The randomized physiologic assessment of thrombus aspiration in patients with acute ST-segment elevation myocardial infarction trial (PATA STEMI): study rationale and design.

INTRODUCTION: Routine thrombus aspiration is proposed to be superior to conventional primary percutaneous coronary intervention (PCI) in terms of improved myocardial perfusion, in patients with ST-segment elevation acute myocardial infarction (STEMI). However, myocardial perfusion after thrombus aspiration has not been evaluated by a quantitative, invasive method. We intend to determine whether manual thrombus aspiration in the infarct-related coronary artery increases myocardial perfusion assessed by index of microcirculatory resistance (IMR) compared with conventional primary PCI. STUDY DESIGN: PATA STEMI is a single-center, prospective, randomized trial with a planned inclusion of 128 patients with the first STEMI. Prior to coronary angiography, patients are randomly assigned to thrombus aspiration using the Eliminate aspiration catheter (Terumo Medical Supply, Japan) or to conventional primary PCI. After completion of primary PCI, IMR is determined both in infarct-related artery and in noninfarct-related arteries without critical stenoses. The primary end-point is a group mean value of IMR after thrombus aspiration compared with conventional primary PCI. Secondary end-points are myocardial perfusion grade, resolution of ST-segment elevation, enzymatic estimation of infarct size, left ventricular remodeling assessed by echocardiographic indices, and major adverse cardiac events rate at 1, 6, and 12 months. CONCLUSION: If manual thrombus aspiration significantly reduces microcirculatory resistance, thereby improving myocardial perfusion, it may become the routine strategy in primary PCI.