Reappraisal of a 20-year experience with the radial artery as a conduit for coronary bypass grafting

Abstract

Objective: This study aimed at evaluating the clinical and angiographic results of the radial artery (RA) used as a coronary bypass graft over 20 years.

Methods: Clinical follow-up was obtained in 563 patients at 9.2 years. Angiographic follow-up was obtained in 351 patients with opacification of 1427 conduits, including 629 RA at 7.0 years.

Results: At 9.2 years, freedom from overall and cardiovascular death was 80.3% and 92.7%, respectively. Symptoms were: acute myocardial infarction: 2.1% (n=12); angina: 17.4% (n=98), and congestive heart failure 10.6% (n=60). Percutaneous revascularization was required in 13.5% (n=76) of cases on: native coronary (n=77), RA conduit (n=21), and other graft (n=7). Reoperation was needed in 2.3% (n=13) of cases for valve replacement (n=10) and redo coronary artery bypass grafting (CABG) (n=3). At 7.0 years, RA patency was 82.8% (521/629) and was lower than that of left internal mammary artery (IMA), 95.5% (491/514) (p<0.001); similar to right IMA, 87.9% (51/58, p=0.32); free IMA, 80.0% (44/55, p=0.60); and vein, 81.9% (140/171, p=0.77). RA patency was lower in the case of myocardial ischemia: 74.0% (174/235) versus 88.1% (347/394) in asymptomatics (p<0.001). RA patency was higher for diagonal (93.1% (95/102)) compared to circumflex (82.5% (274/332, p<0.01)) and right coronary (77.6% (146/188, p<0.001)). Calcium channel blockers had no impact on RA patency. Separating four groups at successive follow-up intervals, RA patency was: 86.2%, 81.9%, 81.4%, and 81.6% at 1.0, 5.4, 8.3, and 13.1 years, respectively.

Conclusion: CABG with the RA offered long-lasting clinical benefit. Beyond the first postoperative year during which some attrition was observed, RA patency was remarkably stable for up to 20 years.

Figure 1:

Kaplan—Meier survival following coronary bypass with the radial artery. Overall survival and freedom form cardiovascular death were 70% and 89% at 15 years respectively.

Figure 2:

Kaplan—Meier freedom from percutaneous intervention (PCI) and freedom from reoperation. Freedom from PCI and freedom from reoperation were 75% and 96% at 15 years respectively.

Figure 3:

CT angiography of radial artery grafts. (A) Maximum intensity projection with curved multiplanar reformation of a radial artery to diagonal graft at 6 years. (B) Volume rendering of a radial artery (RA) to obtuse marginal graft at 14 years.

Figure 4:

Radial artery graft patency in four equal groups (n = 137) at successive time intervals. Some attrition was observed during the first postoperative year beyond which radial artery graft patency remained stable for up to 20 years.

Figure 5:

Graphic representation of radial artery patency. Kaplan—Meier estimate showed a progressive and continuous decline as opposed to expected patency extrapolated from absolute values exhibiting an early exponential phase during the first postoperative year followed by a slow decrease thereafter.