Non‐ST‐elevated myocardial infarction with “N” wave on electrocardiogram and culprit vessel in left circumflex has a risk equivalent to ST‐elevated myocardial infarction

BACKGROUND: It was found that delayed activation wave often appeared in terminal QRS wave in non‐ST‐elevated myocardial infarction (NSTEMI) with culprit vessel in left circumflex artery (LCX), yet little is known about the similarities among non‐“N”‐wave non‐ST‐elevated myocardial infarction (N‐NSTEMI) and ST‐elevated myocardial infarction (STEMI). HYPOTHESIS: In AMI patients with the culprit vessel in LCX, “N” wave NSTEMI has a risk equivalent to STEMI. METHODS: All 874 patients admitted to Shenjing Hospital of China Medical University between January 1, 2013 and December 30, 2017 were included and whose coronary angiography (CAG) indicated the culprit vessel in LCX. Patients were divided into three groups: ST‐elevated myocardial infarction group (STEMI group, n = 322), “N” wave non‐ST‐elevated myocardial infarction group (N‐NSTEMI group, n = 232) and non‐“N”‐wave NSTEMI group (non N‐NSTEMI group, n = 320). The basic data and the incidence of MACE during hospitalization and 12 months were analyzed. RESULTS: In STEMI and N‐NSTEMI groups, AST, CK, CK‐MB, TnI, and stenosis severity were significantly higher than non N‐NSTEMI (P < .05). The lesions in the N‐NSTEMI and STEMI groups were more often located proximal LCX before giving rise to OM1 of LCX (P < .05), however, the non N‐NSTEMI group was often located distal LCX after giving rise to OM1 and the OM1 (P < .05). The incidence rates of all MACEs, all‐cause death, ST, TVR, and rUAP were similar in N‐NSTEMI and STEMI groups, which were greater than non N‐NSTEMI (P < .05). Both N‐NSTEMI and STEMI are independent risk factors for MACE (P < .05). CONCLUSION: The basic data and the incidence of major adverse cardiac event were similar in N‐NSTEMI and STEMI patients, N‐NSTEMI has a risk equivalent to acute STEMI.