Time-course of the changes in blood pressure and in plasma rennin activity during the first week after dilation of renal artery stenosis

We measured arterial pressure and plasma renin activity throughout the first week after a technically successful percutaneous transluminal renal angioplasty (PTRA) in 12 patients with hypertension and unilateral renal artery stenosis. Mean arterial pressure fell from 126 ± 4 to 105 ± 3mmHg within 1-2 days of PTRA and stabilized thereafter; in addition, plasma renin activity decreased sharply during the first 2 days after the angioplasty (from 5.2 ± 2.3 to 1.3 ± 0.3ng/ml per h) but continued to decline, reaching 0.8 ± 0.2ng/ml per h at the end of the study. When the antihypertensive effect of PTRA was examined in relation to baseline values of plasma renin activity, the patients with low, intermediate and high plasma renin activity showed percentage decreases in mean arterial pressure of, respectively, 6%, 16% and 19% by the sixth day of observation after the angioplasty. No overall correlation was found between the changes in arterial pressure and those in plasma renin activity induced by PTRA. These data suggest that the beneficial effect of PTRA on blood pressure can be estimated within a few days and that the reduction in the activity of the renin system is the principal but not the sole mechanism responsible for it.