Increased arterial stiffness in cyclosporine-treated lung transplant recipients early after transplantation.

Background: The majority of patients undergoing solid organ transplantation develop hypertension, to which cyclosporine (CsA)-induced peripheral vasoconstriction may contribute. We hypothesized that CsA-treated transplant recipients have an increased basal vascular tone and an altered response to nitric oxide. To test this hypothesis arterial resistance, non-endothelial dependent relaxation and arterial stiffness were investigated in CsA-treated lung transplant recipients within 18 months after transplantation.

Methods: In study 1, forearm blood flow (FBF) was measured by venous occlusion plethysmography at baseline and during glyceryl trinitrate (GTN) and N(G)-monomethyl-l-arginine acetate (l-NMMA) infusion in seven lung transplant recipients and nine healthy subjects. In study 2, arterial stiffness in carotid (CCA) and radial artery (RA) was measured by ultrasound (echo-tracking) in 10 lung transplant recipients, 12 healthy subjects and six patients waiting for lung transplantation.

Results: Basal FBF (3.1 +/- 0.2 vs. 3.0 +/- 0.3 mL/min, p = 0.79) and forearm arterial resistance (36 +/- 3 vs. 33 +/- 3 mmHg/mL/min, p = 0.60) did not differ between transplant recipients and controls. GTN infusion increased and l-NMMA decreased blood flow equally in both groups. Transplant recipients had increased arterial stiffness compared to both pre-transplant patients and healthy subjects (CCA stiffness index 11.7 +/- 1.1 vs. 8.5 +/- 0.2 and 8.6 +/- 0.6, p < 0.05 both; RA stiffness index 14.7 +/- 1.5 vs. 8.9 +/- 1.3 and 10.6 +/- 0.7, p < 0.05 both).

Conclusions: Forearm blood flow and arterial resistance did not differ between healthy subjects and cyclosporine-treated lung transplant recipients early after transplantation. Increased arterial stiffness was demonstrated in transplant recipients, which may have implications for future development of transplant hypertension.