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.