The effect of sequential versus multiple single saphenous vein aortocoronary bypass surgery on exercise tolerance.

The effect of aortocoronary bypass surgery on exercise tolerance in 34 patients undergoing sequential saphenous vein bypass grafts (seq. SVBG) was compared with that in 38 patients who had undergone single SVBGs. Postoperative exercise testing was carried out on average 23 months after surgery in the seq. SVBG group and 27 months after surgery in the single SVBG group (range 10-62 months in both groups). At the time of follow-up complete revascularization was demonstrated in 59% of the patients in the seq. SVBG group and in 50% of the patients in the single SVBG group. The improvement in the maximal load (MaxL) at the follow-up was 90.0% (p less than 0.001) in the seq. SVBG and 41.3% (p less than 0.001) in the single SVBG group. The corresponding increase in maximal heart rate (MaxHR) was 12.5% (p less than 0.001) and 10.1% (p less than 0.001) and the maximal ST depression (MaxSTd) diminished by 70.4% (p less than 0.001) and 54.2% (p less than 0.001). There were no statistically significant differences between the groups with respect to changes in MaxL, MaxHR and MaxSTd postoperatively. The changes in MaxL, MaxHR and MaxSTd in the completely and incompletely revascularized subgroups did not differ statistically. The exercise tolerance in this study was at least as good in the seq. SVBG group as in the single SVBG group and fully justifies continuing bypass surgery with sequential vein grafts.