Rheolityc thrombectomy in acute myocardial infarction: Effect on microvascular obstruction, infarct size, and left ventricular remodeling

Abstract

We sought to analyze whether rheolytic thrombectomy (RT) in comparison with manual thrombus aspiration (MTA) may reduce microvascular obstruction (MVO), infarct size (IS), and left ventricular (LV) remodeling in ST-elevation myocardial infarction (STEMI). Conflicting results have been reported as to whether MTA reduces MVO and IS. Eighty STEMI reperfused by primary angioplasty and abciximab were randomly allocated (1:1) to RT or MTA. Cardiac magnetic resonance imaging (MRI) was performed in 37 patients (19 RT) and after 1 year in 19 (9 RT); baseline, 1- and 6-month 2D-echo was performed in all patients. MVO and IS were measured 8 min after gadolinium injection with late enhancement sequences and were analyzed quantitatively at a core laboratory blinded to randomization. At baseline TIMI thrombus grade were similar (RT: 4.47 ± 0.84 vs. MTA: 4.67 ± 0.76, P = 0.453). After thrombectomy, thrombus grade decreased to 1.11 ± 1.04 in RT vs. 2.17 ± 1.29 in MTA arm (P = 0.009). RT compared with MTA did not reduced significantly myocardial IS [12.2% (6.4-22.1) vs. 19.0% (7-28.5), P = 0.224] as well as the extent of MVO [0.0% (0.0-0.17) vs. 0.6% (0.0-1.4), P = 0.117], but a trend toward a lower incidence of MVO (16% vs. 44%, P = 0.056) and a less LV remodeling rate were found in RT arm (11% vs. 24%, P < 0.140). RT in comparison with MTA was more effective in thrombus removal, but it did not reduced significantly the IS and the extent of MVO. However, a trend toward a lower incidence of MVO and a better preservation of LV volumes were found in RT arm. © 2015 Wiley Periodicals, Inc.