SURGICAL-TREATMENT OF ISOLATED LEFT ANTERIOR DESCENDING CORONARY STENOSIS - COMPARISON OF LEFT INTERNAL MAMMARY ARTERY AND VENOUS AUTOGRAFTAT 18 TO 20 YEARS OF FOLLOW-UP

To assess the long-term results of the surgical treatment of isolated left anterior descending coronary artery stenosis and compare surgical strategies for graft selection, we reviewed 100 consecutive patients receiving left internal mammary artery-to-left anterior descending art ery grafts and 100 consecutive patients who received a saphenous vein autograft to the left anterior descending artery. All patients underwe nt operation from 1971 through 1973. The internal mammary artery and s aphenous vein graft groups were equivalent with regard to preoperative clinical and angiographic variables, except that patients receiving l eft internal mammary artery grafts had a higher prevalence of noncriti cal disease (less than 50 % stenosis) in the circumflex and right coro nary arteries than did the saphenous vein graft group. Mean follow-up for the internal mammary artery and saphenous vein graft groups was 18 .7 years and 20.7 years, respectively. The 18-year outcome was superio r for the internal mammary artery group. Cox regression analysis confi rmed that patients with left internal mammary artery grafts had superi or survival, intervention-free survival, and event-free survival (all p < 0.01). The presence of noncritical disease in other vessels advers ely affected intervention-free survival and event-free survival for bo th groups (all p < 0.03) and decreased survival for the saphenous vein graft group (p = 0.01) but not for the internal mammary artery group (p = 0.24). We conclude that in long-term follow-up of surgically trea ted isolated left anterior descending artery stenosis (1) the left int ernal mammary artery consistently yields better overall and interventi on-free survival than does the saphenous vein graft, (2) outcome is in fluenced by the presence of noncritical disease in other vessels at th e initial operation, and (3) deployment of the left internal mammary a rtery in the treatment of isolated left anterior descending artery ste nosis yielded 18 years of intervention-free survival of 60.5 % and pro vides a standard for comparison with other forms of therapeutic interv ention.