Percutaneous transluminal angioplasty attenuates day-night difference in ambulatory blood pressure in renovascular hypertension

To evaluate whether the circadian rhythm of blood pressure (BP) was altered in renovascular hypertension (RVH), ambulatory BP was monitored using a noninvasive recorder in nine patients with RVH attributable to fibromuscular dysplasia before and after percutaneous transluminal angioplasty (PCTA). The circadian rhythm of BP was assessed by the day-night difference in BP and by the single cosinor method. The day-night difference in BP before PCTA was significantly greater than in age-and sex-matched normotensive subjects (n = 9, P < .01) and patients with essential hypertension (n = 9, P < .05). PCTA decreased significantly the 24-h BP as well as plasma renin activity (P < .01). In the chronogram, the BP reduction after PCTA was evident especially during the day. Accordingly, the day-night difference in BP decreased significantly after PCTA (P < .01). In the cosinor analysis, the mesor and the percent amplitude of BP decreased significantly after PCTA (P < .01). In summary, circadian rhythm of BP was preserved or rather exaggerated in RVH. The stimulated renin angiotensin system in RVH possibly contributes to the altered circadian rhythm of BP primarily by elevating the daytime BP. (C) 1997 American Journal of Hypertension, Ltd.