Aims: Intracoronary near-infrared spectroscopy (NIRS) in ST-segment elevation myocardial infarction (STEMI) has demonstrated substantial lipid in STEMI culprit plaques. Thrombus aspiration during primary PCI reduces distal embolization and improves reperfusion. This study was performed to examine if aspiration thrombectomy reduces the lipid content of acute coronary syndrome (ACS) culprit plaques.
Methods and results: NIRS-IVUS imaging was performed in patients with an ACS at two hospitals in the US and Sweden. After establishment of TIMI 3 flow with an undersized balloon, NIRS was performed, followed by aspiration thrombectomy, followed by repeated NIRS. The same culprit segment was identified on the post-aspiration chemogram. The culprit lipid content was quantified before and after thrombectomy as the lipid core burden index (LCBI). Aspirates were examined by histological staining for lipids, calcium, and macrophages. In 18 ACS patients (age 65 ± 11, 61% male), culprit lesions were characterized by high lipid content prior to aspiration thrombectomy. Thrombectomy resulted in a 28% reduction in culprit lesion lipid content (pre-aspiration LCBI 466 ± 141 vs. post-aspiration 335 ± 117, P = 0.0001). In addition to thrombus, histological analysis of aspirates demonstrated the presence of lipids, calcium, and macrophages, indicating that fragments of atherosclerotic plaques had been aspirated.
Conclusion: Thrombectomy aspirates both thrombus and lipid-rich fragments of the culprit atherosclerotic plaques, thereby reducing material that may embolize during stenting. Reduction of lipid content before stenting might contribute to the beneficial effects of thrombectomy and may be particularly useful if a large lipid core is present at the culprit site.
Keywords: Lipid-core plaque; Near-infrared spectroscopy; Thrombectomy.
Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: [email protected].