Predictive value of the fragmented QRS complex in 6-month mortality and morbidity following acute coronary syndrome

Fariborz Akbarzadeh,¹ Leili Pourafkari,¹ Samad Ghaffari,¹ Mohammad Hashemi,² Homayoun Sadeghi-Bazargani<sup>3,4

1</sup>Cardiovascular Research Center of Tabriz University of Medical Sciences, ²Isfahan University of Medical Sciences, ³Traffic Injury Prevention Research Center, Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz, Iran; ⁴PHS Department, Karolinska Institute, Stockholm, Sweden

Background: Fragmented QRS encompasses different RSR' patterns showing various morphologies of the QRS complexes with or without the Q wave on a resting 12-lead electrocardiogram. It has been shown possibly to cause adverse cardiac outcomes in patients with some heart diseases, including coronary artery disease. In view of the need for risk stratification of patients presenting with acute coronary syndrome in the most efficacious and cost-effective way, we conducted this study to clarify the value of developing fragmented QRS in a cohort of patients presenting with their first acute coronary syndrome in predicting 6-month mortality and morbidity.
Methods: One hundred consecutive patients admitted to the coronary care unit at Shahid Madani Heart Center in Tabriz from December 2008 to March 2009 with their first acute coronary syndrome were enrolled in this prospective study. Demographic and electrocardiographic data on admission, inhospital mortality, and need for revascularization were recorded. Electrocardiography performed 2 months after the index event was examined for development of fragmented QRS. Mortality and morbidity was evaluated at 6-month follow-up in all patients.
Results: The patients were of mean age 57.7 ± 12.8 years, and 84% were men. The primary diagnosis was unstable angina in 17 (17%) patients, non-ST elevation myocardial infarction (MI) in 11 (11%), anterior or inferior ST elevation MI in 66 (66%), and postero-inferior MI in six (6%). Fragmented QRS was present in 30 (30%) patients during the first admission, which increased to 44% at the 2-month follow-up and to 53% at the 6-month follow-up. The presence of various coronary risk factors and drug therapy given, including fibrinolytic agents, had no effect on development of fragmented QRS. Mortality was significantly higher (P = 0.032) and left ventricular ejection fraction was significantly lower (P = 0.001) in the fragmented QRS group at the 6-month follow-up.
Conclusion: This study strongly suggests that fragmented QRS on initial presentation with acute coronary syndrome is not predictive of subsequent events but, if present 6 months later, could be predictive of an adverse outcome.

Keywords: acute coronary syndrome, fragmented QRS, electrocardiography, mortality, left ventricular function