Vascular Remodelling and Duration of Hypertension Predicts Blood Pressure Response to Adrenalectomy in Aldosterone-Producing Adenoma Patients

Introduction: An increased media-to-lumen (M/L) ratio of resistance arteries is a hallmark of arterial hypertension and cardiovascular events. However, it remains unclear if it predicts the blood pressure response to adrenalectomy in patients with an aldosterone-producing adenoma (APA). Objective: To test the hypothesis that the M/L ratio is useful for identifying the APA patients who will benefit from adrenalectomy. Methods: We prospectively measured the M/L of 150-300 μm diameter arteries isolated from fat tissue surrounding the adrenal gland of 46 patients (18 m and 28 f, 55±12 yrs) at the time of adrenalectomy for an APA. The outcome of adrenalectomy on blood pressure was assessed by considering also the number and dosages of antihypertensive medications. Results: Adrenalectomy significantly reduced aldosterone/renin ratio (from 86±35 to 8±2) and blood pressure levels (from 163±22/99±15 mmHg mmHg to 133±15/83±8), even despite a significant reduction of antihypertensive treatment score (from 142±14 to 100±13, p<0.05). Overall, 30% of the patients were long-term normotensive without treatment and additionally 52% showed normotension despite tapered treatment. A multivariate regression analysis revealed that of several pretreatment features only the known duration of hypertension and the M/L significantly predicted the response of blood pressure to adrenalectomy. Conclusions: Adrenalectomy significantly lowers blood pressure in patients with APA and provides long-term benefit in 82%. However, a long duration of hypertension and/or the presence of vascular remodeling are associated with a lower chance of blood pressure normalisation.