The value of fragmented QRS in predicting angiographic reperfusion and electrocardiographic ST resolution in patient with ST Elevation myocardial Infarction (STEMI) undergoing Primary percutaneous coronary intervention (PPCI)

Abstract

Various studies have shown that FQRS usually appears on the electrocardiogram 24 to 48 hours after the onset of symptoms, which is associated with a poor prognosis. In the present study, we aimed to study the association between pre and post angioplasty FQRS and TIMI flow and ST-segment resolution in patients with STEMI Methods: In this cross-sectional study, 504 patients with STEMI who were referred to Shahid Madani Hospital were included. Then, based on the pre-designed checklist, the initial demographic and clinical information of the patients were recorded from the patients' files. These information was also recorded after angioplasty. Patients were followed up for 24 hours to 48 hours after the onset of FQRS and were divided into two groups of patients with FQRS and patients without FQRS and were followed up. During hospitalization occurrence of recurrent MI and heart failure were recorded. In this study, if the initial TIMI score (before angioplasty) was 2 and 3, it was considered as spontaneous reperfusion and also reperfusion after angioplasty was considered based on TIMI score of 3. In the case of ST-segment return, if the ST-segment return was more than 70% to the isoelectric line 90 minutes after injection, it was considered as a complete ST-segment return. SPSS V.21 software was used for statistical analysis. Independent t-test was used to compare quantitative variables between the two groups if the data distribution was normal and Mann-Whitney U method was used if the data distribution was abnormal. Chi-Square test was used to compare qualitative variables between the two groups. To determine the relationship, logistic regression test with adjustment on confounders was used. Value less than 0.05 was considered significant. Results: In this study, 504 patients with STEMI participated with a mean age of 57.64±11.02 years. 82.9% of participants were male and 2.8% of patients before angioplasty 29 % of patients after angioplasty had FQRS. 0.19% of patients had recurrent myocardial infarction after angioplasty (1 patient out of 504 patients) and 10.91% of patients also had heart failure. 44.1% of patients had complete return of ST segment after angioplasty. There was no significant relationship between FQRS before angioplasty and TIMI score of 2, and 3. In 87.5% of patients with complete ST-segment return after angioplasty, complete blood flow was established after angioplasty, which was 77% in patients without complete ST-segment return. The difference between the two groups was statistically significant (p = 0.04). The presence of FQRS before and after angioplasty was a significant predictor of non-return of ST segment (p <0.05). With increasing TIMI score after angioplasty, the probability of ST-segment return increased significantly. TIMI scores of 2 and 3 before angioplasty were significantly the protective factor against FQRS after angioplasty. (p = 0.008)