Zdravniški Vestnik (Dec 2014)
The value of corrected TIMI frame count measurements and measurements of coronary artery stenosis for predicting the flow through the coronary artery bypass
Abstract
Objectives: The aim of this retrospective study was to evaluate the prognostic value of corrected thrombolysis in myocardial infarction frame count (cTFC) measurements and different cutoff values of the degree of proximal coronary artery stenosis in a series of patients who had undergone elective isolated coronary artery bypass surgery.Methods: A retrospective analysis of 98 patients who had elective isolated coronary artery bypass surgery performed at our institution between January 2008 and March 2009 was made. Preoperatively, all patients had undergone angiography. The degree of epicardial coronary stenosis was estimated visually by the cardiologist, and cTFC of the target coronary arteries was obtained from standard projections on preoperative coronary angiograms with frame rate of 12.5 frames/s. All bypass grafts were evaluated by intraoperative transit time flow measurement (TTFM).Results: All bypass grafts were divided according to the results into four nearly equally sized groups using cTFC and percentage of proximal coronary artery stenosis. The cut-off values for both cTFC and percentage of stenosis were their median values (cTFC–14, percentage of stenosis–80 %). Bypass grafts in the four groups showed significant differences in mean flow.In group 1 (high percent stenosis and high cTFC) mean bypass graft flow was 38.3 ± 20.3 ml/min, in group 2 (low percent stenosis and high cTFC) mean bypass graft flow was 29.0 ± 15.1 ml/min, in group 3 (high percent stenosis and low cTFC) mean bypass graft flow was 48.2 ± 26.3 ml/min, and in group 4 (low percent stenosis and low cTFC) mean bypass graft flow was 35.3 ± 14.8 ml/min. Differences between individual groups were significant for all combinations except when comparing group 1 with group 4.Conclusion: Combining the data obtained from coronary angiography and TFC has shown to have a good predictive value for postoperative coronary bypass graft flow, and could thus help surgeons in making choice of target vessels for bypass surgery or help them decide whather revision of a bypass graft would be beneficial.
