Adrenal Venous Sampling for Primary Hyperaldosteronism in Patients with Concurrent Chronic Kidney Disease

Adrenal Vein Sampling for Primary Aldosteronism: Recommendations From the Australian and New Zealand Working Group

Adrenal vein sampling (AVS) is the current recommended procedure for identifying unilateral subtypes of primary aldosteronism (PA), which are amenable to surgery with the potential for cure. AVS is a technically challenging procedure usually undertaken by interventional radiologists at tertiary centres. However, there are numerous variations in AVS protocols relating to patient preparation, sampling techniques and interpretation which may impact the success of AVS and patient care. To reduce practice variations, improve the success rates of AVS and optimise patient outcomes, we established an Australian and New Zealand AVS Working Group and developed evidence-based expert consensus recommendations for the preparation, performance and interpretation of AVS. These recommendations can be used by all healthcare professionals in a multidisciplinary team who look after the diagnosis and management of PA.

Primary Aldosteronism in Chronic Kidney Disease: Blood Pressure Control and Kidney and Cardiovascular Outcomes After Surgical Versus Medical Management

BACKGROUND

Diagnosis and treatment of primary aldosteronism (PA) in chronic kidney disease (CKD) may be deferred due to limited evidence supporting safety and efficacy of treatment. Our goal was to assess clinical outcomes in patients with PA and CKD who received surgical or medical management.

METHODS

We conducted a multicenter, retrospective cohort study of patients with PA and CKD who underwent adrenal vein sampling from 2009-2019. We characterized clinical outcomes and evaluated differences by surgical versus medical management. Primary outcomes were systolic blood pressure and number of antihypertensive medications. Secondary outcomes were diastolic blood pressure, serum potassium, estimated glomerular filtration rate (eGFR), and kidney and cardiovascular events. Analyses were adjusted for age, sex, race, cardiovascular disease, diabetes, and eGFR.

RESULTS

Of 239 participants with PA and CKD, 158 (66%) underwent adrenalectomy, and 81 (34%) were treated medically. Mean age was 57±10 years, 67% were female, mean eGFR was 45±12 mL/min per 1.73 m2, and 49% were on potassium supplementation. At 5 years, mean blood pressure decreased from 149±22/85±14 to 131±28/78±16 mm Hg and mean number of antihypertensive medications decreased from 4.0±1.5 to 2.4±1.4. Adrenalectomy, compared to medical management, was associated with similar systolic blood pressure (-0.90 mm Hg [95% CI, -6.99 to 5.07]) but fewer medications (1.7 [95% CI, -2.24 to -1.10]), and no difference in potassium levels or kidney or cardiovascular outcomes.

CONCLUSIONS

Patients with PA and CKD are likely to benefit from either surgical adrenalectomy or medical management. Detection and treatment of PA may help to reduce blood pressure and medication burden in patients with CKD.

Chronic kidney disease in adrenal disorders

PURPOSE OF REVIEW

This review will focus on hypertension due to underlying adrenal disorders in chronic kidney disease (CKD). Diagnosis of adrenal hypertension and particularly primary aldosteronism (PA) in CKD is frequently not pursued. We outline limitations that advanced kidney disease poses on the diagnostic work up of these disorders and provide a framework for approaching CKD patients suspected of having an adrenal disorder. Recognition of these disorders is important as they are often underdiagnosed which leads to poorer outcomes.

RECENT FINDINGS

Adrenal disease associated with hypertension in CKD is most commonly due to PA whereas pheochromocytoma and Cushing's disease are important but less common. Diagnosis of these diseases is important as their identification leads to better blood pressure control and can possibly mitigate the risk of progression of CKD. Work up and treatment of PA has been shown to be safe and is associated with less antihypertensive medication requirement for the associated hypertension and slower progression of CKD.

SUMMARY

This chapter summarizes the importance of recognizing adrenal hypertension in CKD and reinforces the need for physicians to pursue these diagnoses in CKD patients as this is safe and improves both BP control and delays progression of CKD.

Outcomes of drug-based and surgical treatments for primary aldosteronism

Treatments for primary aldosteronism (PA) aim to correct or prevent the deleterious consequences of hyperaldosteronism: hypertension, hypokalemia, and direct target organ damage. Patients with unilateral PA considered fit for surgery can undergo laparoscopic adrenalectomy, which significantly decreases blood pressure (BP) and medications in most cases and cures hypertension in about 40%. Mineralocorticoid receptor antagonists (MRA) are used to treat patients with bilateral PA and those with unilateral PA if surgery is not possible or not desired. Spironolactone is more potent than eplerenone, but high doses are poorly tolerated in men. MRA can be replaced or complemented with epithelial sodium channel blockers, such as amiloride. Thiazide diuretics and calcium channel blockers are used when the first-line drugs are insufficient to control BP. Dietary sodium restriction should be implemented in all cases because the deleterious consequences of hyperaldosteronism are dependent on salt loading. Several studies comparing the results of surgery and MRA have reported no differences in terms of BP, serum potassium concentration, or cardiovascular and kidney outcomes, although the benefits of treatment tend to be observed sooner with surgery. Patients with PA display relative glomerular hyperfiltration, which is reversed by specific treatment, revealing CKD in 30% of patients. However, further kidney damage is lessened by the treatment of PA.

The vascular surgeon's experience with adrenal venous sampling for the diagnosis of primary hyperaldosteronism

BACKGROUND

Adrenal venous sampling (AVS) is used to distinguish between bilateral idiopathic hyperplasia and a functional adrenal tumor in patients with hyperaldosteronism. Successful sampling from both adrenal veins is necessary for lateralization and may require more than 1 procedure. AVS has traditionally been performed by interventional radiologists; however, our goal was to examine the outcomes when performed by a vascular surgeon.

METHODS

All patients with a diagnosis of hyperaldosteronism were referred for AVS regardless of imaging findings. Cortisol and aldosterone levels were measured in blood samples from both adrenal veins. Postoperative analysis of intraoperative laboratory values before and after cosyntropin administration determined successful cannulation and sampling of each vein.

RESULTS

Between 2007 and 2012, 53 patients underwent AVS by one vascular surgeon. The average age was 54 and 63% were men. Our success rate increased with experience, because during the earlier years (2007-2010) primary and secondary success rates were 58% and 68%, respectively compared with later years (2011-2012) when primary and secondary success rates were 82% and 95%, respectively (P<0.05). Results of AVS altered localization of disease compared with what had been anticipated based on preoperative imaging and thus influenced surgical decision making in 47% of cases.

CONCLUSIONS

AVS is an important procedure in the work up of hyperaldosteronism to help identify and localize metabolically active tumors. It is an additional area in medicine where a vascular surgeon can lend expertise. Success with the procedure improves with experience and should be performed by high volume surgeons.