The risk factors for radial artery and saphenous vein graft occlusion are different.

Objectives. To determine risk factors for radial artery and saphenous vein graft occlusion during long-term follow-up after coronary artery bypass grafting (CABG). Methods: From a cohort of 119 patients who had received a radial artery graft, 76 - of whom 55 also had at least one saphenous vein graft - underwent a preplanned direct angiography and anthropometric, biochemical, and endothelial function assessment 7.6-12.1 (mean 8.9) years after CABG. Comorbidity, medication, and smoking habits were also recorded. The association between these parameters and conduit longevity was analyzed in univariable and multivariable logistic regression models. Results: Radial artery graft occlusions were associated with higher plasma levels of high-sensitive C-reactive protein and patency was best among patients with pharmacologically treated hypertension. The sole independent risk factor identified for saphenous vein graft occlusion was tobacco smoking 8-12 years postoperatively. Conclusion: Our data support the contention that the pathogenesis of radial artery graft failure is distinct from vein graft disease and is related to hypertension status and systemic inflammation. These risk factors are potential targets for preventive measures. Accordingly, the study supports the eventual design of personalized secondary prevention regimens.Clinical registration number: ISRCTN23118170.

Drug-Eluting versus Bare-Metal Stents in Saphenous Vein Grafts Compared to Native Coronary Vessels: The Norwegian Coronary Stent Trial Study.

BACKGROUND: Drug-eluting stents (DES) reduce target lesion revascularization (TLR) with no effect on mortality or myocardial infarction (MI) compared to bare-metal stents (BMS) in native vessels. Randomized stent studies in saphenous vein grafts (SVG) are few and the reported effects are ambiguous. The Norwegian Coronary Stent Trial study is the first to randomize lesions to percutaneous coronary intervention in native vessels and SVG. AIMS: The aim of this study was to compare the rate of mortality, MI, and TLR across stent and vessel types. METHODS: In this substudy, 6,087 patients with a single lesion in native vessels and 164 in SVG were followed for 5 years. RESULTS: MI was more frequent in SVG (subdistributional hazard ratio [SHR] 4.95 (3.75-6.54, p < 0.001), but not affected by stent type. In the first 500 days, DES reduced TLR in native vessels (SHR 0.21 (0.15-0.30) p < 0.001) and SVG (SHR 0.18 (0.04-0.80) p = 0.02). Thereafter, DES and BMS were equivalent in native vessels, but DES had a higher TLR rate than BMS in SVG (SHR 3.31 (1.23-8.94) p = 0.02). After 5 years, the TLR rate was still significantly lower for DES in native vessels (3.2% vs. 7.8%, p < 0.001) but not in SVG (21.4% vs. 18. 4%). CONCLUSION: In SVG, no difference in TLR between DES and BMS was observed after 5 years in contrast to persistent benefit in native vessels. The high rate of TLR and MI in SVG makes treatment of native vessels a preference whenever feasible and better treatment options for SVG are warranted.

Direct angiography demonstrates equal 8-12 years patency rates of radial artery and saphenous vein grafts.

Objectives: The benefits of coronary artery bypass surgery depend on lasting graft patency. To aid rational graft selection, the relative long-term merits of radial artery and saphenous vein grafts need to be determined by a gold standard method and with minimal clinically driven selection bias. Methods: The patency rates of various conduits were determined by direct angiography in 76 patients from a cohort of 119 undergoing coronary artery bypass grafting 7.6-12.1 (mean 8.9) years before. Results: 14 out of 76 radial artery and 10 out of 61 saphenous vein grafts were occluded (rates 0.18 and 0.16, respectively). Conclusion: The high long-term patency rate of saphenous vein grafts does not support a preferential use of the radial artery as a coronary artery bypass conduit. Clinical registration number: ISRCTN23118170.

Drug-Eluting or Bare-Metal Stents for Coronary Artery Disease.

BACKGROUND: Limited data are available on the long-term effects of contemporary drug-eluting stents versus contemporary bare-metal stents on rates of death, myocardial infarction, repeat revascularization, and stent thrombosis and on quality of life. METHODS: We randomly assigned 9013 patients who had stable or unstable coronary artery disease to undergo percutaneous coronary intervention (PCI) with the implantation of either contemporary drug-eluting stents or bare-metal stents. In the group receiving drug-eluting stents, 96% of the patients received either everolimus- or zotarolimus-eluting stents. The primary outcome was a composite of death from any cause and nonfatal spontaneous myocardial infarction after a median of 5 years of follow-up. Secondary outcomes included repeat revascularization, stent thrombosis, and quality of life. RESULTS: At 6 years, the rates of the primary outcome were 16.6% in the group receiving drug-eluting stents and 17.1% in the group receiving bare-metal stents (hazard ratio, 0.98; 95% confidence interval [CI], 0.88 to 1.09; P=0.66). There were no significant between-group differences in the components of the primary outcome. The 6-year rates of any repeat revascularization were 16.5% in the group receiving drug-eluting stents and 19.8% in the group receiving bare-metal stents (hazard ratio, 0.76; 95% CI, 0.69 to 0.85; P<0.001); the rates of definite stent thrombosis were 0.8% and 1.2%, respectively (P=0.0498). Quality-of-life measures did not differ significantly between the two groups. CONCLUSIONS: In patients undergoing PCI, there were no significant differences between those receiving drug-eluting stents and those receiving bare-metal stents in the composite outcome of death from any cause and nonfatal spontaneous myocardial infarction. Rates of repeat revascularization were lower in the group receiving drug-eluting stents. (Funded by the Norwegian Research Council and others; NORSTENT ClinicalTrials.gov number, NCT00811772 .).

Arterial grafts do not counteract target vessel occlusion.

OBJECTIVES: Grafted, non-occluded coronary arteries might contribute substantially to the myocardial blood supply and serve as a basis for vascular collateralization which preserves the myocardium in the event of graft occlusion. Early studies indicated that grafting with saphenous vein, but not internal mammary arteries, accelerates coronary atherosclerosis. This has not been extensively studied for the radial artery, which like the internal mammary artery (IMA) is largely resistant to atherosclerosis. A differential effect of various grafts might facilitate identification of disease-modifying principles. Our surgical cohort represented an opportunity to analyse new native coronary occlusions by comparison with preoperative angiograms. METHODS: One hundred and two patients underwent angiography 1.3-3.9 years after coronary artery bypass surgery, primarily in order to compare the patency of radial artery, IMA and saphenous vein grafts. RESULTS: Out of 290 stenotic, grafted vessels, 67 (23%) occluded during follow-up. Native occlusion occurred in 47% of the patients and correlated with serum-cholesterol. In a per target analysis, independent predictors of postoperative native occlusion were the right coronary artery territory, patent corresponding graft, the corresponding graft being an IMA and end-to-side anastomosis. CONCLUSIONS: Target vessel occlusion is similar with radial artery and saphenous vein grafts and proceeds rapidly even in the current era of secondary prophylaxis against atherosclerosis. Competitive graft flow appears to promote occlusion. Contrary to previous studies, we do not find vein grafts to be inferior to IMA grafts with respect to preservation of native vessel patency.

Radial artery graft patency relates to gender, diabetes mellitus and angiotensin inhibition.

UNLABELLED: The radial artery is resistant to atherosclerotic degeneration and therefore appears more attractive for coronary artery bypass grafting than the saphenous vein. However, the patency of radial artery grafts varies widely among studies. Therefore, before deciding whether to adopt this as the conduit of choice second to internal mammary artery grafts, we have prospectively monitored our first cohort of patients with radial-to-coronary bypasses. DESIGN: Angiographic and clinical outcome parameters were registered for the 119 patients receiving radial artery grafts at our institution during April 4, 2001 to October 7, 2003. RESULTS: Reangiography of 102 patients (86%) showed that after two to three years, 79% of the radial artery and 87% of the saphenous vein grafts remained patent. Radial artery harvesting was well tolerated. Patency of radial artery grafts was correlated to diabetes mellitus (detrimental), gender (women had higher occlusion rates), and use of angiotensin inhibiting medication (beneficial). CONCLUSIONS: The pre-study assumption that radial artery grafts would out-perform those of saphenous vein at mid-term is not borne out. The propensity of radial artery graft failure in diabetics and the higher patency associated with angiotensin inhibition might both relate to endothelial modulation of the muscular tone of the graft.

Coronary artery disease cannot be reliably evaluated by 16-slice multidetector spiral computed tomography.

OBJECTIVES: Angiography by selective catheterization is the standard method for coronary artery imaging but carries a risk of rare, but serious complications. We investigated whether 16-slice multidetector spiral computed tomography (MDCT) could substitute for selective angiography for evaluation of coronary artery disease in surgically revascularized patients. DESIGN: In a setting closely resembling routine clinical practice, 45 patients who had been operated with coronary artery bypass grafting 508-1135 (mean 811) days before were examined with MDCT and conventional selective angiography on the same day. The interpreters were blinded to the results of the parallel imaging modality. RESULTS: Significant pathology (stenosis >/=50% or occlusion) in the larger coronary artery segments was detected by MDCT with a sensitivity of 70-98% (mean 87%) and a specificity of 0-37% (mean 21%). MDCT failed to identify three of ten left main stem stenoses. CONCLUSION: Sixteen-slice MDCT cannot routinely replace selective angiography for evaluation of coronary artery disease.

Coronary bypass graft patency cannot be determined by multidetector spiral computed tomography.

OBJECTIVES: Angiography by selective catheterization is the reference standard for coronary bypass graft patency assessment but carries a risk of serious complications. We have investigated whether 16-slice multidetector spiral computed tomography (MDCT) can substitute for selective angiography. DESIGN: Two to three years after coronary artery bypass grafting, 45 patients with a total of 156 bypasses (100 single and 28 sequential grafts) were examined with both MDCT and conventional selective angiography on the same day. The bypasses were classified as patent, stenotic or occluded. RESULTS: The likelihood ratio for MDCT-detected occlusion was 40, reflecting a fairly high combined sensitivity and specificity. However, 24% of the distal anastomoses could not be evaluated by MDCT, mainly because of respiratory movements, artifacts due to metal clips, and small vessel dimensions. Moreover, seven out of 117 bypasses (6%) deemed evaluable by MDCT were wrongly classified by this method. CONCLUSIONS: At present, 16-slice MDCT cannot replace selective angiography for assessment of coronary bypass graft patency since 24% of bypasses could not be evaluated by this method, and an error rate of 6% is unacceptable.