High renin hypertension in focal renal fibromuscular dysplasia: turn off of renin system angiotensin overactivation by renal angioplasty cured high blood pressure and quickly reversed myocardial hypertrophy

Abstract. Background: Fibromuscolar dysplasia (FMD) is an idiopathic, non-atherosclerotic and non-in- flammatory stenotic lesion of renal arteries causing renovascular hypertension up-regulating renin-angioten- sin-aldosterone system. Case report: A 18-year-old man was referred to our Hypertension Center (Clinica e Terapia Medica) for the recent onset of hypertension, poorly controlled on calcium channel blockers, already associated to electrocardiographic and echocardiography signs of left ventricular hypertrophy and significant albuminuria (728 mg/24 h). An increased plasma renin activity (PRA), aldosterone level and a mild hypoka- lemia raised the suspicion of renovascular hypertension. Abdominal CT and MRI angiography showed mild kidneys asymmetry and a tubular stenosis of the right renal artery in its mid-distal portion close to renal hilum. Radionuclide renal scintigraphy documented a kidneys asymmetry of separated glomerular filtration rate. Renal FMD was diagnosed based on patient age and the absence of cardiovascular risk factors for ath- erosclerosis. Patient successfully underwent right renal angioplasty giving a rapid normalization of blood pressure levels without antihypertensive drugs. Plasma aldosterone and PRA rapidly normalized as well as serum potassium levels. Six months after angioplasty echocardiography showed a regression of left ventricular hypertrophy and the patient albumin urine excretion became normal (14 mg/24 h). Conclusions: FMD can cause renovascular hypertension associated to organ damage such myocardial hypertrophy and albuminuria through mechanisms dependent but also independent from blood pressure levels. Renal angioplasty turned off renin-angiotensin-aldosterone overactivity allowing the cure the hypertension and a surprisingly rapid reverse of myocardial hypertrophy and of excess of albumin urine excretion not only dependent on blood pressure normalization.