Background and objective The use of routine aspiration thrombectomy in primary percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI) remains unclear. The purpose of this study was to evaluate the impact of aspiration thrombectomy on myocardial perfusion as assessed index of microcirculatory resistance (IMR).
Methods The study population were 30 patients with STEMI within 6 hr of symptoms onset, who was successfully treated with primary PCI. All participants had TIMI flow 0/1 or definite angiographic thrombus (Grade 3/4). IMR was measured with a pressure sensor/thermistor-tipped guidewire following PCI. ST-segment resolution and myocardial blush grade were also recorded.
Results Mean IMR was somewhat lower in the aspiration thrombectomy group (n = 20) than that of those without aspiration thrombectomy (n = 10, 21.7짹9.2 U vs. 65.8짹5.9 U, P=0.08). Myocardial blush grade >or=2 and ST-segment resolution occurred more frequently in the aspiration thrombectomy group (94.4% vs. 42.9%, p=0.014; and 77.7% vs. 54.6%, P=0.007) The IMR had significant negative correlation with myocardial blush grade (R = -0.67, P=0.02)
Conclusion Aspiration thrombectomy as adjunctive therapy in the treatment of STEMI appears to improve myocardial perfusion in case that the lesion is totally occluded or angiographic thrombus is present. On-site measurement of IMR following primary PCI may be an objective method to assess the adequacy of myocardial perfusion.