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Recent estimates indicate that 8-12% of patients with hypertension do not respond adequately to optimal medical therapy. Sympathetic renal artery denervation is emerging as a viable treatment option for patients with drug resistant HTN but long-term results using multi-electrode ablations systems have not been reported.
Methods and Results
The EnligHTN renal denervation system (St Jude Medical) has 4 electrodes attached on a basket mounted at the tip of the catheter and can deliver multiple transmural lesions in a predetermined pattern. The EnligHTN-I first-in-human study was designed to assess the safety and efficacy of this multi-electrode ablation system in patients with drug-resistant hypertension. A total of 46 pts (av. age 60±10yrs, on 4.8±0.6 meds) were enrolled. Of these pts 33% were female, 98% were white, 20% had Coronary Artery Disease, 59% had hyperlipidemia, 33% had type II Diabetes Mellitus, and 30% had history of sleep apnea. On average 7.7±0.8 lesions were created in the right renal artery and 7.4±1.4 in the left. Baseline av. office BP was 176/96 mmHg and average 24 hr ambulatory BP 150/83 mmHg. Average reductions (mmHg) of office BP at 1, 3, 6 and 12 months were -28/10, -27/10, -26/10 and -27/11 mmHg (p<0.001) respectively and for 24hr ambulatory BP -10/5, -10/5 and -10/6 mmHg (p<0.001) data for 12 month N/A. At 12 months 80% of patients were responders, 75% had office BP <160 systolic and 29% had normalized BP. At 6 months there was a small reduction in the estimated glomerular filtration rate (from 87 to 82 μL/min/1.73m2) driven by a small increase in serum creatinine from 78 to 83 μmol/L), but both values returned to baseline at 12 months. Cystatin C levels and microalbuminuria improved significantly up to 12 months. There were 3 device/procedure related serious adverse events reported to date: hypertensive renal disease progression, symptomatic hypotension and worsening of pre-existing renal artery stenosis. Eighteen month efficacy and safety data will be available to be presented at the meeting.
We conclude that data demonstrates that the EnligHTN ablation system continues to be safe and effective in the treatment of patients with drug-resistant hypertension.