The Radial Artery Patency and Clinical Outcomes trial: design, intermediate term results and future direction.

The Radial Artery Patency and Clinical Outcomes Study (RAPCO) was devised and implemented in Melbourne in order to establish the appropriate place of the radial artery in the hierarchy of conduits available to the modern coronary bypass surgeon. Designed as a biological comparison with minimisation of other confounding variables, it compares this free arterial graft with the right internal thoracic artery and saphenous vein, with all conduits used in an identical fashion in two parallel cohorts of different age ranges. Enrolment was completed in 2004 and 10-year follow-up is in progress, with mean duration of about seven years at present. The midterm clinical and angiographic results to date are reviewed here, but definitive conclusions will not be possible until full completion angiographic data is available. The trial data provides a number of potential substudies of conduits, risk factors for failure and the natural history of treated coronary disease.