Thrombi in left atrium can be detected with cardiac MRI

Kitkungvan et al report in the J Am CollCardiovascular Imaging that left atrial (LA) and left atrial appendage (LAA) thrombi can be detected with cardiac MRI (CMR) – without the need of a trans-esophageal echocardiogram (TEE) – before pulmonary vein isolation (PVI) is performed.

They studied 261 patients with congestive heart failure, hypertension, diabetes mellitus, stroke/transient ischemic attack, vascular disease, with CMR and TEE for evaluation of pulmonary venous anatomy before PVI. LA and LAA thrombi were evaluated by using CMR as follows: 1) cine-CMR; 2) contrast-enhanced magnetic resonance angiography; and 3) equilibrium phase delayed enhancement (DE) CMR with a long inversion time (TI) of 600 ms (long TI DE-CMR).

CMR and TEE were performed within 1.3 ± 2.3 days. LA/LAA thrombi were discovered in 9 patients (3.5%) by using TEE. Among the CMR techniques performed, long TI DE-CMR had the highest diagnostic accuracy (99.2%), sensitivity (100%), and specificity (99.2%), followed by contrast-enhanced magnetic resonance angiography accuracy (94.3%); sensitivity (66.7%); and specificity (95.2%) and cine-CMR accuracy (91.6%); sensitivity (66.7%); and specificity (92.5%).

The authors concluded that patients who were candidates for pulmonary vein isolation surgery, cardiac MRI with long inversion time delayed enhancement independently picked up LA and LAA clots in the same 3.5% of patients as did gold-standard TEE, thus CMR could be the single diagnostic study for assessment of pulmonary venous anatomy as well as presence of atrial thrombi thus reducing the number of pre-operative tests before PVI.