Prevention of distal embolization and no-reflow in patients with acute myocardial infarction and total occlusion in the infarct-related vessel: A subgroup analysis of the cohort of acute revascularization in myocardial infarction with excimer laser?CARMEL multicenter study

Abstract

To overcome the adverse complications of percutaneous coronary interventions in thrombus laden lesions (i.e., distal embolization, platelet activation, no-reflow phenomenon), mechanical removal of the thrombus or distal embolization protection devices are frequently required. Pulsed-wave ultraviolet excimer laser light at 308 nm can vaporize thrombus, suppress platelet aggregation, and, unlike other thrombectomy devices, ablate the underlying plaque. The following multicenter registry was instituted to evaluate the safety and efficacy of laser ablation in patients presenting with acute myocardial infarction (AMI) complicated by persistent thrombotic occlusions. Patients with AMI and complete thrombotic occlusion of the infarct-related vessel were included in eight participating centers. Patients with further compromising conditions (i.e., cardiogenic shock, thrombolysis failures) were also included. Primary endpoint was procedural respective laser success; secondary combined endpoints were TIMI flow and % stenosis by quantitative coronary analysis and visual assessment at 1-month follow-up. Eighty-four percent of all patients enrolled (n = 56) had a very large thrombus burden (TIMI thrombus scale > or = 3), and 49% were compromised by complex clinical presentation, i.e., cardiogenic shock (21%), degenerated saphenous vein grafts (26%), or thrombolysis failures (5%). Laser success was achieved in 89%, angiographic success in 93%, and the overall procedural success rate was 86%. The angiographic prelaser total occlusion was reduced angiographically to 58% +/- 25% after laser treatment and to 4% +/- 13% final residual stenosis after adjunctive balloon angioplasty and/or stent placement. TIMI flow increased significantly from grade 0 to 2.7 +/- 0.5 following laser ablation (P < 0.001) and 3.0 +/- 0.2 upon completion of the angioplasty procedure (P > 0.001 vs. baseline). Distal embolizations occurred in 4%, no-reflow was observed in 2%, and perforations in 0.6% of cases. Laser-associated major dissections occurred in 4% of cases, and total MACE was 13%. The safety and efficacy of excimer laser for thrombus dissolution in a cohort of high-risk patients presenting with AMI and total thrombotic occlusion in the infarct-related vessel are encouraging and should lead to further investigation.