Clinical Impact of Perfusion Balloon for ST-segment Elevated Myocardial Infarction: RYUSEI Study

Abstract

Drug-eluting stents have significantly contributed to reducing mortality in patients with ST-segment elevation myocardial infarctions (STEMIs), but slow flow/no-reflow phenomenon (SFNR) and in-stent restenosis are still clinical problems. On the other hand, perfusion balloons (PBs) can compress thrombi and ruptured plaque for long inflation without ischemia and can be used as a delivery device for infusion of nitroprusside to distal risk area during ballooning. We conducted RYUSEI (Reduction of risk bY perfUsion balloon for ST-segment Elevated myocardial Infarction) study to evaluate whether PBs before stenting are more effective than conventional stenting for STEMIs. We divided consecutive patients with STEMIs who underwent optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) into PB group who were treated with PBs (Ryusei®; Kaneka Medix Corporation, Osaka, Japan) before stenting and the conventional PCI (CP) group. We compared clinical results including SFNR, OCT findings, and clinical events between the two groups. We finally analyzed 34 patients in PB group and 90 in CP group. After propensity score matching, PB and CP groups consisted of 23 patients, respectively. In the propensity score-matched cohort, SFNR and maximum protrusion area detected by OCT were significantly lower (P=0.047 and P=0.019) and TIMI flow grade 3 higher (P=0.022) in the PB group than CP group. Kaplan-Meier analysis revealed a significantly better clinical outcome in PB group than CP group (p=0.038). In conclusion, the RYUSEI study revealed a pre-stent lesion modification in addition to nitroprusside infusion using PB is useful to achieve better clinical course in STEMI patients.