DOPPLER FLOW MEASUREMENT IN CORONARY-ARTERY BYPASS GRAFTS AND EARLY POSTOPERATIVE CLINICAL OUTCOME

The present investigation attempts to correlate flow measurements made intraoperatively in coronary bypass grafts with clinical outcome. A t otal of 352 consecutive patients undergoing isolated coronary artery s urgery underwent hemodynamic assessment of their bypass grafts (328 in ternal thoracic artery and 582 saphenous vein grafts) at the end of ca rdiopulmonary bypass (CPB) by using a 8 MHz pulsed Doppler ultrasound flowmeter. The total patient population was divided into three groups of distinct outcome (A: normal, 228 patients; B: complicated, 106 pati ents; C: poor, 18 patients) on the basis of a combination of the follo wing parameters: difficult weaning from bypass, use of inotropic drugs , reduced left-ventricular stroke work index, myocardial infarction, i ntraaortic balloon counterpulsation, and death of cardiac origin. Univ ariate analysis has shown clinical outcome to be influenced by preoper ative clinical condition and not by flow in bypass grafts (average flo w per graft [ml/min] was 60 +/- 2 [mean +/- SEM) in group A, 58 +/- 3 in group B and 43 +/- 6 in group C: NS by analysis of variance). Multi variate analysis (Fisher linear discriminant analysis) selected only t he two following factors leading to normal (group A) or adverse (group s B and C) outcome: unstable angina (p = 0.026) and duration of additi onal CPB after unclamping the aorta (p < 10(-5)). To conclude, clinica l outcome was not influenced by flow as measured in well-functioning b ypass grafts by pulsed Doppler technique.