Grafting with the radial vein: an underrated option in CABG surgery?

Coronary artery bypass graft (CABG) procedures using the radial artery as a conduit were superior to a free right internal thoracic artery (RITA) and a saphenous vein graft (SVG), the RAPCO trial shows.

Considering bypass grafting to the left anterior descending artery, the use of the internal thoracic artery is the long-accepted primary choice. “But controversy exists on the choice for the second conduit,” stated. The RAPCO trial (NCT00475488) consisted of 2 separate integrated trials that compared the use of the radial artery versus the free right internal thoracic artery (RAPCO-RITA) and, separately, the radial artery versus a saphenous vein graft (RAPCO-SVG). Prof. Hare presented the 15-year clinical outcomes.

RAPCO-RITA randomised 394 participants, under 70 years of age (under 60 years of age for those with diabetes) 1:1 to radial artery or free RITA grafting. The baseline data showed a mean age of participants of 59 years, around 10% were women, and 11% of participants had diabetes. The composite clinical outcome of major adverse cardiac events (MACE) consisted of all-cause mortality, acute myocardial infarction, and/or repeat coronary revascularisation.

The rate of MACE was significantly reduced by the use of radial artery versus RITA with a hazard ratio of 0.74 (95% CI 0.55-0.97; P=0.04). “Looking at the composition of the MACE, all-cause mortality, which had an absolute reduction of 8% after 15 years and a relative risk reduction of 31%, probably predominates in the MACE calculation,” Prof. Hare elaborated.

In RAPCO-SVG, 225 participants were included, and, in line with the somewhat different inclusion criteria, the mean age was around 73 years, 19% were women, and 45% of participants had diabetes. After allocation to grafting with either a radial artery or SV, the rate of MACE was again significantly lower with radial artery grafting versus SVG: HR 0.71 (95% CI 0.52-0.98; P=0.04) at 15 years.

Prof. Hare mentioned that, currently, less than 10% of the 200,000 annual coronary artery bypass surgeries performed in the US involve radial artery grafts. From the RAPCO trial results, he suggested that all isolated CAGB operations should consider using a radial graft and assess if it is suitable and can be used without contraindications. “Whether radial grafts also perform better than current methods in instrumented procedures, however, needs to be further researched,” closed Prof. Hare.

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   1. Hare DL, et al. Radial artery patency and clinical outcomes (RAPCO) randomised trials - The 15-year clinical outcomes comparing radial artery with right internal thoracic artery or with saphenous vein grafting. LBS.03, AHA Scientific Sessions 2022, 05–07 November, Chicago, USA.

 

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Posted on 11 January, 202331 January, 2024