The RADial artery International ALliance (RADIAL) extended follow-up study: rationale and study protocol.
Gaudino M., Benedetto U., Fremes S., Ballman K., Biondi-Zoccai G., Sedrakyan A., Nasso G., Raman J., Buxton B., Hayward PA., Moat N., Collins P., Webb C., Peric M., Petrovic I., Yoo KJ., Hameed I., Di Franco A., Moscarelli M., Speziale G., Girardi LN., Hare DL., Taggart DP., RADIAL Investigators None.
It is generally accepted that radial artery (RA) grafts have better mid-term patency rate compared to saphenous vein grafts. However, the clinical correlates of the improved patency rate are still debated. Observational studies have suggested increased survival and event-free survival for patients who receive an RA rather than a saphenous vein, but they are open to bias and confounders. The only evidence based on randomized data is a pooled meta-analysis of 6 randomized controlled trial comparing the RA and the saphenous vein published by the RADial artery International Alliance (RADIAL). In the RADIAL database, improved freedom from follow-up cardiac events (death, myocardial infarction and repeat revascularization) was found at 5-year follow-up in the RA arm. The most important limitation of the RADIAL analysis is that most of the included trials had an angiographic follow-up in the first 5 years and it is unclear whether the rate of repeat revascularization (the main driver of the composite outcome) was clinically indicated due to per-protocol angiographies. Here, we present the protocol for the long-term analysis of the RADIAL database. By extending the follow-up beyond the 5th postoperative year (all trials except 1 did not have angiographic follow-up beyond 5 years), we aim to provide data on the role of RA in coronary artery bypass surgery with respect to long-term outcomes.