In patients diagnosed as having primary aldosteronism, the differentiation of unilateral (affecting only one adrenal) from bilateral (affecting both) forms is of major clinical importance. From the treating physician’s perspective, it is vital for guiding optimal management approach: unilateral adrenalectomy for most patients with unilateral primary aldosteronism and medical treatment with agents that antagonize aldosterone action (usually spironolactone, amiloride or eplerenone) for most with bilateral primary aldosteronism. It is now clear that the patients who do the best in terms of long-term cardiovascular outcomes are those with unilateral primary aldosteronism who have undergone unilateral adrenalectomy (c.f. those with bilateral primary aldosteronism who have been treated medically). This is not particularly surprising given that this procedure rids the patient of aldosterone excess completely by removing it at its source; medical treatment can only hope to ameliorate the situation with effects that may be suboptimal at maximum tolerated doses.
