Case Summary: A 30-year-old male patient was admitted to our emergency department with typical chest pain (CCS IV). Vital signs showed a heart rate of 87bpm, tachypnoea of 27/min and a blood pressure of 140/110mmHg. Cardiovascular risk factors consisted of nicotine consume, hypertension and obesity. The electrocardiogram showed no ST-segment elevation. Laboratory results came back with a creatinine kinase of 310U/l (cutoff <190U/l), a creatinine kinase-MB of 51U/l (cutoff < 24U/l and <6% of CK) and an initially elevated troponin of 558pg/ml (cutoff <14pg/ml). Echocardiography revealed a normal left-ventricular ejection fraction with no regional wall motion abnormalities. The TIMI score (NSTEMI) was 4 (mortality risk of 19.9%). Known previous illness consisted of a portal vein thrombosis which was treated with oral anticoagulation since 2018. Thrombophilia was ruled out in 2019. In the cardiac catheriztation the right coronary artery showed no signs of obstruction. In the left main (LM) and ostial LAD, a thrombus was found. The medial LAD was obstructed by 99% (Fig. 1). After direct percutaneous coronary intervention of the medial LAD with two drug-eluting stents we used intravascular ultrasound (IVUS) on the medial LAD, ostial LAD and LM. IVUS showed a good stent apposition in the medial segment with a remaining thrombus in the LM (Fig. 2). We wanted to avoid LM stenting and decided to put the patient on therapeutic anticoagulation (TA) and to repeat the catherization exam. After two days of TA with unfractionated heparin, aspirin and prasugrel there was no thrombus left (Fig. 3). The patient was discharged with an oral antiplatelet therapy of aspirin, clopidogrel and phenprocoumon. One month later he presented himself again with atypical pain in the left thorax. Coronary catheterization was done and neither in the angiography nor the IVUS there were any signs of thrombus (Fig. 4). We decided to prolong the triple antiplatelet therapy for another 5 months.
Discussion: Deferred stenting in patients with high thrombus burden has been a subject of investigation over the years. Several studies showed a reduction in infarct size, microvascular obstruction and cardiovascular death. Yet they failed to show consistent results in a standardized approach for deferred stenting. The most accepted criteria in STEMI patients so far are a large thrombus burden, a lesion length greater than 24mm and clinical criteria like young age, male patient and a large vessel diameter. Although additional advantages, like lesser number of stents, can be achieved disadvantages like bleeding and reocclusion need to be considered. In our case TA under close monitoring was sufficient to resolve the thrombus. With no history of bleeding (CRUSADE Score 4) and a good compatibility of triple antiplatelet therapy the decision to prolong the oral medication seems reasonable. Nonetheless, the underlying cause remains unclear since the initial thrombophilia screening showed no pathological findings.
Fig. 1: Initial angiography
Fig. 2: IVUS LM
Fig. 3: Angiography after 48h
Fig. 4: Angiography after 1 month
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