AIMS: In 30-40% of patients with acute ischaemic stroke, the cause remains undefined (cryptogenic stroke). Contrast transoesophageal echocardiography (TEE) is considered the gold standard for patent foramen ovale (PFO) detection. Recently, however, cardiac magnetic resonance (CMR) has also been applied to detect PFO. In this study, we compared the diagnostic value of CMR and TEE in detecting PFO in a group of patients with apparently cryptogenic stroke.
METHODS AND RESULTS: Twenty-five patients (age 50 ± 13 years, 16 males) with apparently cryptogenic ischaemic stroke underwent contrast-enhanced TEE and contrast CMR for detection of possible PFO. Both imaging studies were performed during Valsalva manoeuvre. PFO grading results were assessed visually both for TEE and for CMR, according to the entity of contrast passage in the left atrium (grade 0 = no PFO; grades 1, 2, and 3 = mild, medium, and wide PFO, respectively). TEE detected PFO in 16 patients (64%). Contrast-enhanced CMR identified a PFO in 7 (44%) of these patients. TEE showed a grade 1 PFO in five patients, a grade 2 PFO in eight patients, and a grade 3 PFO in three patients. Of these patients, CMR failed to identify PFO in all five patients with a grade 1 PFO, in one patient with a grade 2 PFO, and one patient with grade 3 PFO according to TEE. None of the nine patients without PFO at TEE was shown to have a PFO at CMR. When compared with TEE, the present methodology of CMR had a sensitivity of 50%, specificity of 100%, negative predictive value of 31%, and a positive predictive value of 100%.
CONCLUSION: Our data suggest that TEE is the cornerstone imaging diagnostic test to detect and characterize PFO in patients with ischaemic stroke, and is shown to be better compared with the current CMR sequences.
- contrast CMR
- cryptogenic stroke