Thrombus aspiration during primary percutaneous coronary intervention for preserving the index of microcirculatory resistance: a randomised study

AIMS: We aimed to investigate whether thrombus aspiration could preserve the index of microcirculatory resistance (IMR) after primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: Sixty-three patients with STEMI were randomised into two groups: primary PCI after thrombus aspiration (aspiration group, n=33) and primary PCI without thrombus aspiration (non-aspiration group, n=30). IMR was measured using a pressure-temperature sensor-tipped coronary wire. Echocardiography was performed at baseline and at six-month follow-up. No significant differences in baseline ejection fraction (EF, 47.3±8.5% vs. 49.5±7.8%, p=0.281) and baseline wall motion score index (WMSI, 1.45±0.31 vs. 1.37±0.27, p=0.299) were observed between the two groups. However, significant differences in IMR (23.5±10.2 U vs. 34.2±21.7 U, p=0.018), %E2%88%86EF (follow-up EF - baseline EF; 3.33±4.6% vs. 0.73±1.9%, p=0.005), and %E2%88%86WMSI (follow-up WMSI - baseline WMSI; -0.121±0.16 vs. -0.004±0.07, p=0.001) were observed between the two groups. CONCLUSIONS: Thrombus aspiration as an adjunctive method to primary PCI for STEMI may preserve microvascular integrity and have beneficial effects on myocardial microcirculation.