Correlation of QRS duration with myocardial blush grade as a marker of myocardial reperfusion in primary percutaneous coronary intervention

BACKGROUND: The association between duration of QRS and myocardial reperfusion is not very well established. Our aim was to assess the relationship between measurements of QRS duration and myocardial blush grade (MBG) in patients with ST-elevation myocardial infarction (STEMI) who were treated with a primary percutaneous coronary intervention (PCI). METHODS: Between January 2016 and June 2017, 200 patients with STEMI who presented within 12 h of symptom onset and taken up for primary PCI were analyzed with electrocardiogram (ECG) before and after the procedure. Two study groups were then defined on the basis of microvascular perfusion: group A (MBG 0-1) and group B (MBG 2-3). RESULTS: Group A had a total of 80 patients, and group B had 120 patients. The baseline characteristics were similar in the two groups. QRS duration was found to be longer in group A compared with group B at both the immediate ECG (95.5 ± 15.63 vs 80.87 ± 12.80 msec, p < 0.001, respectively) and at the 60th minute ECG (96.95 ± 16.2 vs 78.82 ± 12.08 msec, p < 0.001, respectively) post angioplasty. Significant difference was detected between the two groups post-angioplasty at both the immediate (10.99 ± 10.05 vs −6.64 ± 10.61 msec, p < 0.001) and the 60th minute (13.03 ± 11.64 vs −7.95 ± 11.11 msec, p < 0.001) ECG. Using receiver operator curve analysis, we found that QRS complex narrowing of 4.5 msec post angioplasty was the best cutoff value for predicting reperfusion. CONCLUSION: QRS duration change post angioplasty is strongly correlated with the myocardial reperfusion in patients presenting with STEMI.