[Effect of the degree of revascularization on left ventricular function after aortocoronary bypass operation].
BACKGROUND: The extent of myocardial revascularisation by aortocoronary bypass surgery can only be quantitatively evaluated by using precise criteria. In this retrospective study the effect of coronary surgery on left ventricular function was analyzed. PATIENTS AND METHODS: In 161 patients, 148 male and 13 female, aged 52.5 +/- 7.0 years (33 to 69 years) with 1 (7%), 2 (38%) or 3 vessel disease (55%) the left ventricular function was analyzed by Swan-Ganz catheterization at rest and on exercise, five months before and after coronary bypass operation. Coronary artery and bypass lesions were quantified according to a new detailed score including diseased main or side branches, segment 1 to 3, type of irrigation and area reduction of the artery cross-section. Pulmonary capillary wedge pressure and cardiac index were measured and related to the grade of revascularisation (RG) and pre-operative ejection fraction (EF), classified in the groups RG1 < 50%, n = 54; RG2 50 to 74%, n = 52; RG3 > or = 75%, n = 55, EF1 < 60%, n = 30 and EF2 > or = 60%, n = 129. RESULTS: The change in pulmonary capillary wedge pressure on exercise was in RG1, RG2 and RG3 -26.2%, -29.0% and -40.9%, respectively (p < 0.001). It was significantly higher in RG2 and RG3 than in RG1. The increase in cardiac index on exercise was significant only in groups RG2, RG3 and EF2 (p < 0.005). CONCLUSION: Adequate improvement of left ventricular function can be expected when a grade of revascularisation of 50% and more is achieved.