Conservative treatment of anterior ST-segment elevation myocardial infarction with a large thrombus burden in the left main coronary artery

We present a case of a 45-year-old man, who was admitted due to anterior wall ST-segment elevation myocardial infarction of 3 h duration. Coronary angiography showed a normal RCA, thrombotic occlusion of the distal circumflex artery (Cx) and a massive thrombus in the distal left main artery (LM) protruding to the proximal left anterior descending artery (LAD) with preserved distal flow (Figure 1 A). Cautious, but unsuccessful thrombus aspiration (Hunter 6F) was performed. As the patient was stable he was qualified for further conservative treatment with administration of 72-hour infusion of eptifibatide, enoxaparin, acetylsalicylic acid and prasugrel. Echocardiography revealed extensive regional contractility abnormalities of the left ventricle with reduced ejection fraction (38%). Laboratory results showed a maximal troponin I (TnI) level of 83 355 pg/ml.
After 4 days repeated coronary angiography showed only slight reduction of the thrombus. Based on this result the patient was discussed by the local Heart Team and qualified for pharmacotherapy continuation and another coronary angiography again in a few days. Eleven days after admission, the second follow-up was performed, in which no LM thrombus was visible (Figure 1 B). OCT showed presence of a non-flow limiting fibrotic plaque (< 30% stenosis) in the LM and LAD with wall-mounted red thrombus and small elements of white thrombus (Figure 1 C). We did not observe plaque rupture, dissections or any other features of plaque instability. Taking the result into consideration the patient was qualified for conservative treatment without stent implantation.
At the follow-up 3 months after hospitalization the patient reported only mild dyspnea during physical activity without recurrence of chest pain or other major verse cardiovascular events (MACE). Follow-up echocardiography showed a non-enlarged left ventricle with slightly reduced ejection fraction (44%).
Angiographic evidence of thrombus can be seen in 91.6% of patients who present with ST-elevation myocardial infarction (STEMI) [1]. The use of OCT is essential to reveal the underlying pathophysiology, and optimize therapeutic options [2]. Massive intracoronary thrombus has been reported in 16.4% of patients with acute coronary syndrome [3]. The recommended treatment for patients presenting with STEMI is timely primary percutaneous coronary intervention (PCI), including stent implantation, but in some patients the coronary flow may...


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