LATE SURVIVAL UP TO 20 YEARS AFTER ISOLATED CORONARY-BYPASS SURGERY USING INTERNAL MAMMARY ARTERY IN PATIENTS WITH SEVERE LEFT-VENTRICULAR DYSFUNCTION

Coronary patients with left ventricular ejection fraction (LVEF) < 40% and abnormal motion of all left ventricular walls on cineangiography but without significant valve disease or left ventricular aneurysm wer e selected for this study. From january 1970 to December 1990, 155 pat ients meeting the above criteria consecutively underwent coronary by-p ass surgery; preoperatively, 149 patients had angina class III or IV, and 49 patients had dyspnea class II or III. LVEF was 31 +/- 7%. Durin g this 20-year period, two different surgical techniques have been use d: from 1970 to 1981, 79 patients (group 1) received internal mammary artery upon left anterior descending artery with associated simple sap henous grafts, under intermittent aortic cross clamping; from 1982 to 1990, 76 patients (group II) received internal mammary artery upon lef t anterior descending artery with associated sequential saphenous vein graft, under oxygenated cardioplegic myocardial protection. The mean number of by-pass was 1.6 in group I and 3.7 in group II (p = 0.001). Early mortality rate was lower in group II than in group I: 2.6% vs 7. 6% (p = 0.0 1). After a follow-up of 79 +/- 14 months, there were 51 l ate deaths, 6 patients were lost to follow-up and 90 patients were sti ll alive; 80% of all deaths were from cardiac causes, including 38% du e to heart failure. Actuarial survival rate at 5, 10, 15 years was 79 +/- 7%, 63 +/- 10%, and 36 +/- 15% respectively. The 5-year survival r ate was 71 +/- 10% in group I and 88 +/- 8% in group 11 (p = 0.02). LV EF and type of myocardial protection were independent predictive facto rs of early mortality and of late survival (p < 0.05). The late clinic al status was influenced by completeness of myocardial revascularizati on (p = 0.01). Results of coronary by-pass surgery are satisfactory in patients with severe ventricular dysfunction despite the late myocard ial deterioration observed. The best long-term results are ensured by optimal myocardial protection for survival and complete revascularizat ion for late clinical status.