Abstract: ［Abstract］ Objective〖HTSS〗〓To observe the treatment effects of the targeted coronary intravascular injection of nicorandil combined with tirofiban on noreflow phenomenon(NRP) during primary percutaneous coronary intervention(PPCI)in  patients with acute STelevation myocardial infarction(STEMI).
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓One hundred and twenty patients with acute STEMI were randomly divided into tirofiban group(T group), nicorandil group(N group) and combined medication group(T+N group), each group had 40 cases. When the NRP occurred,T group, N group and T+N group were injected with tirofiban(25 μg/kg), nicorandil(4 mg) and tirofiban(25 μg/kg) plus nicorandil(4 mg) respectively by the micro catheter coronary target vessels. After the operation, 3 groups were injected intravenously tirofiban（0.15 μg·kg-1·min-1）, nicorandil(8 mg/h), tirofiban（0.15 μg·kg-1·min-1）plus nicorandil(8 mg/h) for 24 h, respectively. The thrombolysis in myocardial infarction(TIMI) blood flow grade of infarction related artery, corrected TIMI frame count(cTFC), TIMI myocardial perfusion grade(TMPG) before and at the end of PPCI operations, the STsegment resolution(STR) rate 90 min after operations, creatine kinase isoenzymeMB(CKMB) and cardiac troponinI(cTnI) before operations and those peak volume after operations, nterminal probrain natriuretic peptide(NTproBNP), wall motion score index(WMSI), left ventricular ejection fraction(LVEF), the incidence of intraoperative malignant arrhythmia, hypotension, bleeding and major adverse cardiac events(MACEs) after operations were observed and recorded.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓Compared with N group and T group, the cTFC frames and the peak volume of CKMB and cTnI after PPCI, and NTproBNP and WMSI 1 week after operations in T+N group were significantly decreased(P＜0.05), but the proportion of TIMI 3 grade and TMPG 3 grade after operations, the STR rate 90 min after operations and the LVEF 1 week after operations in T+N group were significantly higher(P＜0.05). There was no significant difference in the above indice between N group and T group(P＞0.05). The incidence of malignant arrhythmia rate in N group or T+N group was lower than that in T group(P＜0.05).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓Target coronary intravascular injection of nicorandil combined with tirofiban after NRP occurred can safely and effectively treat the occurrence of NRP during PPCI operation in acute STEMI patients, and improve the level of myocardial perfusion and heart function.

Key words: myocardial infarction, noreflow phenomenon, percutaneous coronary intervention