[Simple mechanical reperfusion in acute myocardial infarction: determinants, prognostic implications and relation...

Simple mechanical reperfusion (SMR) is defined as reperfusion achieved after wire insertion at the occluded infarct-related artery in primary angioplasty. The determinants and prognostic implications of SMR and its relationship with the histopathology of the rescued thrombus were evaluated in 601 patients with acute myocardial infarction showing ST elevation and pre-procedural total occlusion of the infarct-related artery (TIMI flow 0). Two groups were considered according to the presence of SMR, defined as the visualization of contrast material after crossing the occlusion with the guide wire. SMR was achieved in 303 patients (50.4%) and was found to be associated with less time to treatment (248 vs. 286 minutes; p = 0.001), less deteriorated initial left ventricular function and shock at admission (9.2 vs. 16.4%; p = 0.008), higher successful rate (94.7% vs. 78.5%; p < 0,0001) and of higher rate of thrombus rescue: 70/81 vs. 27/79 patients (p < 0.0001). The right coronary artery was the most frequent infarct-related artery. Histopathology of the retrieved thrombi was available for 160 patients treated with thrombus aspiration. SMR was associated with smaller thrombus, lower contents of leukocytes and erythrocytes, and higher thrombus content of inflammatory cells, cholesterol and collagen crystals from the atheromatous plaque. SMR is an independent predictor of procedure success and its relationship with the anatomy of the thrombus could redefine the indication of thrombus aspiration.