Methods: In this retrospective study, 542 patients with a diagnose of STEMI underwent primary PCI were included. Study patients were divided into two groups according to the presence (n = 153) or absence (n = 389) of a fQRS on admission ECG.

Results: WMSI was found to be significantly higher in fQRS(+) group compared to the fQRS(-) group (P < 0.001). In multivariete analysis, WMSI was found to be an independent predictor of fQRS, and fQRS was inversely associated with LVEF. The in-hospital reinfarction (P = 0.003), MACE (P = 0.024), intraaortic balloon pump use (P = 0.014), and advanced heart failure (P < 0.001) were found to be significantly more frequent in the fQRS(+) group. The presence of fQRS on admission was found to be associated with an increase in long-term cardiovascular mortality (P = 0.028), and long-term all-cause mortality (P = 0.022).

Conclusion: WMSI was significantly related with the presence of the fQRS, which reflects the linking between impairment of regional left ventricular systolic function and the presence of severe myocardial injury in STEMI.