Prognostic significance of fragmented QRS in patients with ST-elevation myocardial infarction undergoing revascularization

BACKGROUND & OBJECTIVES: This longitudinal study was carried out to evaluate the prognostic significance of fragmented QRS (fQRS) in patients with acute ST elevation myocardial infarction (STEMI) undergoing revascularization. METHODS: This study included 103 STEMI patients belonging to Killip class I and II who underwent primary revascularization. All patients underwent twelve lead ECG at admission before PCI. Serial ECG were done after PCI at 3 hours, 6 hours, 24 hours, 48 hours and at discharge for detection of fQRS and echocardiography on day 3 post revascularization. Patients developing fQRS within 48 hours and with persistence of fQRS till discharge were included in “persistent fQRS” group. They were followed up after 30 days for major adverse cardiac events (MACE) and assessment of LV function by echocardiography. RESULTS: fQRS was present in 64 patients (61.5%) of study population with 37 patients (57.8%) having persistent fQRS. MACE rates were low (4.8%) and did not differ with respect to fQRS. fQRS significantly correlated with LV dysfunction at 30 days on univariate analysis (p-0.003) but not on multivariate analysis (p -0.10). fQRS was significantly related to impaired myocardial reperfusion as assessed by ΣSTR (percent of total ST segment resolution) (adjusted odds ratio, 95% CI [4.265 (1.034 – 17.58)], p = 0.04). CONCLUSION: In our study, fQRS did not predict MACE and LV dysfunction in acute STEMI patients belonging to Killip class I and II on short term follow-up of 30 days. But, fQRS independently predicted impaired microvascular myocardial reperfusion as assessed by ΣSTR.