The impact of the excimer laser on myocardial salvage in ST-elevation acute myocardial infarction via nuclear scintigraphy.

Data on the efficacy of excimer laser coronary atherectomy (ELCA) for patients with ST-elevation myocardial infarction (STEMI) are limited. Therefore, we sought to evaluate the impact of ELCA on myocardial salvage using nuclear scintigraphy in patients with STEMI. Between September 2014 and April 2017, we retrospectively enrolled 316 consecutive patients undergoing primary PCI (p-PCI) after their first STEMI in our institute. Of those, 72 patients with STEMI, an initial thrombolysis in myocardial infarction (TIMI) flow-0/1, and an onset to balloon time (OBT) < 6 h were included (ELCA, n = 32; non-ELCA, n = 40). The endpoint was the myocardial salvage index (MSI) based on a 17-segment model with a 5-point scoring system. MSI was calculated as: MSI = (∑123I-BMIPP defect score at 3-7 days after p-PCI - ∑99mTc-tetrofosmin defect score at 3-6 months after p-PCI)/∑123I-BMIPP defect score × 100 (%) at 3-7 days after p-PCI. The groups were compatible except in age (ELCA: 62.9 ± 12.4 years vs. non-ELCA: 69.8 ± 11.0 years) and loading antiplatelet drug (prasugrel: 100% vs. 40.0%). Direct implantation of shorter stents more frequently occurred in the ELCA group than in the non-ELCA group. MSI seemed to be better in the ELCA group compared with the non-ELCA group (57.6% vs. 45.6%, p = 0.09). This trend was emphasized when the final TIMI-3 flow was achieved (67.1% vs. 45.7%, p = 0.01). The nuclear scintigraphy results showed that ELCA can potentially improve myocardial salvage in patients with STEMI with OBT < 6 h and initial TIMI flow-0/1.