The Symplicity HTN-1 (n=150) was the first multicenter, proof-of-concept and safety study for patients with resistant arterial hypertension (mean age 57 years) undergoing catheter-based renal denervation. Patients in the Symplicity HTN-1 study were heavily medicated, taking an average of five antihypertensive drugs, and were still poorly controlled (office blood pressure 175/98mmHg). The primary endpoint was peri-procedural and safety of the treatment (n=45) after 1 and 12 month published in 2009 at the Lancet (1). After four weeks, a significant reduction of systolic and diastolic office blood pressure by 14 and 10mmHg has been described, which increased to 27 and 17mmHg (p=0.026) after 12 months (1). The recently presented 36 months long-term follow-up indicates a sustained blood pressure lowering effect of 32 and 14mmHg (p<0.01, n=88), making a significant functional regrowth or re-innervation of the kidneys unlikely. A drop of 10mmHg and more in systolic blood pressure (response to treatment) were seen in 93% at the final report after 3 years. One new renal artery stenosis requiring stenting and three deaths unrelated to renal denervation occurred during the 3 years of follow-up.
(1) Krum H, Schlaich M, Whitbourn R, et al. Catheter-based renal sympathetic denervation for resistant hypertension: a multicenter safety and proof-of-principle cohort study. Lancet 2009;373:1275-81.
Renal denervation (RDN) with radiofrequency ablation substantially reduces blood pressure in patients with treatment-resistant hypertension. We assessed the long-term antihypertensive effects and safety.
Symplicity HTN-1 is an open-label study that enrolled 153 patients, of whom 111 consented to follow-up for 36 months. Eligible patients had a systolic blood pressure of at least 160 mm Hg and were taking at least three antihypertensive drugs, including a diuretic, at the optimum doses. Changes in office systolic blood pressure and safety were assessed every 6 months and reported every 12 months. This study is registered with ClinicalTrials.gov
, numbers NCT00483808
, and NCT00753285
88 patients had complete data at 36 months. At baseline the mean age was 57 (SD 11) years, 37 (42%) patients were women, 25 (28%) had type 2 diabetes mellitus, the mean estimated glomerular filtration rate was 85 (SD 19) mL/min per 1·73 m2, and mean blood pressure was 175/98 (SD 16/14) mm Hg. At 36 months significant changes were seen in systolic (−32·0 mm Hg, 95% CI −35·7 to −28·2) and diastolic blood pressure (−14·4 mm Hg, −16·9 to −11·9). Drops of 10 mm Hg or more in systolic blood pressure were seen in 69% of patients at 1 month, 81% at 6 months, 85% at 12 months, 83% at 24 months, and 93% at 36 months. One new renal artery stenosis requiring stenting and three deaths unrelated to RDN occurred during follow-up.
Changes in blood pressure after RDN persist long term in patients with treatment-resistant hypertension, with good safety.
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