The RADIANCE II study: two months outcomes of a randomized trial of renal denervation versus a sham procedure for uncontrolled moderate hypertension
Reported from TCT 2022
Panos Xaplanteris reports on the outcomes of the RADIANCE II study, presented by Dr Ajay Kirtane at TCT 2022, that evaluated the outcomes of ultrasound-based renal denervation for patients with uncontrolled moderate hypertension.
Why this study? – the rationale/objective
Hypertension remains uncontrolled in as much as 50 % of patients in the United States, with even higher rates in Europe.
Catheter-based renal denervation (RDN) has the potential to ameliorate blood pressure (BP) control as its “always on” effect is not dependent on patient adherence to daily intake of medications.
Ultrasound catheter-based RDN has been proven to be safe and effective in reducing BP levels in the RADIANCE-HTN SOLO trial (patients with mild/moderate hypertension off medications) and the RADIANCE-HTN TRIO trial (patients with resistant hypertension to single-pill combination therapy).
How was it executed? - the methodology
The RADIANCE II study is an international, randomized, sham-controlled clinical trial evaluating the safety and efficacy of renal denervation in a population of uncontrolled mild-to-moderate hypertension.
- Patients aged 18–75 years with uncontrolled hypertension with a history of treatment with 0-2 antihypertensive medications were included.
- Eligible patients were asked to stop their medications for 4 weeks, and 24-hour ambulatory blood pressure monitoring (ABPM) was then performed. Those with daytime average values of ≥ 135/85 mm Hg and < 170/105 mm Hg, no prior cardiovascular or cerebrovascular events, no type 1 or uncontrolled type 2 diabetes, eGFR ≥ 40 mL/min/m2, and eligible renal artery anatomy (assessed by CT or MR angiography and subsequent renal artery angiogram) were included in the study.
- 224 patients (average age 55 years, average office BP 156/101 mm Hg) were randomized in a 2:1 fashion to either the ultrasound renal denervation or sham procedure. RDN was achieved by means of an ultrasound emitting balloon inflated in the renal arteries; the thermal damage produced by the sonification resulted in the diminution of renal nerve activity around the treated arteries.
- Addition of antihypertensive medications was allowed if specified blood pressure thresholds were exceeded.
- The primary efficacy endpoint was the change in daytime ambulatory systolic BP at 2 months; safety was also assessed. Patients and outcome assessors were blinded to treatment.
What is the main result?
- The study met its primary efficacy endpoint, as ultrasound RDN resulted in a greater reduction in daytime ABPM systolic BP as compared to the sham procedure (between-group difference of -6.3 mm Hg, P < 0.0001). This was also the case for the 24-hour ABPM systolic BP (-6.2 mm Hg, P < 0.0001), home and office systolic BP, and this effect did not differ between subgroups.
- 64 % of the treated patients had a decrease in their systolic BP of at least 5 mm Hg, and 48 % had a decrease of at least 10 mm Hg. Few patients, however, had a paradoxical increase in their systolic BP after the RDN procedure.
- As regards diastolic BP, findings were similar with a mean reduction of daytime ABPM diastolic BP of –3.9 mm Hg (P < 0.0001) as well as other metrics of diastolic BP load, with the only exception of office diastolic BP.
- Of note, there were zero major adverse events related to the procedure and renal function was not altered.
Critical reading and the relevance for clinical practice
The present study adds further evidence on the efficacy and safety of RDN using an ultrasound-emitting balloon.
Similar reductions in BP with the use of this technique had been demonstrated in resistant hypertension and mild/moderate hypertension off medications; a comparable decrease of BP across the whole spectrum of hypertensive patients seems to be the result of ultrasound-based RDN.
The blinding of patients and assessors of outcomes (but not of interventionalists performing the RDN) adds to the validity of results, while the absence of any major adverse events is reassuring.
The analyses of follow-up CT/MR angiographies of the treated renal arteries are not yet reported in detail; nonetheless, no stenoses of > 70 % were reported.
An open question to be answered by the follow-up data of the study that will extend to 5 years is the medium- and long-term BP response to treatment. Assuming a class effect of RDN procedures, and based on the 3-year results of RDN using a different catheter (SYMPLICITY HTN-3 trial presented at the same session at TCT 2022), a further improvement in BP control should be expected.
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