Dipyridamole and Aspirin and Patency of Coronary Bypass Grafts

To the Editor: Chesebro et al. (Jan. 26 issue) report that preoperative dipyridamole and early postoperative aspirin plus dipyridamole are efficacious in improving the patency of aortocoronary vein grafts at one year.¹ Although this prophylactic antiplatelet treatment started early after surgery appears to be very promising, the evidence provided does not warrant a general therapeutic recommendation. The investigators used the “clinical efficacy” and not the “intention to treat” strategy for analysis of their data. The latter strategy, reflecting the actual situation regarding decisions in clinical practice, is the appropriate one for deducing a general therapeutic recommendation.² Only 22 per cent.