New Study Reveals That TCD is Better Used to Detect PFO than TEE

Masha Dowell

doi:10.1177/155989771401009

Summary

About 25% of the world's population has been reported to have patent foramen ovale (PFO) or symptoms related to it, and they are at a greater risk of paradoxical embolisms [Kent DM, Thaler DE. Stroke 2010; Homma S, Sacco RL. Circulation 2005]. This article presents new research that revealed that transcranial doppler (TCD) ultrasound is superior to transesophageal echocardiography (TEE) for the detection of PFOs associated with higher stroke risk.

Ischemia
Neurology Clinical Trials
Neuroimaging
Imaging Modalities

Ischemia
Neurology Clinical Trials
Neuroimaging
Neurology
Imaging Modalities

About 25% of the world's population has been reported to have patent foramen ovale (PFO) or symptoms related to it, and they are at a greater risk of paradoxical embolisms [Kent DM, Thaler DE. Stroke 2010; Homma S, Sacco RL. Circulation 2005]. J. David Spence, MD, Robarts Research Institute of Western University, London, Ontario, Canada, presented new research that revealed that transcranial doppler (TCD) ultrasound is superior to transesophageal echocardiography (TEE) for the detection of PFOs associated with higher stroke risk.

Previous studies have focused on which PFO patients were most likely to have paradoxical embolisms. Clinical clues to paradoxical embolism have included pulmonic surges, dyspnea, tachycardia at onset, extended travel or sitting, previous deep vein thrombosis, and others. Small studies suggest that patients with paradoxical embolism had larger shunts, septal mobility [De Castro S et al. Stroke 2000], and atrial septal aneurysm [Mas J-L et al. N Engl J Med 2001]. More recent studies (the Northern Manhattan study and the ROPE study) have documented that neither septal aneurysm nor mobility predict strokes, however [Di Tullio MR et al. J Am Coll Cardiol 2013; Wesseler B et al. Circ Cardiovasc Imaging 2013].

In this trial, the research team studied the performance of TCD, in comparison with TEE, as it relates to the detection of high risk PFO. Of those patients (n=340) included in the research, 61.5% were women with a mean age of 53 years. All patients were confirmed to have had a cryptogenic stroke or were suspected of having a paradoxical embolism and were referred to the Urgent Transient Ischemic Attack (TIA) Clinic between the years of 2000 to 2013. Median follow-up was 420 days. At that time, the researchers discovered that 85 patients had a recurrent ischemic stroke or TIA. Occurrence of recurrent stroke or TIA was predicted by TCD shunt of Grade 3 or more (p=0.008; Figure 1), but not by TEE (p=0.6; Figure 2) [Spencer MP et al. J Neuroimaging 2004].

Figure 1.

Survival Free of Stroke/TIA by TCD Shunt Grade

TCD=transcranial Doppler; TIA=transient ischemic attack.Reproduced with permission from JD Spence, MD.

Figure 2.

Survival Free of Stroke/TIA by Right-Left Shunt on TEE

TEE=transesophageal echocardiography; TIA=transient ischemic attack.Reproduced with permission from JD Spence, MD.

In conclusion, because it was more sensitive for the diagnosis of PFO, TCD ultrasound was determined to be the better choice compared with TEE. The study additionally revealed that although TCD is superior to TEE for the ultimate detection of PFO.

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