Relationship of fragmented QRS with prognostic markers and long-term major adverse cardiac events in patients undergoing coronary artery bypass graft surgery.

Abstract

Fragmented QRS (fQRS) complex is associated with increased sudden cardiac death, recurrent cardiovascular events, morbidity and mortality. However, the prognostic role of fQRS has not been comprehensively studied in patients undergoing coronary artery bypass graft (CABG) surgery. In this study, we planned to investigate the relationship of fQRS with prognostic markers and long-term major adverse cardiovascular events (MACEs) following isolated CABG surgery. Two hundred and thirteen patients who underwent CABG surgery at our institution were enrolled consecutively. MACE was defined as cardiac death, recurrent myocardial infarction, decompensated heart failure and re-hospitalization. The patients were followed up for a mean duration of 26 ± 10 months for MACE. Patients with fQRS had a higher rate of Q wave on ECG (30 vs. 10%, P < 0.001), more prolonged QRS time (99 ± 11 vs. 88 ± 13 ms, P < 0.001), higher EUROSCORE (4.0 ± 1.9 vs. 2.7 ± 1.5, P < 0.001) and lower left ventricular ejection fraction (44 ± 12 vs. 56 ± 12, P < 0.001) in comparison with patients with non-fQRS. In addition, patients with fQRS had increased short-term and long-term MACE (17 vs. 4%, P = 0.002; 23 vs. 6%, P < 0.001, respectively) after discharge. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of fQRS for predicting MACE were 67, 71, 23, 94 and 70%, respectively. fQRS [odds ratio (OR) 3.110, 95% confidence interval (CI) 1.157-8.362, P = 0.025] and prolonged QRS duration (>100 ms) (OR 3.898, 95% CI 1.463-10.39, P = 0.007) were the only independent predictors of long-term MACE in multivariate logistic regression analysis. However, QRS duration had a better association with MACE than the presence of fQRS. fQRS and prolonged QRS duration may have an additional value in predicting cardiac status and long-term prognosis. Fragmentations on admission ECG and prolonged QRS duration may be useful for identifying patients with higher long-term risk who will need more intense treatment and close follow-up after CABG surgery.