Fragmented QRS Increases Risk for Ventricular Tachyarrhythmia in STEMI

Fragmented QRS (fQRS) significantly increased the risk of developing ventricular tachyarrhythmias (VTAs) in patients with ST-segment elevation myocardial infarction (STEMI), according to a meta-analysis recently published in the European Journal of Clinical Investigation.

The association between fQRS and malignant cardiac arrhythmias in patients with acute MI is well known, but no systematic reviews or meta-analyses have been conducted on this issue. The researchers conducted a meta-analysis on the predictive value of fQRS for VTAs in patients with acute MI. The online databases PubMed, Embase, and Cochrane Library were searched to identify relevant studies for the meta-analysis. To be included in the analysis, studies had to meet the following criteria: studies had to be published in English, had to be a case-control or cohort design, the end points had to be VTAs, and odds ratio or hazard ratio with 95% CI had to be published. Publication bias was accessed by analysis of a funnel plot.

A total of 422 relevant studies were identified, and of those 6 met all the selection criteria. These 6 studies comprised a total of 2218 patients with STEMI with a median age of 50 years. The 763 patients with fQRS were classified in the case group and the 1455 patients without fQRS were classified in the control group. No significant heterogeneity existed among the included studies (I²=30%). The researchers observed that the fQRS was significantly associated with the risk for VTAs in patients with STEMI with an odds ratio of 2.81 (95% CI, 1.99-3.95; P <.00001).

When the studies were divided into retrospective and prospective studies, the association remained significant for both types of studies. The association was detected in patients with fQRS with low left ventricular ejection fraction (≤50%) with an odds ratio of 2.97 (95% CI, 1.88-4.70; P <.00001), and in patients who were younger than 60 years old with an odds ratio of 3.07 (95% CI, 2.02-4.66; P <.00001). The funnel plot did not indicate publication bias.

The researchers listed several limitations, including no further analysis of specific fQRS characteristics, that important patient history-related factors were not extracted, that the included studies did not include the odds or hazard ratios after multivariate analyses, and that patients with and without primary percutaneous coronary intervention were included in the analysis.

The meta-analysis demonstrated that the presence of fQRS significantly increased the risk of developing VTAs in patients with STEMI. The authors concluded that for patients with STEMI, “fQRS on ECG also increases the risk [for] VTAs 2.81 fold.” They recommend that further studies “establish the predictive value of fQRS detail characteristics for VTAs in patients with [acute] MI.”

Reference

Xu S, Yang L, Hong D, Chen L, Wang X. Predictive value of fragmented QRS for ventricular tachyarrhythmias in patients with acute myocardial infarction: A meta-analysis [published online November 1, 2019]. Eur J Clin Invest. doi:10.1111/eci.13182