OBJECTIVESTo investigate whether the administration of recombinant human B-type natriuretic peptide (rhBNP) before primary percutaneous coronary intervention (PCI) could further limit the infract size, improve left ventricular function, and alleviate cardiac dilation in patients with acute ST-segment elevation myocardial infarction(STEMI).

METHODSA total of 93 consecutive patients presenting chest pain within 12 hours from the onset, suspicious of first STEMI located at anterior wall undergoing primary PCI, were eligible for enrollment and randomly assigned to either rhBNP group (rhBNP administration starting at 5 min before PCI, 1.5 µg/kg bolus intravenous injection followed by 0.007 5-0.03 µg·kg(-1)·min(-1) for up to 120 hours, n=48) or nitroglycerin (NIT) group (NIT treatment starting at 5 min before PCI, 10-100 µg/min intravenous infusion for 120 hours, n=45). Primary PCI was performed in both groups using post-conditioning (PC) technique. TIMI flow grade, corrected TIMI frame count, and TIMI myocardial perfusion grade were compared between the two groups at the time of infarct related artery (IRA) re-patency. The levels of serum creatine kinase MB isoenzyme (CK-MB) and troponin I (TnI) were measured. Echocardiography was performed at baseline 7 days and 6 months later.

RESULTSBaseline characteristics were similar between the two groups. The percentage of TIMI grade 3 and TIMI myocardial perfusion grade 3 after PCI both tended to be higher in rhBNP group than those in NIT group (95.8%(46/48) vs. 86.7%(39/45), P=0.162) and (72.9%(35/48) vs. 62.2%(28/45), P=0.500). The corrected TIMI frame count was significantly decreased in rhBNP group (21.0±8.7 vs. 28.2±14.8, P=0.005). The myocardial infarct size expressed as the AUC of CK-MB ((3 249±1 101) U/L vs. (4 474±1 661)U/L, P=0.010) or AUC of TnI ((3 670±942) µg/L vs. (4 541±1 098) µg/L, P=0.021) was significantly decreased in rhBNP group compared with those in NIT group. At 7 days after primary PCI, the left ventricular ejection fraction (LVEF) tended to be higher (P>0.05), while the E/e' index and wall motion score index (WMSI) ((11.95±3.31 vs. 14.60±4.09, P=0.030) and (1.74±0.17 vs. 2.40±0.55, P<0.001)) were significantly improved in rhBNP group compared with those in NIT group. BNP level was also significantly lower in rhBNP group compared that in NIT group ((68.3±37.8) ng/L vs. (129.4±64.4) ng/L, P<0.001). During 6-month follow-up, LVEF and WMSI were significantly improved in rhBNP group compared those in NIT group(51.7%±12.7% vs. 46.9%±9.6%, P=0.024 and 1.69±0.35 vs. 1.92±0.47, P=0.020).

CONCLUSIONAdministration of rhBNP before PCI with post-conditioning procedure can further improve myocardial perfusion, limit myocardial infarct size, ameliorate cardiac dysfunction and postpone left ventricular early-stage and long-term remodeling in STEMI patients undergoing primary PCI.