Translesional Pressure Gradients Shown to Predict Blood Pressure Response After RAS

December 3, 2010—Fabio Mangiacapra, MD, et al published findings from a study of translesional pressure gradients to predict blood pressure response after renal artery stenting (RAS) in patients with renovascular hypertension. The study was published online ahead of print in Circulation: Cardiovascular Interventions and was presented in November at the American Heart Association's 2010 Scientific Sessions in Chicago.

According to the investigators, in previous studies on the effect of RAS on arterial hypertension, patients were selected mainly on the basis of angiographic parameters of the renal artery stenosis. The aim of the present study was to evaluate whether translesional pressure gradients could identify the patients with renal artery stenosis who might benefit from stenting.

In this study, 53 consecutive hypertensive patients with unilateral renal artery stenosis who were scheduled for renal artery intervention were recruited. Transstenotic pressure gradients were measured at baseline and during maximal hyperemia before RAS. All patients had 24-hour ambulatory blood pressure measurements performed before and at 3 months after the intervention.

As detailed in Circulation: Cardiovascular Interventions, average reductions in systolic blood pressure and diastolic blood pressure at follow-up were −20 ± 30 mm Hg and −2 ± 12 mm Hg, respectively. At multivariate analysis, dopamine-induced mean gradient was the only independent predictor of the variations in both systolic blood pressure (regression coefficient, −4.03; standard error, 1.11; P < .001) and diastolic blood pressure (regression coefficient, −3.11; standard error, 1.2; P = .009). Patients who showed a decline in systolic blood pressure from the baseline value > 20 mm Hg were considered “responders.” The optimal cutoff for identifying responders was a dopamine-induced mean gradient ≥ 20 mm Hg (area under the curve, 0.77; 95% confidence interval, 0.64–0.9; P = .001).

The investigators concluded that a dopamine-induced mean pressure gradient of ≥ 20 mm Hg is highly predictive of arterial hypertension improvement after RAS, and therefore, this measurement is useful for selecting appropriate patients with arterial hypertension.