• Renal Disease
• Hypertension & Kidney Disease
• Interventional Techniques & Devices
• Hypertensive Disease
• Cardiology Clinical Trials

• Renal Disease
• Hypertension & Kidney Disease
• Interventional Techniques & Devices
• Hypertensive Disease
• Cardiology & Cardiovascular Medicine
• Cardiology Clinical Trials

Hypertension is responsible for a significant number of preventable deaths relative to other treatable conditions, such as diabetes, breast cancer, and cervical cancer [National Committee for Quality Assurance 2003]. A. F. L. Liqui Lung, MD, Stichting Teaching Hospital, Willemstad, Curacao Island, presented results from a study showing that antihypertensive medication use was reduced following renal denervation in Afro-Caribbean descendants.

This was a pilot study conducted among 6 subjects of Afro-Caribbean descent from Curacao Island. The objectives of the study were to assess the safety and efficacy of renal artery ablation in an Afro-Caribbean population and to determine whether medication use could be reduced as a result of the procedure. In addition to being of Afro-Caribbean descent, subjects were required to have hypertension that was resistant to 4 classes of hypertensive drugs, including aldosterone blocking agents, and to be between 18 and 75 years old, with no renal artery stenosis > 5 mm, no calcification or accessory arteries, no secondary hypertension, and an estimated glomerular filtration rate > 45 mL/min. All patients had left ventricular hypertrophy diagnosed by echocardiography and evidence of microalbuminuria, putting them at high risk for cardiovascular problems.

Of the 10 patients who met the study criteria, 6 were selected for participation and flown to the Netherlands for the ablations. Participants had a mean body mass index (BMI) of 42.73 kg/m² and were a mean age of 60 years. Four patients had type 2 diabetes; 5, dyslipidemia; 1, paroxysmal atrial fibrillation; and 1, asthma.

All patients had renal nerve stimulation done before and following denervation with the electrophysiology stimulation catheter for evaluation of position and to obtain the results of denervation. The EnligHTN Renal Denervation System (St. Jude Medical, Inc.) was used for renal denervation through right femoral access and under sedation. The system delivers radiofrequency energy from an ablation catheter to create lesions along the renal nerves with the hypothesis that it may lower blood pressure.

There was no change in day or night blood pressure, BMI, or HbA1C 6 months after ablation. A positive response was defined as a 50% lowering of medication dose. For the majority of antihypertensive drugs that the patients were taking, patients either stopped taking them altogether or reduced their dose or frequency. Four of the 6 patients had a positive response. Table 1 shows the percentage drop in medication use after ablation for each patient in the study.

There were no complications. Dose reductions were required for 2 patients immediately after the intervention and for 1 patient within 48 hours of intervention due to hypotension. Neither of the patients (patients 3 and 4) with a BMI > 50 had a positive response.

Dr. Liqui Lung concluded that the pilot results suggest that renal denervation with the EnligHTN catheter may be safe and allow a reduction in antihypertensive medication in patients of Afro-Caribbean decent with drug-resistant hypertension who have a BMI <50 kg/m², dyslipidemia, and diabetes. The promising results of this pilot study will require verification in well-powered, placebo-controlled trials. Results of the blinded controlled SYMPLICITY HTN-3 trial, which showed no difference in blood pressure after renal denervation, provide cautionary data stressing the importance of controlled assessments of renal denervation strategies before wider adoption.

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