Correct Answer: D. Work-up for secondary causes of hypertension
Correct Answer: D. Work-up for secondary causes of hypertension
The patient presents with end-organ manifestations of long-standing undertreated hypertension, specifically, left ventricular hypertrophy (LVH), AV nicking on the fundoscopic exam, and new-onset AF. There are three indications to initiate secondary hypertension workup:1
1. The patient has resistant hypertension with three measures of systolic and/or diastolic > 150/100 in three separate readings.
2. The patient has hypertension and diuretic-induced hypokalemia.
3. The patient has new-onset paroxysmal AF with hypertension.
Selection A is not advised, as the EKG shows LVH, and it is unclear how much structural abnormality the LV has without further diagnostic testing. Selection B is not advised, as the key is to recognize that uncontrolled hypertension is a modifiable risk factor potentially driving AF. Selection C is not advised, as adding clonidine does not address the root of the issue: namely, that there is a high probability of a secondary cause to the hypertension.
Discussion. The patient’s laboratory results after the secondary workup showed a high aldosterone-to-renin ratio. (Table 2). A computed tomography scan demonstrated a 1.5 cm adrenal lesion, consistent with an adenoma of the left adrenal gland. Renal vein sampling lateralizes the functioning adenoma to the left adrenal.
Table 2: The patient’s laboratory results after initiating a secondary workup.
Test | Labs | Normal Range |
Aldosterone | 30 ng/dL | |
Renin activity | 0.2 ng/ml/hr | |
Aldosterone-to-renin ratio | 150 | ≤ 25 |
The patient has primary aldosteronism (PA), an often-overlooked cause of resistant hypertension. Its prevalence in patients referred to hypertension centers ranges from 5% to possibly 10%.2,3 Hypokalemia, though present in a minority of patients with PA, is not a reliable indicator of risk.1 Compared with essential hypertension, PA leads to more adverse effects on organs. A meta-analysis of approximately 4000 patients with PA showed a 3.5-fold higher likelihood of developing AF than those with essential hypertension.4