Ak. Andreassen et al., ENDOTHELIUM-DEPENDENT VASODILATION OF THE SKIN MICROCIRCULATION IN HEART-TRANSPLANT RECIPIENTS, Clinical transplantation, 12(4), 1998, pp. 324-332
Patients with heart failure demonstrate attenuated endothelium-depende
nt vasodilation of the peripheral circulation. while this is suggested
to be reversed after heart transplantation. However, data from human
subjects are limited and conflict with studies on the peripheral vasom
otor tone in cyclosporine-treated animals, suggesting endothelial dysf
unction. We recorded forearm skin perfusion responses following graded
iontophoresis of 1% acetylcholine (endothelium-dependent) and 1% sodi
um nitroprusside (endothelium-independent) by laser Doppler perfusion
measurements in 32 heart transplant recipients and 15 age-matched cont
rols. III addition, the hyperemic response to 3 min of blood flow occl
usion to the forearm was measured on the third finger pulp. With compa
rable baseline values, the increases in perfusion to the 4 application
s of acetylcholine were significantly attenuated in heart transplant r
ecipients compared with controls: 59 +/- 9 vs. 146 +/- 32, 242 +/- 39
vs. 492 +/- 77, 450 +/- 66 vs. 845 +/- 120 and 699 +/- 77 vs. 993 +/-
139% (mean +/- SEM; all p < 0.01). Peak hyperemia (134 +/- 4 vs. 153 /- 12 arbitrary units (AU); p < 0.05), time for the hyperemic perfusio
n to return to preocclusive baseline (52.4 vs. 102.9 s; p < 0.01) and
hence the area under the perfusion curve (1469 +/- 244 vs. 4581 +/- 92
1 AU s; p < 0.01) were reduced among heart transplant recipients. The
area under the perfusion curve correlated significantly, with mean art
erial blood pressure (r = - 0.60, p < 0.01) and with the responses to
iontophoresis of acelylcholine (r = 0.41 p < 0.01), Two non-invasive t
ests of vascular function demonstrate attenuated endothelial-dependent
microvascular responses in heart transplant recipients. The relative
impact of prior congestive heart failure and postoperative factors, su
ch as treatment with cyclosporine. remains to be determined.