The prognostic value of fragmented QRS complex of ECG in predicting re-occurrence of cardiac events after emergency percutaneous coronary intervention in patients with acute myocardial infarction

Abstract

Objective To investigate the value of fragmented QRS complexes (fQRS) in predicting 1 year major adverse cardiac events (MACE) incidence after emergency percutaneous coronary intervention (PCI) for acute ST elevation myocardial infarction (STEMI).Methods Ninety-two acute myocardial infarction (AMI) patients treated with direct PCI were included and divided into fQRS group and non-fQRS group according to the presentations of 12-lead ECG recorded in 72 hours after PCI.The myocardial injury markers and MACE incidence were compared between the two groups during hospitalization.All patients were followed up for 1 year for the incidence of MACE.Results On the serial 12-lead ECG recorded for monitoring acute myocardial infarction patients during the in-hospital stay 72h after PCI,44/92 (47.8％) patients were included in non-fQRS group and 48/92 (52.2％) in fQRS group.Compared with non-fQRS group,the ischemic time before PCI was longer with increase in white blood cells count (WBC) after PCI in fQRS group (P =0.016 and P =0.026).Compared with non-fQRS group,the median of peak values of cTNI,CK-MB,and LVEF were respectively higher in fQRS group (P =0.035,0.003,0.048).The incidence of MACE during hospitalization was remarkably high but not significantly different between two groups (P =0.053).The peak values of cTNI,CK-MB were significantly higher in patients with fQRS presenting in both anterior and inferior wall than those in patients with fQRS presenting in anterior wall or inferior wall alone,while lower LVEF and higher MACE occurred in fQRS group without statistical difference from those in non-fQRS group.During a follow-up of mean one year,there were 19 MACE occurred in all patients.The incidence of 1 year MACE in fQRS group was significantly higher than that in non-fQRS group (31.3％ vs.9.1％,P =0.018).Survival analysis showed that event-free survival in fQRS group was significantly lower than that in non-fQRS group (P =0.004).COX model indicated that fQRS was an independent risk factor for re-occurreance of cardiac events in AMI patients after emergency PCI (HR:2.19,95％ CI:1.38-3.50,P =0.023).ROC curve was used for comparing the sensitivity and specialty between fQRS group and ST segment return from the elevated group in predicting MACE of which the area under curve (AUC) was 0.71 and 0.62,respectively without significant difference (Z =1.22,P =0.225).Conclusions fQRS can be used as an independent risk factor for predicting re-occurreance of cardiac events in AMI patients after emergency PCI. Key words: Acute myocardial infarction; Percutaneous coronary intervention; Fragmented QRS; Prognosis