title: Renal denervation with cryoenergy as second-line option is effective in the treatment of resistant hypertension in non-responders to radiofrequency ablation.
abstract: OBJECTIVE
  Renal denervation (RDN) with radiofrequency (RF) is being used to treat resistant hypertension (rHTN). As 15-30% of treated patients are non-responders to RDN, we investigated whether RDN with cryoenergy can serve as a second-line option.
  
  
  RESULTS
  Ten non-responder patients (mean age 55 years, six male) with rHTN were treated with cryoenergy for RDN. In order to qualify as non-responders, patients had to show systolic 24 hr ambulatory BP (ABP) ≥150 mmHg (median ABP 183/102 mmHg, median office- based BP [OBP] 191/108 mmHg) despite treatment with ≥4 different antihypertensive drugs (mean 6), and further not show a reduction of systolic ABP ≥10 mmHg at ≥3 months after RDN with RF. The three/six/12-month follow-up (FU) comprised clinical and biochemical evaluation, OBP and ABP measurement. Additionally, at six months, duplex sonography was performed. Cryoablation with a 7 Fr cryoablation catheter (Freezor® Xtra; Medtronic, Minneapolis, MN, USA) was performed in all patients without complications (four applications in both renal arteries, every four minutes, temperature -75°C). At three, six, and 12 months we found a reduction in systolic OBP of -41/-47/-61 mmHg (n=10/7/6; p=0.044 for all), diastolic OBP of -18/-14/-34 mmHg, systolic ABP of -38/-35/-52 mmHg (n=9/7/6, p=0.014 for all), and diastolic ABP of -20/-13/-18 mmHg (p=0.043 for all), respectively. During FU, no complications occurred and the renal function remained unchanged.
  
  
  CONCLUSIONS
  The significant reduction in systolic OBP and ABP observed qualifies RDN with cryoenergy as an effective second-line therapeutic option in non- responders to RDN with RF.
authors.affiliation: Department of Internal Medicine I, Jena University Hospital, Jena, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Prochnau
authors.forename: Stefan
authors.initials: S
authors.lastname: Heymel
authors.forename: Sylvia
authors.initials: S
authors.lastname: Otto
authors.forename: Hans-Reiner
authors.initials: HR
authors.lastname: Figulla
authors.forename: Ralf
authors.initials: R
authors.lastname: Surber
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D017115:Catheter Ablation / Q000379:methods*; D003714:Denervation / Q000379:methods*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000601:surgery*; D007668:Kidney / Q000294:innervation*; D008297:Male; D008875:Middle Aged; D017211:Treatment Failure