Adrenal Vein Sampling Lateralization Despite Mineralocorticoid Receptor Antagonists Exposure in Primary Aldosteronism.

Context: Many antihypertensive medications modulate the renin-angiotensin-aldosterone system, possibly skewing the diagnosis and subtyping of primary aldosteronism (PA). Particularly, mineralocorticoid receptor antagonists (MRA) might raise renin and stimulate aldosterone synthesis from nonautonomous areas, potentially obscuring lateralization on adrenal vein sampling (AVS). Withdrawal of MRA in severe PA, however, can precipitate hypokalemia and/or hypertension and therefore is not always practical. Objective: To assess the effects of MRA on the interpretation of AVS data. Design and Participants: A cohort study of all PA patients who underwent AVS at University of Michigan between January 2009 and January 2018 was conducted. Demographics, diagnostic, AVS, surgical pathology, and follow-up data were collected retrospectively.
Results: Of 191 patients who underwent AVS, 51 (27%) were exposed to MRA at the time of the procedure. Plasma aldosterone concentration and the daily defined dose of antihypertensives were higher in patients taking vs those not taking MRA. Unilateral PA was more frequent in the MRA group, both precosyntropin and postcosyntropin (P < 0.05). The MRA group included two patients with unsuppressed renin, who demonstrated unequivocal AVS lateralization. To date, 86 patients underwent unilateral adrenalectomy, including 30 patients taking MRA during AVS. The proportion of clinical and biochemical success was not statistically different between patients exposed to and those not exposed to MRA during AVS (P = 0.17 and 0.65, respectively).
Conclusion: Our data suggest that conclusive AVS lateralization is often achieved in patients with severe PA despite MRA use.