Can the Number of Leads with fQRS Be Used as an Additional Tool to Detect Significant Coronary Artery Disease?

Dear editor,

We read with a great interest the manuscript by Tusun et al.1 titled “Fragmented QRS Is Associated with Improved Predictive Value of Exercise Treadmill Testing in Patients with Intermediate Pretest Likelihood of Significant Coronary Artery Disease” published on July 14, 2015 in your journal. The authors demonstrated that the frequency of fragmented QRS (fQRS) was significantly higher in patients with significant coronary artery disease (CAD) compared to nonsignificant CAD, and the presence of fQRS was significantly associated with increased risk of significant CAD in multiple logistic regression analysis. They proposed that the presence of fQRS in patients with positive exercise treadmill testing may support clinicians during the decision‐making process with regard to the referral for a coronary angiography. We would like to add some comments and contributions to this article.

Fragmented QRS is traditionally defined as an additional R wave (R’), notching of the R wave, notching of the downstroke or upstroke of the S wave, or the presence of >1R’ in ≥2 contiguous leads corresponding to a major coronary artery territory on the 12‐lead ECG.2 However, authors have recently focused on the number of fQRS derivations pattern and the number of the studies on this issue has been gradually increasing. Bekler et al.3 demonstrated that the number of fQRS leads on 12‐lead ECG on admission was found to be associated with the severity and complexity of CAD in the patients with acute coronary syndrome (ACS). In our previous study, we showed that as the number of fQRS derivation increased, the number of vessels with critical stenosis also increased significantly in patients with ACS.4 Torigoe et al.5 reported that the number of leads with fQRS was an independent predictor of cardiac death or hospitalization for heart failure in the patients with prior myocardial infarction. Finally, Ozcan et al.6 found that the number of leads with fQRS was an independent predictor of appropriate implantable cardioverter defibrillator (ICD) shocks in patients with left ventricular systolic heart failure who underwent ICD implantation for primary prophylaxis.

In this study, comparing the mean numbers of fQRS derivations of significant CAD and nonsignificant CAD groups may provide additional benefit. However, the authors did not mention such an analysis in their study. If there is a significant difference between the significant CAD and nonsignificant CAD groups in terms of the number of leads with fQRS, this result will provide additional contribution to the study. In addition, we suggest that determining a cutoff value by ROC analysis for the number of leads with fQRS to detect significant CAD may increase the importance of the study.