trials were categorized by age, clinical comparison, and abnormality. Combined OR were calculated using fixed effect (FE) and random effect (RE) methods. Comparing patients with ischemic stroke with control subjects using RE, OR for all ages was 1.83 (95% CI, 1.25 to 2.66) for PFO (15 studies), 2.35 (95% CI, 1.46 to 3.77) for ASA (nine studies), and 4.96 (95% CI, 2.37 to 10.39) for PFO plus ASA (four studies). Homogeneous results were found within the group younger than age 55: using FE, OR was 3.10 (95% CI, 2.29 to 4.21) for PFO, 6.14 (95% CI, 2.47 to 15.22) for ASA, and 15.59 (95% CI, 2.83 to 85.87) for PFO plus ASA. For patients older than age 55, using FE, OR was 1.27 (95% CI, 0.80 to 2.01) for PFO, 3.43 (95% CI, 1.89 to 6.22) for ASA, and 5.09 (95% CI, 1.25 to 20.74) for PFO plus ASA. Comparing cryptogenic stroke with known stroke cause, heterogeneous results were derived from total group examination using RE: OR was 3.16 (95% CI, 2.30 to 4.35) for PFO (22 studies), 3.65 (95% CI, 1.34 to 9.97) for ASA (five studies), and 23.26 (95% CI, 5.24 to 103.20) for PFO plus ASA (two studies). In patients younger than age 55, using FE the OR was 6.00 (95% CI, 3.72 to 9.68) for PFO; only one study examined ASA or PFO plus ASA. In patients aged 55 years or older, three studies produced heterogeneous results for PFO: using RE, OR was 2.26 (95% CI, 0.96 to 5.31); no data were available on ASA prevalence. PFO and ASA are significantly associated with ischemic stroke in patients younger than 55 years. Further studies are needed to establish whether an association exists between PFO and ischemic stroke in those older than 55.