Table II.
Overview of Studies of Renal Sympathetic Denervation for Resistant Hypertension
| Study/Location/Funding Source | Design | Patient Characteristics | Intervention Description | Follow‐Up Duration: No. |
|---|---|---|---|---|
| Ukena (2011) 9 Location: Germany Funding Source: Not declared | Randomized controlled (N=37) | Mean age: 59.1±9.4; women: 32%; BMI: 31.8±5.2; DM: 43%; eGFR: 70±24; diuretics: 89%; average number of antihypertensive medications: 5.9±1.4 | Patients recruited from Symplicity HTN‐2 trial. Methods of denervation not specified separately | 3 mo: no loss to follow‐up reported |
| Control (N=9) | Mean age: 64.9±6.4 y; women: 21%; BMI: 30.2±4.6; DM: 22%; eGFR: 64.5±16; diuretics: 78%; average number of antihypertensive medications: 5.0±1.2 | 3 mo: no loss to follow‐up reported | ||
| Symplicity HTN‐2 (2010) 10 Location: Australia Funding Source: Ardian Inc | Randomized controlled (N=52) | Mean age: 58±12 y; women: 35%; BMI: 31±5; DM: 40%; eGFR: 77±19; diuretics: 89% (aldosterone antagonist: 17%); average number of antihypertensive medications: 5.2±1.5 | 4–6 Ablations on bilateral renal arteries, duration of ≤2 min at a maximum power of 8 W. Heparin used to maintain activated clotting time of >250 s | 6 mo: 49 renal Duplex imaging (6 months): 37 MRI (6 mo): 5 CTA (6 mo): 5 |
| Control (N=54) | Mean age: 58±12 y; women: 50%; BMI: 31±5; DM: 28%; eGFR: 86±20; diuretics: 89% (aldosterone antagonist: 17%); average number of antihypertensive medications: 5.2±1.5 | 6 mo: 51 | ||
| Mahfoud (2012) 14 Location: Germany Funding source: First author supported by Deutsche Forschungsgemeinschaft (KFO 196) | Case control (N=88) | Mean age: 61.6±1.1 y; women: 39%; BMI: 29.69±0.8; DM: 17%; cystatin C GFR (mL/min): 84.6±3.6; Diuretics: 100% (aldosterone antagonists: 33%); average number of antihypertensive medications: 5.8±0.2 | ≤8 Ablations for 2 min each in each renal artery. Heparin used to maintain activated clotting time of >250 s | 3 mo; 6 mo: no loss to follow‐up reported |
| Control (N=12) | Mean age: 61.9±3.6 y; women: 42%; BMI: 28.1±1.9; DM: 33%; cystatin C GFR: 97.9±7.4; diuretics: 100% (aldosterone antagonists: 33%); average number of antihypertensive medications: 4.9±0.3 | 3 mo; 6 mo: no loss to follow‐up reported | ||
| Brandt (2012) 13 Location: Germany Funding source: Not declared | Case‐control (N=46) | Mean age: 63.1±10.2 y; women: 33%; BMI: 28.6±3.4; DM: 46%; eGFR: 83.5±27.8; diuretics: 100%; average number of antihypertensive medications: 4.7±0.5 | ≤6 Ablations at 8 W for 2 min each were performed in both renal arteries | 1 mo; 6 mo no loss to follow‐up reported |
| Controls (N=18) | Mean age: 63.0±15.3 y; women: 39%; BMI: 28.1±3.8; DM: 39%; eGFR: 80.5±29.3; diuretics: 100%; average number of antihypertensive medications: 4.8±2.5 | 1 mo; 6 mo No loss to follow‐up reported | ||
| Mahfoud (2011) 12 Location: Germany Funding Source: Ardian Inc | Case‐control (N=37) | Mean age: 58.7±1.6 y; women: 21%; BMI: 31.3± 0.9; DM: 35%; eGFR: 75.1±3.3; diuretics: 100%; average number of antihypertensive medications: 5.8±0.2 | 6 Ablations on bilateral renal arteries, with duration of 2 min at a maximum power of 8 W. Catheter tip impedance and temperature were constantly monitored. Heparin used to maintain activated clotting time of >250 s | 1 mo: 37 3 mo: 37 |
| Controls (N=13) | Mean age: 62.5±2.9 y; women: 38%; BMI: 30.7±1.7; DM: 54%; eGFR: 81±7.6; diuretics: 100%; average number of antihypertensive medications: 5.0±0.4 | 1 mo: 13 3 mo: 13 | ||
| Krum (2009) 11 Location: Australia Funding Source: Ardian Inc | Case‐control (N=45) | Mean age: 58±9 y; women: 44%; BMI: not reported; DM: 31%; eGFR: 81±23; diuretics: 96%; average number of antihypertensive medications: 4.7±1.5 | 6 Ablations on bilateral renal arteries with a maximum duration of 2 min and energy of 8 W. Heparin used to maintain activated clotting time of >250 s | 1 mo: 41 3 mo: 39 6 mo: 26 9 mo: 20 12 mo: 9 angiograms (14–30 d): 18 magnetic resonance angiography (6 mo): 14 |
| N (controls)=5 | Mean age: 51±8 y; women: 20%; BMI: not reported; DM: 40%; eGFR: 95±15; diuretics: 60%; average number of antihypertensive medications: 4.6±0.5 | 1 mo: 5 3 mo: 5 6 mo: 5 9 mo: 5 12 mo: 5 | ||
| Bauer (2012) 15 Location: Germany Funding source: Not declared | Case series (N=11) | Mean age: 68.9±7 y; average number of antihypertensive medications: 5.6±2.1 | Not available | 6 mo: 11 |
| Hering (2012) 25 Location: Australia Funding Source: National Health and Research Council of Australia and the Victoria Government’s Operational Infrastructure Support Program | Case series (N=15) | Mean age: 61±9 y; women: 40%; BMI: 33±8; DM: 73%; eGFR: 31.2±8.9; diuretics: 100%; average number of antihypertensive medications: 5.6±1.3 | Average of 9.9±1.5 ablation treatments using a predetermined treatment protocol as in Symplicity HTN‐1 trial | 3 months: 15 6 mo: 8 12 mo: 5 Angiography (immediately after procedure): 15 |
| Himmel (2012) 18 Location: Germany Funding Source: Not declared | Case series (N=14) | Not specified | Not described | 1 mo: 14 3 mo: 14 |
| Mabin (2012) 16 Location: South Africa Funding source: ReCor Medical | Case series (N=11) | Mean age: 55±14 y; women: 64%; BMI: not reported; DM: 27%; eGFR: not reported; diuretics: 100%; average number of antihypertensive medications: 4.5 | ≤3 Ablations on each renal artery using PARADISE catheter (ReCor Medical) with energy of up to 25–30 W for upto 50 s. Heparin used to maintain activated clotting time of >250 s | Immediate: 11 2 wk: 11 1 mo: 11 2 mo: 8 3 mo: 8 |
| Mylotte (2012) 26 Location: France Funding source: Not declared | Case series (N=35) | Mean age: 63.6±11.7 y; women: 36.5%; BMI: not reported; DM: 36.4%; eGFR <60 mL/min: 15.2%; diuretics: not reported; average number of antihypertensive medications: 4.6±1.0 | Not available | 6 mo: 35 |
| Prochnau (2012) 17 Location: Germany Funding Source: Not declared | Case series (N=30) | Mean age: 62.4±12.8 y; women: 33%; BMI: 32.4±6.8; DM: 50%; renal insufficiency (S Cr >1.4): 40%; diuretics: 97%; average number of antihypertensive medications: 6 | 6 Ablations along the length of each renal artery, with maximum of 8–13 W under continuously monitoring of impedance and temperature. Standard EP catheter (Marinr; Medtronic Inc, MN) used | 1 mo: 30 3 mo: 30 6 mo: 20 12 mo: 10 Renal ultrasound (3 and 6 mo): 20 |
| Prochnau (2012) 23 Location: Germany Funding Source: Not declared | Case series (N=12) | Mean age: 62±14.3 y; women: 25%; BMI: not reported; DM: 50%; renal insufficiency (S Cr >1.4): 33.3%; diuretics: 92%; mean number of antihypertensive medications: 5.5 | 6 Ablations on bilateral renal arteries with a maximum duration of 1 min and energy of 8–13 W. Standard EP catheter (Marinr; Medtronic Inc, MN) used | 1 mo: 12 3 mo: 12 Renal duplex scan (1 and 3 mo): 12 |
| Vase (2012) 24 Location: Denmark Funding Source: Not declared | Case series (N=9) | Mean age: 56±10 y; women: 67%; BMI: 27.5±4.7; DM: 22%; eGFR: 78±13; diuretics: 100%; mean number of antihypertensive medications: 5.4±1.4 | 4–6 Ablations on each renal artery with energy of approximately 8 W lasting 2 min each Heparin used to maintain activated clotting time of >250 s | 1 mo: 9 |
| Verloop (2012) 27 Location: The Netherlands Funding Source: Not declared | Case series (N=22) | Average number of antihypertensive medications: 3.32±1.62 | Not available | 6 mo: No loss to follow‐up reported |
| Simonetti (2011) 20 Location: Italy Funding Source: Not declared | Case series (N=5) | Mean age: 50.6 y; women: 40%; BMI: not reported; DM: not reported; eGFR: 92.5; diuretics: 100%; average number of antihypertensive medications: 5 | At least 6 ablations on bilateral renal artery, with duration of 2 min at a maximum power of 8 W | 1 mo: 5 2 mo: 5 CTA (2 mo): 5 |
| Symplicity HTN‐1 (2011) 19 Location: Australia, Europe and United States Funding Source: Ardian Inc | Case series (N=153) | Mean age: 57±11 y; women: 39%; BMI: not reported; DM: 31%; eGFR: 83±20; diuretics: 95% (aldosterone blocker: 22%); average number of antihypertensive medications: 5.1±1.4 | 4–6 Ablations on bilateral renal arteries, duration of ≤2 minutes at a maximum power of 8 W. Heparin used to maintain activated clotting time of >250 s | 1 month: 138 3 months: 135 6 months: 86 12 months: 64 18 mo: 36 24 mo: 18 CTA/MRI/Renal Duplex imaging (6 mo): 81 |
| Voskuil (2011) 21 Location: The Netherlands Funding Source: Not declared | Case series (N=11) | Mean age: 68±12 y; women: 91%; BMI: 30±8; DM: 18%; eGFR: 74±14; diuretics: 45%; Average number of antihypertensive medications: 3.1±1.5 | 4–6 Treatments of bilateral renal arteries, (distal to proximal circumferentially) with duration of 2 minutes and energy of approximately 8 W | 1 mo: 11 Angiography (immediately after procedure): 11 IVUS (immediately after procedure): 3 |
| Witkowsky (2011) 22 Location: Poland Funding Source: Ardian Inc | Case series (N=12) | Mean age: 49.5 y; women: 30%; BMI: 30.9; DM: 40%; eGFR: 81.3; diuretics: 100%; average number of antihypertensive medications: 5 | ≤6 Ablations separated both longitudinally and rotationally on bilateral renal arteries with duration lasting ≤2 min and energy of ≤8 W | 3 mo: 10 6 mo: 10 Renal duplex scan (6 mo): 10 |
Abbreviations: BMI, body mass index; CTA, computed tomographic angiography; DM, diabetes mellitus; eGFR, estimated glomerular filtration rate; IVUS, intravascular ultrasonography; MRI, magnetic resonance imaging; S Cr, serum creatinine.