Echocardiography and clinical management
In patients with recent anterior MI and high-risk non-contrast apical wall motion score (≥5), pre-discharge image enhancement with ultrasound contrast agents is recommended in the absence of contraindications. In those without LVT, one approach may involve a repeated TTE after ≅ 2 weeks (Fig.4). If LVT is not detected on repeated TTE, anticoagulants are not indicated.44 Conversely, in the case of detection of LVT, oral anticoagulants should be immediately started with a parenteral anticoagulant bridging. A combination of warfarin with single P2Y12 inhibitor (double therapy) may be preferred over triple therapy, in light of accumulating evidence suggesting the reduced bleeding risk of this approach from studies on patients with atrial fibrillation associated with acute coronary syndrome.39  Hence, when used in combination with an oral anticoagulant, clopidogrel should be preferred above aspirin and more potent P2Y12 inhibitors. In patients at high risk of recurrent MI or stent thrombosis, a short course (e.g., 1 month) of triple therapy might be considered when balanced against the bleeding risk.
In patients with difficulty to maintain the therapeutic anticoagulation range with warfarin a full-dose DOAC may be preferred.21
The optimal duration of oral anticoagulation in patients with LVT after MI has never been tested in the era of dual antiplatelet therapy. According to current guidelines, anticoagulants should be added to antiplatelet therapy for a variable time of 3-6 months since the duration must be individualized according to bleeding risk.20, 35, 36 At the end of this period, a repeated TTE with ultrasound contrast agents should be performed. If the LVT has resolved, anticoagulants can be dismissed while continuing DAPT. Nevertheless, a prudent approach with an additional TTE with ultrasound contrast after a further 3 months is suggested. In the case of LVT recurrence at any time, long-term anticoagulation must be maintained unless other contraindications. In patients without LVT resolution or persistent apical spontaneous echo-contrast, the optimal therapeutic management is unclear, and decision regarding continuation of oral anticoagulation should be made on a case-by-case basis (Fig.3).
Recently, a real-world post hoc analysis from a single-center study with independently verified LVT (mainly diagnosed by TTE) indicated that thrombus regression, which occurred in 62.3% of cases, represents a strong independent marker of lower morbidity and mortality. Conversely, patients with persistent LVT were at high risk of clinical complications even when combining with antiplatelet agents.11 The observation that in this cohort as many as 1/3 of patients did not achieve total LVT regression and that even 14.5% had recurrent or increased size of LVT emphasize the need for more efficient therapeutic strategies to improve and accelerate LVT regression. Yet, any intensification of the antithrombotic treatment may be compromised by more frequent and more severe bleeding complications. Therefore, an individualized risk stratification based on patient characteristics and LVT evolution under TTE guidance could be the ideal decision-making approach. However, only a prospective, randomized controlled trial may detect and quantify the advantages of anticoagulation intensification versus long-term maintenance of standard anticoagulation in these cases.