Does the extended used of arterial grafts compromise the myocardial recovery after coronary artery bypass grafting in left ventricular dysfunction?

Objective: To assess the prognostic factors of myocardial recovery expected after coronary bypass surgery and the impact of surgical technique used, a prospective non-randomized study including a 1-year postoperative evaluati on of left ventricular function was performed in patients with left ventric ular dysfunction (left ventricular ejection fraction (LVEF) < 0.40). Method s: From 1993 to 1996, 110 patients (mean age 61 +/- 11 years) were included in the study. The mean LVEF was 31 +/- 6%. All patients had preoperative r adionuclide investigations based on the combination of stress/reinjection t hallium single photon emission computed tomography (SPECT) and planar evalu ation of LVEF; 88% of patients had reversible ischemic thallium defects. Tw o surgical technique were used: 53 patients received the left internal mamm ary artery with associated sequential vein graft, and 57 patients received only arterial grafts, internal mammary and gastroepiploic arteries. The mea n number of distal anastomoses was 3.2 +/- 0.8 and 54% of patients had comp lete revascularization. At 1 year, all survivors had clinical evaluation an d the same radionuclide investigations. Results: The early mortality was 2. 7%. At 1 year, 100 patients were surviving; on average, NYHA class decrease d 1.9 +/- 0.8 to 1.4 +/- 0.6 (P < 0.01) and CCS class from 2.8 +/- 0.6 to 1 +/- 0.3 (P < 0.01). The mean LVEF increase from 31 +/- 9 to 34 +/- 10% (P < 0.01) and the mean LV end-diastolic volume decreased from 317 +/- 112 to 285 +/- 108 mi (n.s.). The postoperative improvement in LV function was hig her in patients in NYHA class 3 or 4 before surgery (P < 0.05), when associ ated sequential vein graft had been used (P < 0.01), and in patients with l ow preoperative LVEF (P < 0.01). The postoperative LVEF improvement observe d was significantly correlated with the improvement in left ventricular end -diastolic (LVED) volume and the improvement in redistribution/reinjection thallium uptake. Multivariate analysis showed that the surgical technique u sed and the preoperative LVEF were independent prognostic factors of the po stoperative myocardial function recovery, with a significant positive impac t of the vein use. Conclusion: This study confirms the excellent clinical r esults of coronary artery bypass grafting (CABG) in patients with coronary artery disease and LV dysfunction; improvement in LV function can be docume nted objectively and is correlated with reperfusion of hibernating myocardi um. However, the extended use of arterial grafts does not allow to achieve the significant myocardial recovery observed with the use of one internal m ammary artery (IMA) and associated sequential vein graft; it seems to be re lated to the preoperative selection of patients, but a direct negative impa ct of arterial grafts was documented and leads to be cautious in patients w ith severe LV dysfunction. (C) 1998 Elsevier Science B.V. All rights reserv ed.