Effect of different storage solutions on oxidative stress in human saphenous vein grafts

Background Ischemia–reperfusion injury of saphenous vein grafts (SVG) during coronary artery bypass grafting surgery negatively impacts endothelial integrity and functionality and is associated with vein graft failure. The aim of this study was to evaluate the level of oxidative stress in human SVG segments following ischemic storage in three intraoperative graft storage solutions: saline (S), autologous heparinized blood (HB) and DuraGraft (DG). Methods 3 mm tissue rings derived from surplus SVG segments from 50 patients were stored at room temperature for 30 min in DG, S or HB. Total oxidative status (TOS) and total antioxidant status (TAS) levels were determined from which the oxidative stress index (OSI: TOS/TAS ratio) was calculated. A p-value < 0.017 was considered significant implementing a Bonferroni correction. Results TOS values were significantly lower for DG stored samples in comparison to both S and HB; there was no difference between S and HB (DG: 32.6 ± 1.8, S: 39.6 ± 2.8 and HB: 40.6 ± 2.4 µmol H2O2 eqv.; DG vs. S and DG vs. HB p < 0.0001, S vs. HB p = 0.047). TAS was higher for both DG and HB in comparison to S (DG: 8.9 ± 0.9, S: 6.9 ± 1.0 and HB: 8.6 ± 0.9 mmol Trolox eqv.; DG vs S p < 0.0001, DG vs. HB p = 0.263, S vs. HB p < 0.0001). OSI differed between all groups with the lowest value for DG (DG: 3.7 ± 0.2, S: 5.8 ± 0.4 and HB: 4.7 ± 0.2 µmol H2O2 eqv./mmol Trolox eqv.; all p < 0.0001). Conclusions Saphenous veins grafts stored in DuraGraft had a lower oxidative level, higher antioxidant level and a lower oxidative stress index in comparison to saphenous vein grafts stored in saline or heparinized blood. ClinicalTrials.gov Identifier NCT02922088.

Drug-eluting versus bare metal stents in saphenous vein grafts compared to native coronary vessels. The NORSTENT 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 NORSTENT study is the first to randomize lesions to percutaneous coronary intervention (PCI) in native vessels and SVG. Aims. To compare rate of mortality, MI and TLR across stent and vessel types. Methods. In this substudy 6087 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 % versus 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 myocardial infarction in SVG makes treatment of native vessels a preference whenever feasible and better treatment options for SVG are warranted.

Effect of Different Storage Solutions on Oxidative Stress in Human Saphenous Vein Grafts

Background: Ischemic injury of saphenous vein grafts (SVG) during coronary artery bypass grafting surgery negatively impacts endothelial integrity and functionality and is associated with vein graft disease and failure. The aim of this study was to evaluate the level of oxidative stress in human SVG segments following ischemic storage in three intraoperative graft storage solutions: physiological saline (PS), autologous heparinized blood (HB) and DuraGraft.Methods: 3 mm tissue rings derived from surplus SVG segments from 50 patients were stored at room temperature for 30 min in DuraGraft, PS and HB. Total oxidative status (TOS) and total antioxidant status (TAS) levels were determined and the oxidative stress index (OSI: TOS/TAS ratio) calculated. A p-value <0.017 was considered significant implementing a Bonferroni correction.Results: TOS values were significantly lower for DuraGraft stored samples in comparison to both PS and HB; there was no difference between PS and HB (DuraGraft: 32.6±1.8, PS: 39.6±2.8 and HB: 40.6±2.4 µmol H2O2 eqv.; DuraGraft vs. PS and DuraGraft vs. HB p<0.0001, PS vs. HB p=0.047). TAS was higher for both DuraGraft and HB in comparison to PS (DuraGraft: 8.9±0.9, PS: 6.9±1.0 and HB: 8.6±0.9 mmol Trolox eqv.; DuraGraft vs PS p<0.0001, DuraGraft vs. HB p=0.263, PS vs. HB p<0.0001). OSI differed between all groups with the lowest value for DuraGraft (DuraGraft: 3.7±0.2, PS: 5.8±0.4 and HB: 4.7±0.2 µmol H2O2 eqv./mmol Trolox eqv.; all p<0.0001).Conclusions: saphenous veins grafts stored in DuraGraft had a lower oxidative stress level, higher antioxidant level and lower oxidative stress index in comparison to saphenous vein grafts stored in physiological saline or heparinized blood.ClinicalTrials.gov Identifier: NCT02922088