Discussion
In the present study conducted among patients with persistent or long-standing persistent AF: 1) the negative predictive value for thrombi using late-pCT was 100% as a reference of ICE, 2) all the CDs detected by late-pCT disappeared on subsequent late-pCT after several months under an altered anticoagulation therapy regime, and 3) the presence of residual contrast medium in the LAA on late-pCT was suggested to lower the blood velocity in the LAA to a value lower than 15cm/s.
In our study, CDs were observed on late-pCT in 2% of the patients, and despite the presence of CDs on early-pCT, 85% of the patients showed CD disappearance on late-pCT. In the patients without CDs on late-pCT, thrombus absence was confirmed on ICE performed from the LA. All the CDs observed on late-pCT vanished after the administration of altered anticoagulant therapy for several months under the same CT conditions.