Resistive index and antihypertensive therapy in kidney transplantation

Abstract

Objectives: To investigate in kidney transplanted patients any possible correlation between intrarenal Doppler Resistive Index (RI) and arterial hypertension (AH); to detect any possible angiotensin converting enzime inhibitors (ACE-I)/angiotensin receptor blockers (ARB) influence on RI.

Material and methods: Our retrospective study took into consideration 80 consecutive renal allograft sonography scans of 54 patients (37 males) under observation in our centre over a one-year period (2003). Patients were evaluated about their renal function by means of serum creatinine dosage (mg/dL). The seriousness of AH was indirectly evaluated on the basis of the number of antihypertensive drugs taken daily.

Results: RI correlates with age (Pearson, 0.55/95% CI 0.32-0.71; p < 0.0001), and serum creatinine (Pearson, 0.58/ 95% CI 0.39-0.72; p < 0.0001). RI and serum creatinine do not differ in patient with or without ACE-I/ARB in their therapy (RI-Mann Whitney p = 0.517; creatinine-Mann Whitney, p = 0.0503). However, RI correlates with the number of antihypertensive drugs (Spearman rank correlation 0.59/95% CI 0.41-0.73; p < 0.001) and patients with three or more antihypertensive drugs in their therapy show higher RI than patients with one or no antihypertensive drugs (0.66 versus 0.8; independent samples t test, p < 0.0001).

Conclusions: in a small sample of kidney transplanted patients, RI is not influenced by ACE-I/ARB therapy, but by the amount of antihypertensive therapy.