Introduction:
The generalization of reperfusion techniques to treat acute myocardial infarction (MI) has allowed for markedly reduced incidence in left ventricular (LV) thrombi because of the reduced myocardial damage. LV thrombi are estimated to complicate 5% to 10% of unselected anterior-wall MI (Ant-MI). However, the incidence and evolution of LV thrombi in high-risk patients with Ant-MI complicated by LV systolic dysfunction is not well known. Cardiac magnetic resonance imaging with contrast delayed enhancement (CMR-DE) is the gold standard in assessing LV thrombus, but comparisons of transthoracic echocardiography (TTE) and CMR-DE are scarce.
Hypothesis:
We assessed whether LV thrombi are still frequent after major Ant-MI, despite systematic dual antiplatelet therapy, and whether focused TTE has a good accuracy for detection as compared with CMR-DE.
Methods:
From 2011 to 2013, from 7 centers, we prospectively included patients with LV ejection fraction (LVEF) < 45% at a first TTE performed < 7 days after Ant-MI. A second evaluation including TTE and CMR-DE (analyzed by blinded examiners) was performed at 30 days. A third TTE and assessment of clinical status and adverse events were performed between months 6 and 12.
Results:
We included 100 consecutive patients (71% males; mean age 59.1 ± 12.1 years; LVEF 33.5 ± 6.0%) at a mean of 4.8 ± 1.9 days after Ant-MI; 88% had undergone primary coronary angioplasty. In total, 26 patients had LV thrombi detected at a mean of 23.2 ± 34.8 days after MI (6 during the first week after the MI, 16 from days 8 to 30, 4 after day 30). As compared with CMR-DE, TTE sensitivity and specificity were 94.7% and 98.5%, respectively. For 24 patients (92.3%), the LV thrombi disappeared with triple antithrombotic therapy including dual antiplatelet therapy and a vitamin K antagonist. One patient died from a recurrent subdural haematoma and another had a peripheral embolism.
Conclusions:
In this prospective multicenter study, LV thrombus occurred in 26% of patients after Ant-MI complicated by LV dysfunction. Focused TTE has a high accuracy for detection. CMR-DE should be performed only when the apex is not clearly seen.
Structural assessment of myocardial infarction scars and left ventricular function with cardiac magnetic resonance imaging in patients at high risk of sudden cardiac death
