MECHANICAL-PROPERTIES OF HUMAN SAPHENOUS VEINS FROM NORMOTENSIVE AND HYPERTENSIVE PATIENTS

Background. Different reactivities of saphenous vein grafts in hyperte nsive and normotensive patients could lead to differences in the posto perative patency of the grafts. Methods. in saphenous vein rings isola ted 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 (gra ms 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 mu mo l/L norepinephrine (61 +/- 8 versus 36 +/- 7, p < 0.05), but not to 10 mu mol/L epinephrine (57 +/- 11 and 54 +/- II; not significant). The rings from hypertensive patients relaxed more slowly than those of the normotensive subjects in a calcium-free medium (time to half-relaxati on of 976 +/- 180 versus 548 +/- 81 seconds; p < 0.05). Conclusions. T he saphenous vein from hypertensive patients is less distensible, slow er to relax, and more reactive to at least two agonists. These differe nces could influence the graft's patency and the clinical outcome. (C) 1998 by The Society of Thoracic Surgeons.