Reply to Alverez

Abstract

Dr Alverez claims that our own results show that the left internal mammary artery (LIMA) used as a composite graft to the left anterior descending (LAD) territory arteries has a higher failure rate than non composite IMA [1]. He does not appear to understand that composite IMA was grafted to the LAD territory arteries of mild or moderate stenosis more frequently than non-composite IMA. Since the degree of coronary stenosis was the most powerful predictor of patency, these two groups are therefore not directly comparable. Though long term studies are required, our short-term study strongly suggests that Dr Alverez may be in error. Arterial conduit was anastomosed to the LAD territory 174 times, Table 1. Of 89 anastomoses from composite IMA there were ten string signs in eight patients, and from non-composite IMA there were 80 anastomoses with no string signs. Indication for grafting was, moderate left main coronary stenosis with normal LAD; moderate LAD stenosis in the setting of triple vessel coronary disease; and `crossing' a distal LAD stenosis with the anastomosis resulting in minimal residual LAD stenosis. All but one of these string sign conduits were grafted to LAD stenoses #60%. Patency was 100% where coronary stenosis was $80% and all radial artery (RA) grafts were patent, irrespective of composite origin or coronary stenosis. These data compare favourably with historical studies where grafting would generally have been restricted to coronary arteries of stenosis $80%. This supports the ®ndings of the original paper that the most important in uence on patency was the degree of coronary stenosis to which a graft is competing. These eight patients were followed up for the purposes of this reply at 43:6 ^ 11:6 months postoperative. Four had further angiograms subsequent to the original paper so that angiographic follow up for all eight patients is 24:3 ^ 7:9 months. There were no new ®ndings. Seven patients European Journal of Cardio-thoracic Surgery 19 (2001) 543±544