Resolution of Drug-Resistant Hypertension by Adrenal Vein Sampling-guided Adrenalectomy: A Proof-of-Concept Study

Drug-resistant hypertension (RH) is a very high-risk condition involving many hypertensive patients, in whom primary aldosteronism (PA) is commonly overlooked. Hence, we aimed at determining if 1) adrenal vein sampling (AVS) can identify PA in RH patients, who are challenging because receiving multiple interfering drugs; 2) AVS-guided adrenalectomy can resolve high blood pressure resistance to treatment in these patients. Based on a pilot study we selected from 1016 consecutive patients referred to our Centre for "difficult-to-treat" hypertension those with RH, for an observational prospective cohort study.  We excluded those non-adherent to treatment (by therapeutic drug monitoring) and those with pseudo-RH (by 24h blood pressure monitoring), which left 110 patients who met the ESC/ESH 2013 definition for RH.  Of these patients, 77 were submitted to AVS, which showed unilateral PA in 27 (mean age 55 years; male/female 19/8).  Therefore, these patients underwent AVS-guided laparoscopic unilateral adrenalectomy, which resolved RH in all: 20% were clinically cured in that they no longer needed any antihypertensive treatment; 96% were biochemically cured.  Systolic and diastolic blood pressure fell from 165/100±26/14 mmHg at baseline, to 132/84±14/9 mmHg at 6 months after surgery (p<10-4for both) notwithstanding the fall of number and defined daily dose of antihypertensive drugs required to achieve blood pressure control (p <10-4 for both).  A prominent regression of cardiac and renal damage was also observed. Thus, this study shows the feasibility of identifying PA by AVS in RH patients, and of resolving high blood pressure resistance to treatment in these patients by AVS-guided adrenalectomy.