Fragmented QRS and mortality risk in patients with acute coronary occlusion myocardial infarction

Fragmented QRS (fQRS) is an electrocardiographic marker of myocardial injury associated with adverse outcomes in acute coronary syndromes. This study aimed to examine its prognostic value within the acute coronary occlusion myocardial infarction (ACOMI) classification framework.

We retrospectively analyzed 996 patients with Type 1a or Type 1b ACOMI-compatible ECGs. The primary endpoint was all-cause mortality. A prespecified multivariable Cox regression model with 10 covariates was used. Model discrimination was assessed using the area under the ROC curve (AUC).

fQRS was present in 237 patients (23.7%). During a median follow-up of 618 days (IQR: 398-725 days), 127 deaths occurred (12.6%). Kaplan-Meier analysis showed significantly lower survival in fQRS-positive patients (79.3% vs. 89.7%; P < 0.001). On multivariable Cox regression, fQRS was an independent predictor of mortality [hazard ratio (HR): 1.702; 95% confidence interval (CI) 1.050-2.760; P = 0.032], alongside the GRACE risk score (HR: 1.021; P < 0.001) and left ventricular ejection fraction (HR: 0.955; P < 0.001). fQRS improved model discrimination (AUC: 0.784-0.800; ΔAUC = +0.016). In the Type 1a subgroup, a signal toward increased fQRS-associated mortality was observed (HR: 1.662; P = 0.056), though this did not reach statistical significance. The fQRS × ECG type interaction was nonsignificant (P-interaction = 0.733); subgroup findings should be regarded as hypothesis-generating.

fQRS on admission ECG is independently associated with all-cause mortality in ACOMI patients and may serve as a simple adjunctive marker for risk stratification, though prospective validation is needed.