External stenting of saphenous vein grafts for coronary artery bypass: a single-center analysis of clinical outcomes

BACKGROUND: Angiographic studies have shown that external stenting reduces disease progression in saphenous vein grafts (SVG) for coronary artery bypass grafting (CABG). However, reports of clinical outcomes of external SVG stenting are limited. METHODS: We conducted a retrospective analysis using a prospectively maintained national registry to evaluate clinical outcomes in patients undergoing either isolated CABG or combined (CABG + valve) procedures with use of an external SVG stent between December 2015 and December 2019. Median follow-up was 36.2 months (IQR: 24.4-41.6 months). The primary endpoint was ischemia-driven target vessel revascularization at 1 year. Secondary endpoints included all-cause death, non-fatal myocardial infarction (MI), stroke, and the composite of death, non-fatal MI or stroke at 1 year. Kaplan-Meier rates of survival, freedom from the composite of death, non-fatal MI or stroke and freedom from repeat revascularization were calculated at 3 years. RESULTS: The study population included 74 patients (isolated CABG, N.=61; combined procedure, N.=13). Mean age was 65.5±9.2 years, and 81% were male. External stenting of one SVG was performed in 63 patients (85%) and external stenting of 2 SVG in 11 patients (15%). External stenting was most frequently performed on an SVG to the right coronary artery (N.=45 patients; 53%). Ischemia-driven target-vessel revascularization occurred in 0% at 1 year. All-cause death, MI, stroke, and the composite of death, MI, or stroke at 1 year occurred in 2.7% (2/74), 0% (0/74), 1.4% (1/74), and 4.1% (3/74), respectively. At 3 years, the rates of survival, freedom from the composite of death, non-fatal MI or stroke, and freedom from repeat revascularization were 89.7% (95% CI: 78.0-95.3), 88.3% (95% CI: 76.5-94.4), and 94.8% (95% CI: 84.6-98.3), respectively. CONCLUSIONS: Clinical outcomes with external SVG stenting are excellent without ischemia-driven target-vessel revascularization at 1 year, and low rates of repeat revascularization at 3 years. Further follow-up will show whether external stenting reduces SVG failure with a benefit on long-term clinical outcomes.