A comparison of 2 thrombus aspiration devices with histopathological analysis of retrieved material in patients presenting with ST-segment elevation myocardial infarction.

OBJECTIVES The objective of this study was to compare 2 manual thrombus aspiration catheters in unselected patients with ST-segment elevation myocardial infarction. BACKGROUND Distal embolization is common during percutaneous coronary intervention in ST-segment elevation myocardial infarction and can induce impaired myocardial perfusion. Several aspiration thrombectomy devices have been introduced to prevent distal embolization, however, with conflicting clinical results. Currently, it is unclear to what extent this variance in outcome can be explained by device-related factors, such as internal lumen size. METHODS We performed a prospective cohort study in which patients undergoing primary percutaneous coronary intervention were treated with a large-internal-lumen catheter (Diver, Invatec, Roncadelle, Italy). Outcomes were compared with a matched population of the Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS) trial, in which patients were treated with a medium-sized catheter (Export, Medtronic, Minneapolis, Minnesota). A histopathological analysis was performed of retrieved material. RESULTS A total of 160 patients, treated with the Diver (n = 80) or Export (n = 80) aspiration catheter, were enrolled. Effective thrombus aspiration was seen in 70.3% of the patients treated with the Diver catheter versus 81.8% with the Export catheter (p = 0.10) No significant difference was found in myocardial blush grade or electrocardiographic outcome between the 2 devices. Size distribution of retrieved thrombotic particles was similar per device. Erythrocyte-rich thrombi were found in 34.8% of the cases and were predominately seen in patients with low initial Thrombolysis In Myocardial Infarction flow grade (p = 0.008). CONCLUSIONS A larger internal lumen diameter does not result in retrieval of larger thrombotic particles, nor in improved angiographic or electrocardiographic outcomes.