Renal Denervation in Patients With Uncontrolled Hypertension and Confirmed Adherence to Antihypertensive Medications

Renal Innervation in Resistant Hypertension: A Review of Pathophysiology and Renal Denervation as Potential Treatment

Background

Advances in treatment and increased awareness have improved the prognosis for many patients with hypertension (HTN). Resistant hypertension (RH) refers to a subset of hypertensive individuals who fail to achieve a desired blood pressure (BP) despite concurrent use of 3 different classes antihypertensive agents, one being a diuretic, and proper lifestyle changes. The prevalence and prognosis of RH are unclear owing to its heterogeneous etiologies, risk factors, and secondary comorbidities. Previous research has provided evidence that increased renal sympathetic nerve activity (RSNA) within the renal artery contributes to RH development. Renal denervation (RDN) is a procedure that attempts to ameliorate the effects of heightened RSNA via ablation renal sympathetic fibers. BP reductions associated with RDN may be attributed to decreased norepinephrine spillover, restoration of natriuresis, increasing renal blood flow, and lowering plasma renin activity. Early clinical trials perpetuated positive results, and enthusiasm grew exponentially. However, recent clinical trials have called into question RDN's efficacy. Numerous limitations must be addressed to discern the true effectiveness of RDN as a therapeutic option for RH.

Objective

We aimed to review the current understanding of RH, the anatomy of renal arteries, physiology of RH on renal arteries, anatomical pathways of the sympathetic involved in RH, RDN as a treatment option, and all relevant clinical trials treating RH with RDN.

Methods

We piloted a MEDLINE^® database search of literature extending from 1980 to 2017, with emphasis on the previous five years, combining keywords such as “resistant hypertension” and 
“renal denervation.”

Conclusion

A plethora of information is available regarding heightened RSNA leading to RH. RDN as a possible treatment option has shown a range of results. Reconciling RDN's true efficacy requires future trials to increased sites of nerve ablation, standardized protocol, increased anatomical understanding per individual basis, stricter guidelines regarding study design, increased operator experience, and integrating the use of a multielectrode catheter.

Spironolactone versus sympathetic renal denervation to treat true resistant hypertension: results from the DENERVHTA study - a randomized controlled trial

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Objective:

Both renal denervation (RDN) and spironolactone have been proposed for the treatment of resistant hypertension. However, they have not been compared in a randomized clinical trial. We aimed to compare the efficacy of spironolactone versus RDN in patients with resistant hypertension.

Methods:

A total of 24 patients with office SBP at least 150 mmHg and 24-h SBP at least 140 mmHg despite receiving at least three full-dose antihypertensive drugs, one a diuretic, but without aldosterone antagonists, were randomized to receive RDN or spironolactone (50 mg) as add-on therapy. Primary endpoint was change in 24-h SBP at 6 months. Comparisons between treatment groups were performed using generalized linear models adjusted by age, sex, and baseline values.

Results:

Spironolactone was more effective than RDN in reducing 24-h SBP and 24-h DBP: mean baseline-adjusted differences between the two groups were −17.9 mmHg (95%CI −30.9 to −4.9); P = 0.010 and −6.6 mmHg (95%CI −12.9 to −0.3); P = 0.041, for 24-h SBP and 24-h DBP, respectively. As regards changes in office blood pressure, mean baseline-adjusted differences between the two groups were −12.1 mmHg (95%CI −29.1 to 5.1); P = 0.158 and of −5.3 mmHg (95%CI −16.3 to 5.8); P = 0.332, for office SBP and office DBP, respectively. Otherwise, the decrease of estimated glomerular filtration rate was greater in the spironolactone group; mean baseline-adjusted difference between the two groups was −10.7 ml/min per 1.73 m² (95%CI −20.1 to −1.4); P = 0.027.

Conclusion:

We conclude that spironolactone is more effective than RDN to reduce 24-h SBP and 24-h DBP in patients with resistant hypertension. Therefore, spironolactone should be the fourth antihypertensive drug to prescribe if deemed well tolerated’ in all patients with resistant hypertension before considering RDN.