Mechanical properties of human saphenous veins from normotensive and hypertensive patients

Background. Different reactivities of saphenous vein grafts in hypertensive and normotensive patients could lead to differences in the postoperative patency of the grafts. Methods. In saphenous vein rings isolated from remnants of aorta-coronary grafts obtained from hypertensive and normotensive patients we studied the length-tension relationship; response to high levels of potassium, norepinephrine, and epinephrine; and relaxation in response to calcium deprivation. Results. The rings from hypertensive patients were stiffer and developed more force (grams force/grams weight) than the rings from normotensive subjects to 80 mmol/L potassium (59 ± 16 versus 25 ± 5, p < 0.05) and to 1 μmol/L norepinephrine (61 ± 8 versus 36 ± 7, p < 0.05), but not to 10 μmol/L epinephrine (57 ± 11 and 54 ± 11; not significant). The rings from hypertensive patients relaxed more slowly than those of the normotensive subjects in a calcium-free medium (time to half-relaxation of 976 ± 180 versus 548 ± 81 seconds; p < 0.05). Conclusions. The saphenous vein from hypertensive patients is less distensible, slower to relax, and more reactive to at least two agonists. These differences could influence the graft’s patency and the clinical outcome.