Use of multiple arterial grafts and its effect on long-term outcome

Contemporary Coronary Graft Patency: 5-Year Observational Data From a Randomized Trial of Conduits

BACKGROUND

The Radial Artery Patency and Clinical Outcomes (RAPCO) study has enrolled patients into two trials to compare the radial artery with the free right internal thoracic artery (if age <70 years) or with saphenous vein (if age >70 years) when grafted onto the largest target other than the left anterior descending artery. Patency outcomes in RAPCO will focus only on the trial graft in each case. However, postoperative angiography from this ongoing study has reassessed all coronary grafts, both trial and nontrial: together these offer a valuable observational overview of likely graft patency in the current era in predominately asymptomatic patients, in contrast to symptom-directed studies that may overestimate the incidence of graft failure.

METHODS

Protocol-directed percutaneous angiography has been performed at intervals weighted toward the end of the study period, or earlier when directed by symptoms. To date, 184 patients have been studied as per protocol, at time points up to 10 years (mean, 3.9), among whom there are 430 nontrial grafts in addition to the 184 trial grafts. Supplementary angiography (percutaneous or computed tomography) was offered at a fixed 5-year time point postoperatively: at this juncture, 193 trial grafts and 469 nontrial grafts have been imaged. Three masked investigators report grafts as angiographically successful if patent from proximal to distal anastomosis inclusive. Failed grafts include greater than 80% stenosis, string sign, or occlusion.

RESULTS

In staggered protocol-directed angiography, overall patency of the in-situ internal thoracic artery grafts and free arterial grafts was 95.5% (210 of 220) and 91.4%% (150 of 164), respectively, which did not differ significantly (p = 0.13). Saphenous vein graft patency was 83.0% (191 of 230) with a trend to higher failure rate compared with free arterial grafts (p = 0.07), and was significantly lower than that of in-situ internal thoracic artery grafts (p = 0.01). At the optional 5-year time point, outcomes are similar to the protocol-directed findings, with patency of in-situ left and right internal thoracic artery grafts of 95.8% (204 of 213), which was significantly greater than that of the other two groups (p = 0.02 and p < 0.001). Patency of free arterial conduits and saphenous vein grafts was 89.1% (139 of 156) and 82.4% (201 of 244), respectively, which did not differ significantly (p = 0.09) at 5 years.

CONCLUSIONS

Although trending to superior patency compared with vein grafts, free arterial conduits have not matched the gold standard achieved by in-situ internal thoracic arteries at trial midpoint. Until the results from RAPCO are available, which will test types of free arterial graft against each other and will compare radial and vein grafts in the longer term, these observational data justify for now our current practice of maximal use of in-situ conduits supplemented by free radial grafts.

Surgical treatment of coronary multivessel disease

Coronary artery bypass grafting has had a significant impact on the treatment of angina, and has been the 'gold standard' since 1969. Its use and efficacy has been increased by revascularization in cardiac arrest and the use of the internal mammary artery. In parallel, catheter techniques have evolved by means of balloon dilatation and additional stenting. This has effected the referral to surgery despite the development of new arterialization techniques and minimally invasive surgery. As competing techniques, an acceptable equilibrium between surgery and stenting will be found within the next years.

Total Arterial Revascularization is Safe: Multicenter Ten-Year Analysis of 71,470 Coronary Procedures

BACKGROUND

The purpose of this study was to assess the use of arterial revascularization and to compare the in-hospital mortality with other CABG grafting strategies.

METHODS

A total of 71,470 CABG patients (1992-2001) in 27 centers in the United Kingdom were studied. The proportion of patients with arterial revascularization was compared. In-hospital mortality was compared for various grafting strategies: all-arterial (n = 5,401), all non-all-arterial patients (n = 66,069), one artery any number of veins (n = 49,801). The groups were compared for in-hospital mortality using multivariate logistic regression to assess the independent effect of the grafting strategies on mortality; logistic EuroSCORE-predicted mortality was compared to actual mortality, and all arterial and one artery and veins patients were compared with propensity score analysis.

RESULTS

There was a significant increase in the proportion of all-arterial patients over time (3.2% to 11.7%, p < 0.001) with evidence of variability across centers. Crude mortality for all-arterial patients was 2% vs 3% for all non-all-arterial patients (p < 0.001). In multivariate analysis, all-arterial was associated with a slight but insignificant increase in in-hospital mortality (odds ratio [OR] 1.13; [95% confidence interval {CI} 0.86-1.48], p = 0.36). There was a trend toward higher mortality in the all-arterial group when compared with the one artery and veins group (OR 1.19 [95% CI 0.91-1.56], p = 0.10). The one artery and veins group was the only group where actual mortality was significantly lower than predicted by EuroSCORE (p < 0.001). In propensity analysis the mortality was 1.51% for one artery and veins and 1.74% of all-arterial patients (p = 0.56).

CONCLUSIONS

The use of arterial grafting has increased over time, varies by center, and appears to be safe in terms of in-hospital mortality.