Intracoronary thrombolysis in patients with ST-segment elevation myocardial infarction presenting with massive intraluminal thrombus and failed aspiration.

Aim: Massive intracoronary thrombus is associated with adverse procedural results including failed aspiration and unfavourable reperfusion. In this scenario the best treatment remains unknown. We aim to evaluate the effect of low dose intracoronary thrombolysis in patients with ST-segment elevation myocardial infarction (STEMI) presenting with a large thrombus burden and failed aspiration.

Methods And Results: In this study 30 STEMI patients with a large thrombus burden and failed manual aspiration were included in the registry. Local fibrinolysis with low dose (one-third of systemic) tenecteplase (27%) or alteplase (73%) was administered via a 6F-infusion catheter. A thrombus was qualified as large when its maximal dimension was ≥2 vessels (thrombolysis in myocardial infarction (TIMI) thrombus grade 4 and 5). Altogether 33% of patients received delayed invasive therapy (>12 h) guided by the presence of recurrent symptoms and/or ischaemia. A total of 17% of patients presented with cardiogenic shock and half of the population received glycoprotein IIb/IIIa inhibitors. A post-lysis thrombus grade 4-5 was found in just one patient. TIMI flow grade improved from 0/1 at baseline (93%) to ≥2 in most patients (97%). Blush grade 2-3 was observed in 85% and we observed a similar percentage (82%) of more than 50% ST-segment resolution. In-hospital mortality was 10% (three patients with cardiogenic shock). No major bleeding events were observed. At a median follow-up of 14 (6-35) months, only one new clinical event was reported (1 target lesion revascularization, (TLR)).

Conclusions: In STEMI patients with a large thrombus burden and failed manual aspiration, administration of low dose intracoronary thrombolysis is safe and reduces trhombus burden, as a result improving in epicardial flow and myocardial reperfusion.