Radial Artery Versus Saphenous Vein Patency - RSVP

Contribution To Literature:

The RSVP trial showed that among men with multivessel coronary artery disease undergoing on-pump CABG, the radial artery graft to the circumflex artery resulted in superior 5-year patency compared with the saphenous vein graft.

Description:

The goal of the trial was to compare the 5-year angiographic patency of the radial artery graft compared with the saphenous vein graft.

Study Design

  • Randomized

Inclusion criteria:

  • Patients 40-70 years of age who were scheduled to undergo "on-pump" CABG with at least 1 graft to the lateral wall of the heart
  • Patients Enrolled: 142
  • Mean Follow Up: 5 years
  • Mean Patient Age: 58 years
  • Female: 4%

Exclusions:

  • Left ventricular dysfunction (ejection fraction <25%)
  • Positive Allen’s test
  • History of Raynaud’s syndrome or vasculitis
  • Bilateral varicose veins
  • Any condition that could affect the safety of follow-up coronary angiography

Primary Endpoints:

  • Proportion of angiographically patent grafts at 5 years

Secondary Endpoints:

  • Patency was further classified as: perfect patency, <50% stenosis, >50% stenosis, severe diffuse narrowing (string sign), and total occlusion
  • Change in mortality

Drug/Procedures Used:

Patients scheduled to undergo coronary artery bypass grafting (CABG) with a 70% or greater stenosis in the circumflex artery were randomized to grafting of this vessel with a radial artery (n = 82) or a saphenous vein (n = 60). Follow-up angiography was performed at 5 years.

Concomitant Medications:

The harvested saphenous vein was distended with heparinized whole blood and the harvested radial artery with heparinized whole blood and verapamil (1 mg/10 ml). Postoperatively, all patients were treated with aspirin (150 mg daily) and diltiazem (60 mg three times daily for 6 weeks).

Principal Findings:

Out of 142 patients enrolled, 103 patients underwent 5-year angiographic follow-up. The mean number of grafts received was 3.3 in both groups. Cardiopulmonary bypass time was 96 minutes in the radial artery group and 95 minutes in the saphenous vein group. Delayed wound healing at the conduit harvest site occurred in 5% of the radial artery group and 16% of the saphenous vein group (p = 0.03). The overall 5-year survival was 94.4%.

The primary outcome, graft patency at 5 years, was observed in 98.3% of the radial artery group and 86.4% of the saphenous vein group (p = 0.04). The one radial artery occlusion and one "string sign" occurred in grafts that had been anastomosed to circumflex arteries with nonsignificant lesions.

Stenosis less than 50% was observed in 5% of the radial group versus 16% of the saphenous vein group, stenosis greater than 50% was observed in 2% versus 7%, and severe diffuse narrowing was observed in 2% versus 0%, respectively. There were five radial artery grafts with anastomotic lesions, although without disease in the body of the graft.

Pooled analysis of five randomized trials: Radial Artery Database International Alliance (RADIAL), n = 1,036, median follow-up = 10 years:

  • Mean number of grafts = 3.1
  • Death, myocardial infarction, or revascularization for radial versus saphenous vein graft (HR 0.73, p < 0.001): Among men (HR 0.84) and women (HR 0.51) (p for interaction = 0.03)
  • Death or myocardial infarction for radial versus saphenous vein graft (HR 0.77, p = 0.01)
  • Death for radial versus saphenous vein graft (HR 0.73, p = 0.01)
  • Revascularization for radial versus saphenous vein graft (HR 0.62, p = 0.004)

Interpretation:

Among men with multivessel coronary artery disease undergoing on-pump CABG, the radial artery graft to the circumflex artery resulted in superior 5-year patency compared with the saphenous vein graft.

The use of the radial artery as a bypass graft conduit has been controversial; however, this randomized trial with one of the longest angiographic follow-up durations, demonstrates the superiority of the radial artery graft. The results are applicable to the patient population studied; men with multivessel coronary disease that includes a severely stenosed circumflex artery. The harvesting technique of the conduit also merits mention: supraphysiological distention of the radial artery with heparinized whole blood and verapamil. Last, this was a single-center study that will need to be validated at other medical centers.

References:

Presented by Dr. Mario F.L. Gaudino at the American College of Cardiology Virtual Annual Scientific Session Together With World Congress of Cardiology (ACC 2020/WCC), March 30, 2020.

Collins P, Webb CM, Chong CH, Moat NE, on behalf of the Radial Artery Versus Saphenous Vein Patency (RSVP) Trial Investigators. Radial artery versus saphenous vein patency randomized trial: five-year angiographic follow-up. Circulation 2008;117:2859-64.

Keywords: acc20, ACC Annual Scientific Session, Coronary Artery Disease, Angina, Stable, Radial Artery, Saphenous Vein, Wound Healing, Constriction, Pathologic, Cardiopulmonary Bypass, Verapamil, Coronary Artery Bypass


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