Renal denervation safely reduces blood pressure in patients with uncontrolled hypertension who continue taking antihypertensive medications, reports a trial in The Lancet.
The SPYRAL HTN-ON MED trial enrolled 487 adults with uncontrolled hypertension at 25 centers in Asia, Australia, Europe, and North America. All had uncontrolled hypertension, including an ambulatory systolic BP of 140 to 170 mm Hg despite at least 6 weeks on stable doses of one to three antihypertensive medications. After renal angiography, patients were randomly assigned to catheter-based renal denervation of the main renal arteries and branches or a sham procedure with sensory masking. All procedures were performed by an experienced proceduralist following a detailed treatment plan.
At follow-up visits, patients underwent 24-hour ambulatory BP monitoring, as well as urine and blood tests to assess adherence to prescribed medications. The current paper presents a proof-of-concept analysis of the first 80 patients treated: 38 assigned to renal denervation and 42 to the sham control procedure. The main efficacy outcome was change in ambulatory BP from baseline to 6 months, with a prespecified requirement for the patient to remain on the same antihypertensive drug regimen during this time. Major adverse events included death, ESRD, and renal artery stenosis.
The two groups had similar baseline characteristics; just over half of patients were taking three classes of antihypertensive medications. Mean 24-hour ambulatory BP was 152.1/97.2 mm Hg in the renal denervation group and 151.3/97.9 mm Hg in the sham control group.
At 6 months, the renal denervation group had significant reductions in BP measurements. Mean baseline-adjusted treatment differences in 24-hour BP were −7.0 mm Hg systolic and −4.3 mm Hg diastolic. For office BP, the differences were −6.6 and −4.2 mm Hg, respectively. Compared to the sham group, the difference in the renal denervation group was −7.4/−4.1 mm Hg for 24-hour BP and −6.8/−3.5 mm Hg for office BP.
Analysis of hourly data showed significant reductions in BP throughout the 24-hour monitoring period in patients assigned to renal denervation. The between-group differences in BP were not significant at 3 months’ follow-up. Laboratory tests showed medication adherence of about 60%, with significant variation for individual patients throughout the study. No patient in either group experienced major adverse events.
Previous studies of renal denervation for treatment of hypertension have yielded conflicting results. The recent SPYRAL HTN-OFF MED trial showed “significant and meaningful” reductions in BP in the absence of antihypertensive medications. The SPYRAL HTN-ON MED study evaluated the outcomes of renal denervation in a clinically representative situation in which this procedural approach might be integrated with continued antihypertensive drug treatment.
The results show greater reductions in BP with renal denervation compared to a sham procedure in patients with uncontrolled hypertension who continue taking antihypertensive drugs. The authors note that about half of patients did not follow their prescribed antihypertensive regimen during follow-up, even though they were aware that adherence would be monitored as part of the study [Kandzari DE, et al. Effect of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial. Lancet 2018; https://doi.org/10.1016/S0140-6736(18)30951-6].