Thursday, March 13, 2014

Myocardial Tissue Perfusion Predicts the Evolution of Fragmented QRS

BACKGROUND: Fragmented QRS complex (fQRS) is associated with worse outcomes in several cardiovascular conditions.

METHODS: 401 consecutive patients with STEMI underwent primary PCI. Patients were categorized into two subgroups according to persistence or new-onset of fQRS (Group 1) and absence or resolution of fQRS (Group 2).

RESULTS: Patients in group 1 showed older age, higher rate of smoking, lower HDL-cholesterol, lower LVEF, higher angina-to-door time, higher TIMI frame count, and high rate of patients with MBG <3 compared to patients with group 2 (P < 0.05). In correlation analysis, LVEF showed positive correlation with myocardial blush grade (MBG, r = 0.448, P < 0.001) and negative correlation with the number of leads with fQRS (r = -0.335, P < 0.001). In multivariate regression analysis, new-onset or persistance of fQRS after primary PCI is significantly associated with MBG, peak CK-MBl, pre-PCI fQRS, and smoking.

CONCLUSION: Our findings showed that despite complete ST-segment resolution in all patients, fQRS is independently associated with impaired microvascular myocardial perfusion. So, fQRS, as a simple and easily available noninvasive marker, may be useful in stratification of high-risk patients with increased extent of infarcted myocardium who underwent primary PCI.

Ann Noninvasive Electrocardiol. 2014 Mar 4

COMMENT: not surprisingly, smoking was associated with higher risk