Impact of thrombus burden on outcomes after standard versus mesh-covered stents in acute myocardial infarction (from the MGuard for acute ST elevation reperfusion trial).

Large thrombus burden negatively affects the results of percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI). We investigated the impact of thrombus burden in patients with STEMI undergoing primary PCI with the mesh-covered MGuard stent (InspireMD Ltd., Tel Aviv, Israel) versus a control bare-metal or drug-eluting stent. In 433 patients with STEMI randomized to the MGuard stent versus a control stent, angiographically visible thrombus was identified in 383 patients (88.5%), with median thrombus area 30.15 mm(2) (22.70, 41.93). Lesions with large thrombus (area > median) were treated with more frequent use of manual aspiration (80.8% vs 65.8%, p = 0.0009) and longer (22.1 ± 5.9 vs 19.4 ± 5.4 mm, p <0.0001) and larger (3.46 ± 0.40 vs 3.29 ± 0.36 mm, p <0.0001) stents. PCI of lesions with large thrombus burden had more thrombotic complications (30.6% vs 15.9%, p = 0.0007) and reduced angiographic success (80.3% vs 91.1%, p = 0.003). In large thrombus lesions, the MGuard stent was more effective than control stents in achieving Thrombolysis In Myocardial Infarction-3 flow (87.9% vs 74.5%, p = 0.02) and tended to result in less slow flow or no reflow (8.8% vs 17.6%, p = 0.07). ST-segment resolution was improved with the MGuard, and clinical outcomes were favorable in both stent groups, regardless of thrombus burden. In conclusion, reperfusion success is reduced after primary PCI in lesions with large thrombus burden, an outcome that may be modified by the MGuard stent.