Transcranial Doppler: Does Addition of Blood to Agitated Saline Affect Sensitivity for Detecting Cardiac...

Area of Science:

• Cardiology
• Neurology
• Medical Imaging

Background:

• Transcranial Doppler (TCD) with agitated saline is an established method for detecting right-to-left shunts (RLS).
• Transesophageal echocardiography (TEE) is a reference standard for RLS detection, with TCD showing comparable diagnostic accuracy.
• The hypothesis suggests that augmenting agitated saline with blood may increase TCD's sensitivity for RLS detection.

Purpose of the Study:

• To conduct a meta-analysis evaluating the sensitivity of TCD for RLS detection.
• To compare the efficacy of agitated saline with blood versus agitated saline alone and other contrast agents.
• To determine if adding blood to agitated saline improves TCD's diagnostic performance for RLS.

Main Methods:

• Systematic review of Medline, Cochrane, and Embase databases.
• Inclusion of prospective studies comparing TCD with TEE for intracardiac RLS detection.
• All studies utilized a contrast agent and a maneuver to provoke RLS.

Main Results:

• A total of 27 studies (29 comparisons) involving 1,968 patients were analyzed.
• Different contrast agents were used: echovist (35%), gelatin-based solutions (14%), and agitated saline (41%).
• Agitated saline with blood achieved 100% sensitivity, outperforming agitated saline alone (96%), echovist (94%), and gelatin-based solutions (93%).

Conclusions:

• The addition of blood to agitated saline significantly enhances TCD sensitivity for RLS detection to 100%.
• This combination proves superior to conventional contrast agents like echovist and gelatin-based solutions.
• Findings support the routine use of blood-augmented agitated saline in TCD bubble studies for RLS diagnosis.