NM

A 56-year-old male, with 40-pack-year of smoking and dyslipidemia, presented to a district hospital after 6 hours of sudden chest pain. He was hemodynamically stable. ECG showed sinus rhythm with ST-segment elevation in inferior leads suggestive of inferior STEMI. Since there was no cardiac catherization facility nearby, he was given oral aspirin with clopidogrel and successfully thrombolysed with IV streptokinase. He was then referred to a cardiac centre for early coronary angiogram.

Repeat ECG at the cardiac centre showed sinus rhythm and complete resolution of ST-segment elevation with T-wave inversions in the inferior leads. Echocardiogram showed left ventricular ejection fraction of 50% with inferior and posterior wall hypokinesia. 

Coronary angiogram performed 1 week later after the acute presentation showed total occlusion (TIMI Thrombus grade 5) from proximal RCA (dominant vessel) with high thrombus burden. The left coronaries were normal.
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Thrombus aspiration was attempted with Export Advance catheter and TIMI 2 flow was achieved. In view of persistent high thrombus burden, IV glycoprotein IIb/IIIa inhibitor (Tirofiban) was given for 36 hours with subcutaneous fondaparinux for 5 days. He remained stable without angina. Repeat coronary angiogram showed persistent heavy thrombus burden in the RCA with TIMI 2 flow. Thrombus aspiration was attempted again but failed to achieved satisfactory result for intracoronary imaging or stenting. Mechanical thrombectomy device was not available in our centre. Therefore, it was decided that the patient needed a longer duration of antithrombotic therapy before repeat coronary angioplasty. Patient had a very low bleeding risk score. After a comprehensive discussion, considering the risks and benefits he chose a trial of dual antiplatelet therapy with Rivaroxaban 20mg daily for 1 month. He was not keen for oral vitamin K antagonist or subcutaneous low molecular weight heparin. He returned 1 month later and coronary angiogram showed complete resolution of intracoronary thrombus with moderate lesion in mid RCA. Fraction flow reserve was 0.98 and we decided that stenting was not required. He was discharged with DAPT plus standard guideline-directed medical therapy and remained well during his first year of follow-up.
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This case demonstrated a persistent heavy intracoronary thrombus burden in a patient with recent inferior STEMI despite given IV streptokinase, dual oral antiplatelet therapy, IV glycoprotein IIb/IIIa inhibitor, subcutaneous low molecular weight heparin and multiple attempts of thrombus aspiration. Further intracoronary intervention was delayed to allow for longer duration of antithrombotic therapy with DAPT and direct oral anticoagulant (DOAC) till one month, which resulted in complete resolution of intracoronary thrombus and prevented angioplasty of a vessel without significant stenosis. However, further trials or evidence are needed for management of similar cases.