Accuracy of transcranial Doppler for the diagnosis of intracardiac right-to-left shunt: a bivariate meta-analysis of prospective studies

• Published in: JACC. Cardiovascular imaging Vol. 7; no. 3; p. 236
• Main Authors: Mojadidi, M Khalid, Roberts, Scott C, Winoker, Jared S, Romero, Jorge, Goodman-Meza, David, Gevorgyan, Rubine, Tobis, Jonathan M
• Format: Journal Article
• Language: English
• Published: United States 01.03.2014
• Subjects: Adult; Cerebrovascular Disorders - diagnostic imaging; Cerebrovascular Disorders - etiology; Contrast Media; Echocardiography, Transesophageal; Female; Foramen Ovale, Patent - complications; Foramen Ovale, Patent - diagnostic imaging; Foramen Ovale, Patent - therapy; Humans; Male; Microbubbles; Middle Aged; Predictive Value of Tests; Prognosis; Prospective Studies; Ultrasonography, Doppler, Transcranial; patent foramen ovale; right-to-left shunt; transcranial Doppler
• ISSN: 1876-7591; 1876-7591
• DOI: 10.1016/j.jcmg.2013.12.011

The aim of this meta-analysis was to determine the accuracy of transcranial Doppler (TCD) compared with transesophageal echocardiography (TEE) as the reference. Right-to-left shunting (RLS), usually through a patent foramen ovale (PFO), has been associated with migraine, cryptogenic stroke, and hypoxemia. With emerging observational studies and clinical trials on the subject of PFO, there is a need for accurate diagnosis of PFO in patients with these conditions, and those being considered for transcatheter closure. Although a TEE bubble study is the current standard reference for diagnosing PFO, the TCD bubble study may be a preferable alternative test for RLS because of its high sensitivity and specificity, noninvasive nature, and low cost. A systematic review of Medline, the Cochrane Library, and Embase was done to look for all the prospective studies assessing intracardiac RLS using TCD compared with TEE as the reference; both tests were performed with a contrast agent and a maneuver to provoke RLS in all studies. A total of 27 studies (29 comparisons) with 1,968 patients (mean age 47.8 ± 5.7 years; 51% male) fulfilled the inclusion criteria. The weighted mean sensitivity and specificity for TCD were 97% and 93%, respectively. Likewise, the positive and negative likelihood ratios were 13.51 and 0.04, respectively. When 10 microbubbles was used as the embolic cutoff for a positive TCD study, TCD produced a higher specificity compared with when 1 microbubble was used as the cutoff (p = 0.04); there was, however, no significant change in sensitivity (p = 0.29). TCD is a reliable, noninvasive test with excellent diagnostic accuracies, making it a proficient test for detecting RLS. TCD can be used as a part of the stroke workup and for patients being considered for PFO closure. If knowledge of the precise anatomy is required, then TEE can be obtained before scheduling a patient for transcatheter PFO closure.