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

Abstract

Renal denervation (RDN) has emerged as a potential devicebased treatment for resistant hypertension. The authors present their experience of the use of catheter-based RDN as part of routine clinical care in two specialist hypertension clinics. Thirty-four patients with uncontrolled hypertension underwent RDN. All patients had ambulatory blood pressure (BP) monitoring and directly observed medication administration prior to the procedure to exclude white-coat hypertension and nonadherence, respectively. Overall, there was a significant change in clinic systolic BP of À15.1 mm Hg (95% confidence interval, À23.4 to À6.8; P=.001) and clinic diastolic BP of À6.2 mm Hg (95% confidence interval, À11.5 to À0.9; P=.02) 6 months postprocedure, and a nonsignificant change in daytime ambulatory BP of À5.4/ À2.9 mm Hg. Eighteen patients (51.4%) showed a significant reduction in their clinic systolic BP (≥10 mm Hg) and 16 (47%) had a significant reduction in their daytime ambulatory systolic BP (≥5 mm Hg) at 6 months. J Clin Hypertens (Greenwich). 2016;18:565-571. ª 2015 Wiley Periodicals, Inc.Hypertension is a leading cause of cardiovascular morbidity and mortality.1 Despite the availability of numerous safe and effective antihypertensive drugs, blood pressure (BP) remains uncontrolled in a significant proportion of hypertensive patients.2 Hypertension that is not controlled to target, ie, systolic BP (SBP) >140 mm Hg and/or diastolic BP (DBP) >90 mm Hg, despite treatment with at least three antihypertensive medications, is known as resistant hypertension. 3Although arbitrary, the purpose of defining this condition is to help identify those patients who may benefit from special diagnostic and therapeutic considerations. Patients with resistant hypertension are a cohort at the extreme end of the BP spectrum, and are thought to represent somewhere between 5% and 20% of the hypertensive population.2,4-7 Such patients are almost 50% more likely to experience a cardiovascular event compared with the general hypertensive population. 8Management involves a comprehensive strategy that includes addressing contributory lifestyle factors, exclusion of secondary causes of hypertension, exclusion of nonadherence, rationalization of drug regimen, and addition of further antihypertensive agents.

Spironolactone versus sympathetic renal denervation to treat true resistant hypertension

“…Even though the number of ablations has failed to predict the BP response to RDN in some leading trials [ 19 , 20 ], the median of the number of shots in this study was 10, considered within the range with better decreasing BP results [ 27 ]. The decreases in both office and 24-h SBP are also quite similar to those achieved in other trials [ 28 ].…”

Controversies Surrounding Renal Denervation: Lessons Learned From Real‐World Experience in Two United Kingdom Centers

“…Our real‐world data cannot replicate the findings of the Symplicity studies and are more reflective of the success rates seen in other European studies . The UK Renal Denervation Affiliation reported an office BP reduction of 22/9 mm Hg, with a 65% response rate, in a cohort of 253 patients from 18 centers.…”

“…Individuals with complex drug regimens or who are prescribed a greater number of medications may be particularly likely to be nonadherent and hence more vulnerable to a Hawthorne effect if enrolled in a clinical trial . Hameed and colleagues addressed this issue by using directly observed medication administration with subsequent BP monitoring to confirm adherence prior to RDN. Their cohort achieved a response rate of 51%, with an office BP reduction of −15/−6 mm Hg ( P =.01/0.2) at 6 months, which is unlikely attributable to improved medication adherence.…”

Diagnosis and management of resistant hypertension

“…Although patients were asked to keep a medication diary, adherence to medication was never formally tested by directly observed dosing24 or by urine antihypertensive drug assay,20 22 as is common in routine clinical practice 42. Although a post hoc analysis eliminating those with medication changes did not affect the primary outcome or pre-specified secondary outcomes, a substantial decrease in blood pressure in the sham group might suggest a change in patient behaviour despite self-reported documentation of medication adherence or changes in prescribed antihypertensive medication during the course of trial participation 40…”