Table 1.

Study criteria.

Inclusion

(i) Age 30 to 70 years

(ii) One month of stable antihypertensive treatment with at least three antihypertensive agents including a diuretic (or in case of diuretic intolerance, a minimum of three nondiuretic antihypertensive drugs)

(iii) Daytime ABPM systolic blood pressure ≥ 145 mmHg (preceded by 1 month of scheduled drug intake showing at least 85% adherence)

Exclusion

General

(i) Noncompliant personality (abuse, mental illness)

(ii) Pregnancy/inadequate contraception in fertile women

(iii) Known allergy to iodine-containing X-ray contrast agent

Comorbidity

(i) Diabetes

(ii) Secondary hypertension

(iii) Malignant disease

(iv) Congestive heart failure NYHA 3-4

(v) Chronic renal failure stages 4-5 (eGFR ≤ 30 ml/min/1.73m2)

(vi) Stable angina pectoris (CCS classes 2–4)

(vii) Unstable angina pectoris

(viii) Coronary artery disease with indication for coronary intervention

(ix) Recent myocardial infarction or coronary intervention (<6 months)

(x) Permanent atrial fibrillation

(xi) Orthostatic syncope (<6 months)

(xii) Symptomatic peripheral artery disease

Paraclinical

(i) Clinically significant abnormal electrolytes and liver function tests.

(ii) Hemoglobin < 7.0 mmol/l

(iii) Abnormal thyroid function

(iv) Macroscopic haematuria

(v) ECG: AV-block grades 2 and 3 or AV-block grades 1 + branch block

Echocardiography

(i) Left ventricular ejection fraction < 50%

(ii) Significant valvular disease

CT-angiography and selective angiography of renal arteries

(i) Pronounced calcification in iliaco-aortic or renal arteries

(ii) Multiple renal arteries: accessory renal arteries estimated to carry more than 10% of the kidney's blood supply (small polar arteries accepted) and being undersized (see below) for ablation procedure

(iii) Renal artery diameter < 4 mm

(iv) Renal artery length (from ostium to first major side branch) < 20 mm

(v) Renal artery disease (stenosis, fibromuscular dysplasia; prior intervention, dissection)