Canadian Journal of Cardiology

Physicians' Attitudes Towards Anticoagulation for Prevention and Treatment of Left Ventricular Thrombus Following Anterior Myocardial Infarction

      To the Editor:
      The recently published “2018 Canadian Cardiovascular Society (CCS) Focused Update of the Guidelines for the Use of Antiplatelet Therapy” by Mehta et al.
      • Mehta S.R.
      • Bainey K.R.
      • Cantor W.J.
      • et al.
      2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology focused update of the guidelines for the use of antiplatelet therapy.
      made recommendations regarding prophylaxis and treatment of left ventricular (LV) thrombus in the setting of percutaneous coronary interventions (PCI). At present, there are no randomized controlled trials providing evidence for optimal practice in this population.
      To investigate current Canadian practice, we conducted a cross-sectional survey of cardiologists and their practices toward treatment and prophylaxis of LV thrombus following anterior ST-elevation myocardial infarction (STEMI). The web-based survey was distributed using SurveyMonkey (SurveyMonkey, San Mateo, CA) between November 2017 and January 2018 and consisted of 16 multiple-choice questions. It included 3 clinical scenarios of patients following anterior STEMI with no LV thrombus, possible LV thrombus, and definite LV thrombus on echocardiography (Supplementary Material).
      A total of 42 responses were collected. The majority of responses (81%) were from Ontario cardiologists, and 88% worked in academic settings. In patients with anterior STEMI without clear LV thrombus and left ventricular ejection fraction (LVEF) ≤ 40%, our survey showed that dual-antiplatelet therapy (DAPT) alone was considered an appropriate treatment by 79% of surveyed cardiologists, whereas 29% also considered treatment with triple therapy using aspirin (ASA), clopidogrel, and warfarin appropriate (Fig. 1A). The majority of respondents described an approach consistent with the recent CCS guideline, which recommended treatment with DAPT using ASA in addition to ticagrelor or prasugrel without warfarin. This recommendation is based on retrospective studies demonstrating increased risk of bleeding due to warfarin with no net reduction in ischemic events in this patient population.
      • LeMay M.R.
      • Acharya S.
      • Wells G.A.
      • et al.
      Prophylactic warfarin therapy after primary percutaneous coronary intervention for anterior ST-segment elevation myocardial infarction.
      • Maniwa N.
      • Fujino M.
      • Nakai M.
      • et al.
      Anticoagulation combined with antiplatelet therapy in patients with left ventricular thrombus after first acute myocardial infarction.
      Figure thumbnail gr1
      Figure 1Medical regimens considered to be reasonable practice at discharge for patients following anterior ST-elevation myocardial infarction (STEMI) with normal renal function, left ventricular ejection fraction (LVEF) ≤40%, and either (A) no LV thrombus, (B) possible layered LV thrombus, or (C) definite LV thrombus on echocardiogram.
      For treatment of patients with established LV thrombus undergoing PCI, the CCS guideline suggests initial therapy with ASA, clopidogrel, and oral anticoagulant but discontinuing the ASA as early as the first day following PCI or up to 6 months post-PCI. However, the guideline does note the very low quality of evidence supporting this recommendation, especially the use of direct oral anticoagulants (DOACs) in patients with LV thrombus. At present, 69% of surveyed cardiologists consider treatment with ASA, clopidogrel, and warfarin reasonable practice on discharge for patients with established LV thrombus after undergoing PCI. However, approximately 30% support use of other treatment options including the following combinations: ASA, clopidogrel, and DOAC; clopidogrel and warfarin; or clopidogrel and DOAC (Fig. 1, B and C).
      Our survey demonstrates the variability in practice patterns in prophylaxis and treatment of LV thrombus following anterior STEMI and PCI. With the low incidence of events, large randomized trials are difficult to conduct, but more studies are needed to establish optimal treatment strategy in these patient populations.

      Disclosures

      The authors have no conflicts of interest to disclose.

      Supplementary Material

      References

        • Mehta S.R.
        • Bainey K.R.
        • Cantor W.J.
        • et al.
        2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology focused update of the guidelines for the use of antiplatelet therapy.
        Can J Cardiol. 2018; 34: 214-233
        • LeMay M.R.
        • Acharya S.
        • Wells G.A.
        • et al.
        Prophylactic warfarin therapy after primary percutaneous coronary intervention for anterior ST-segment elevation myocardial infarction.
        JACC Cardiovasc Interv. 2015; 8: 155-162
        • Maniwa N.
        • Fujino M.
        • Nakai M.
        • et al.
        Anticoagulation combined with antiplatelet therapy in patients with left ventricular thrombus after first acute myocardial infarction.
        Eur Heart J. 2018; 39: 201-208