Background

Transcranial Doppler (TCD) with agitated saline has been shown to be an alternative for the detection of right-to-left shunts (RLS) with similar diagnostic accuracies as transesophageal echocardiography (TEE). It is hypothesized that the addition of blood to agitated saline increases the sensitivity of TCD for the detection of RLS. The aim of this meta-analysis was to determine whether agitated saline with blood increases the sensitivity of TCD for the detection of RLS compared to agitated saline alone and other contrast agents.

Method

A systematic review of Medline, Cochrane, and Embase was performed to look for all 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.

Results

A total of 27 studies (29 comparisons) with 1,968 patients met the inclusion criteria. Of 29 comparisons, 10 (35%) used echovist contrast during TCD, 4 (14%) used a gelatin-based solution, 12 (41%) used agitated saline, and 3 (10%) utilized 2 different contrast agents. The addition of blood to agitated saline improved the sensitivity of TCD to 100% compared to agitated saline alone (96% sensitivity, P = 0.161), echovist (94% sensitivity, P = 0.044), and gelatin-based solutions (93% sensitivity, P = 0.041).

Conclusion

The addition of blood to agitated saline improves the sensitivity of TCD for the detection of RLS to 100% when compared to other conventional contrast agents; these findings support the addition of blood to agitated saline during TCD bubble studies.

OBJECTIVE: This study aimed to compare the safety and efficacy of third-generation P2Y12 inhibitors versus clopidogrel in combination with oral anticoagulation (OAC) with or without aspirin in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). METHODS: We performed a systematic review including both prospective and retrospective studies that compared dual and triple antithrombotic regimens for bleeding and major adverse cardiac events (MACE) in patients with AF undergoing PCI. We analysed rates of bleeding and MACE by P2Y12 inhibitor choice. Risk ratio (RR) 95% CIs were measured using the Mantel-Haenszel method. Where study heterogeneity was low (I2 <25%), we used the fixed effects model, otherwise the random effects model was used. RESULTS: A total of 22 014 patients were analysed from the seven studies included. Among patients treated with both OAC and P2Y12 inhibitor with or without aspirin, 90% (n=9708) were treated with clopidogrel, 8% (n=830) with ticagrelor, and 2% (n=191) with prasugrel. When compared with clopidogrel, use of ticagrelor (RR 1.36; 95% CI 1.18 to 1.57) and prasugrel (RR 2.11; 95% CI 1.34 to 3.30) were associated with increased rates of bleeding. Compared with clopidogrel, there were no significant differences in rates of MACE with ticagrelor (RR 1.03; 95% CI 0.65 to 1.62) or prasugrel (RR 1.49; 95% CI 0.69 to 3.24). CONCLUSION: Based on this meta-analysis, the use of clopidogrel is associated with a lower rate of bleeding compared with ticagrelor or prasugrel in patients with AF on OAC undergoing PCI.