Aims: According to the current guidelines, the patent foramen ovale (PFO) is still considered a qualitative factor and, as a consequence, its closure is recommended just on the basis of its 'presence'.
Methods and results: In the year 2008, we evaluated 25 patients (mean age 62.7) with acute cerebrovascular event and 92 patients (mean age 27.3) suffering from migraine with aura. No PFO was reported in 79 patients. A venous-to-arterial circulation shunt had been shown in 38 patients (29 subjects with migraine and 9 subjects with prior stroke). According to the number of microbubbles arrived during the Valsava manoeuvre, we found: 25 small PFO, 6 moderate PFO, and 6 severe PFO. In the baseline population with migraine (n = 92), 32% (n = 29) had a PFO. A 'large' foramen was reported in approximately 9% of the migraine subjects. In the population with prior stroke (n=25), 9 patients (36%) had a PFO. A 'large' foramen was reported in 45% of the patients with ischaemic stroke. We found embryonic recesses in 13% (n = 4) of the patients with migraine and PFO (n=29) vs. 66% (n=6) of the patients with ischaemic stroke and PFO (P= 0.01).
Conclusion: It is possible to suppose that not all PFO have the same prognostic value. The evaluation of two anatomical characteristics can allow to identify those foramina at higher risk and, as a consequence, the patients who could have a major benefit from the closure.