The primary patency rates at 6 months were 86.4 % for the FUSION BIOLINE heparin-coated vascular graft group compared with 70.0 % for the standard ePTFE group , a difference of 16.4 % ( 95 % confidence interval , 2.7 % -29.9 % ; P = .006 ) , and the respective rates at 12 months were 76.5 % and 67.0 % ( 95 % confidence interval , -4.8 % to 23.0 % ; P = .05 ) .