Therapeutic-Dose Warfarin (International Normalized Ratio >1.6) Plus Aspirin Improved Long-Term Patency of Saphenous Vein Graft without Bleeding Complication

Abstract

Purpose: Saphenous vein graft (SVG) is the most commonly used conduits in coronary artery bypass grafting (CABG), but the disadvantage of SVG is its tendency for progres-sive failure. We hypothesized that therapeutic-dose warfarin (international normalized ratio [INR] >1.6) plus aspirin improve SVG patency. This study aimed to evaluate the factors contributing to SVG patency. Methods: Since 2010–2020, 199 patients who underwent isolated CABG using SVG were divided into two groups according to their INR values in the first year: group T (INR >1.6) and group L (INR <1.6). Results: Group T had 162 SVGs (105 patients) and group L had 151 SVGs (94 patients). The 1-, 4-, and 7-year SVG patency rates were higher in group T than in group L (99%, 96%, and 92% vs. 93%, 86%, and 79%, respectively; p = 0.00378). The 1-, 4-, and 7-year freedom from repeat-revascularization was higher in group T than in group L (100%, 100%, and 99% vs. 98%, 95%, and 87%, respectively; p = 0.0264). Multivariate analysis showed that therapeutic-dose warfarin (p = 0.00204) and target vessel diameter (p <0.0001) were independent risk factors of SVG occlusion. Conclusion: Therapeutic-dose warfarin (INR >1.6) plus aspirin after CABG improved the long-term patency of SVG and decreased repeat-revascularization rate.