The role of baseline and post-procedural frontal plane QRS-T angles for cardiac risk assessment in patients with acute STEMI

BackgroundTo our knowledge, no study so far investigated the importance of post-procedural frontal QRS-T angle f(QRS-T) in ST segment elevation myocardial infarction (STEMI). The aim of our study was to investigate the role of baseline and post-procedural f(QRS-T) angles for determining high risk STEMI patients, and the success of reperfusion. MethodsA total of 248 patients with first acute STEMI that underwent primary percutaneous coronary intervention (pPCI) or thrombolytic therapy (TT) between 2013 and 2014 were included in this study. Baseline f(QRS-T) angle was defined as the angle which measured from the first ECG at the time of hospital admission. Post-procedural (QRS-T) angle was defined according to the treatment strategy as follows: the angle which measured from the post-PCI ECG in patients treated with pPCI; the angle which measured from the ECG taken 90min after onset of therapy in patients treated with TT. ResultsThe baseline (101.9 degrees 48.0 vs. 72.1 degrees +/- 49.1, p=0.014) and post-procedural f(QRS-T) angles (95.7 degrees +/- 48.1 vs. 58.1 degrees +/- 47.1, p=0.002) were significantly higher in patients who developed in-hospital mortality than the patients who did not develop in-hospital mortality. Also, f(QRS-T) angle measured at 90min was significantly lower in patients with successful thrombolysis group compared to failed thrombolysis group (53.2 degrees +/- 42.8 vs. 77.3 degrees +/- 52.9, p=0.033), whereas baseline f(QRS-T) angle was similar between two groups (78.6 degrees +/- 53.4 vs. 78.9 degrees +/- 54.0, p=0.976). Multivariate analysis showed that post-procedural f(QRS-T) angle 89.6 degrees (odds ratio: 3.541, 95% confidence interval: 1.235-10.154, p=0.019), but not baseline f(QRS-T) angle, was independent predictor of in-hospital mortality. Conclusionf(QRS-T) angle may be used as a beneficial tool for determining high risk patients in acute STEMI. Unlike previous studies, we showed for the first time that that post-procedural f(QRS-T) can predict in-hospital mortality and TT failure.