***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: Renal denervation reduces office blood pressure in patients with resistant hypertension . This study investigated the effects of renal denervation on blood pressure , heart rate , and chronotropic index at rest , during exercise , and at recovery in 60 patients ( renal denervation group=50 , control group=10 ) with resistant hypertension using a st and ardized bicycle exercise test protocol performed 6 and 12 months after renal denervation .  After renal denervation  , exercise blood pressure at rest was reduced from 158±3/90±2 to 141±3/84±4 mm Hg ( P<0.001 for systolic blood pressure/P=0.007 for diastolic blood pressure ) after 6 months and 139±3/83±4 mm Hg ( P<0.001/P=0.022 ) after 12 months . Exercise blood pressure tended to be lower at all stages of exercise at 6- and 12-month follow-up in patients undergoing renal denervation , although reaching statistical significance only at mild-to-moderate exercise levels ( 75–100 W ) . At recovery after 1 minute , blood pressure decreased from 201±4/95±2 to 177±4/88±2 ( P<0.001/P=0.066 ) and 188±6/86±2 mm Hg ( P=0.059/P=0.01 ) after 6 and 12 months , respectively . Heart rate was reduced after renal denervation from 71±3 bpm at rest , 128±5 bpm at maximum workload , and 96±5 bpm at recovery after 1 minute to 66±2 ( P<0.001 ) , 115±5 ( P=0.107 ) , and 89±3 bpm ( P=0.008 ) after 6 months and to 69±3 ( P=0.092 ) , 122±7 ( P=0.01 ) , and 93±4 bpm ( P=0.032 ) after 12 months . Mean exercise time increased from 6.59±0.33 to 8.4±0.32 ( P<0.001 ) and 9.0±0.41 minutes ( P=0.008 ) , and mean workload increased from 93±2 to 100±2 ( P<0.001 ) and 101±3 W ( P=0.007 ) at 6- and 12-month follow-up , respectively . No changes were observed in the control group . In  conclusion ,  renal denervation reduced blood pressure and heart rate during exercise , improved mean workload , and increased exercise time without impairing chronotropic competence BACKGROUND The potential role of renal denervation ( RD ) in patients with AF and less severe hypertension is unknown . OBJECTIVE The purpose of this study was to assess the potential role of RD as an adjunct to pulmonary vein isolation ( PVI ) in patients with atrial fibrillation ( AF ) and moderate resistant or severe resistant hypertension . METHODS The data for this study were obtained from 2 different prospect i ve r and omized studies , analyzed by meta- analysis . Patients with paroxysmal AF or persistent AF and moderate resistant hypertension ( office blood pressure BP ≥140/90 mm Hg and < 160/100 mm Hg ; first study ; n = 48 ) or severe resistant hypertension ( ≥160/100 mm Hg ; second study ; n = 38 ) were r and omized to PVI or PVI with RD . RESULTS At 12 months , 26 of the 41 PVI with RD patients ( 63 % ) were AF-free vs 16 of the 39 patients ( 41 % ) in the PVI-only group ( P = .014 ) . In patients with severe hypertension , 11 of the 18 PVI with RD patients ( 61 % ) vs 5 of the 18 PVI-only patients ( 28 % ) were AF-free ( P = .03 ) . For moderate hypertension , the differences were less dramatic : 11 of 21 ( 52 % ) vs 15 of 23 ( 65 % ) when RD added ( P = .19 ) . The superior efficacy of adding RD was most apparent in persistent AF and severe hypertension ( hazard ratio 0.25 , confidence interval 0.09 - 0.72 , P = .01 ) . Duration of the procedure and fluoroscopy were nonsignificantly longer in the RD group . CONCLUSION RD may improve the results of PVI in patients with persistent AF and /or severe resistant hypertension & NA ; We aim ed to investigate for the first time the blood pressure (BP)–lowering effect of renal sympathetic denervation ( RDN ) versus clinical ly adjusted drug treatment in true treatment-resistant hypertension ( TRH ) after excluding patients with confounding poor drug adherence . Patients with apparent TRH ( n=65 ) were referred for RDN , and those with secondary and spurious hypertension ( n=26 ) were excluded . TRH was defined as office systolic BP ( SBP ) > 140 mm Hg , despite maximally tolerated doses of ≥3 antihypertensive drugs including a diuretic . In addition , ambulatory daytime SBP > 135 mm Hg after witnessed intake of antihypertensive drugs was required , after which 20 patients had normalized BP and were excluded . Patients with true TRH were r and omized and underwent RDN ( n=9 ) performed with Symplicity Catheter System versus clinical ly adjusted drug treatment ( n=10 ) . The study was stopped early for ethical reasons because RDN had uncertain BP-lowering effect . Office SBP and diastolic BP in the drug-adjusted group changed from 160±14/88±13 mm Hg ( ±SD ) at baseline to 132±10/77±8 mm Hg at 6 months ( P<0.0005 and P=0.02 , SBP and diastolic BP , respectively ) and in the RDN group from 156±13/91±15 to 148±7/89±8 mm Hg ( P=0.42 and P=0.48 , SBP and diastolic BP , respectively ) . SBP and diastolic BP were significantly lower in the drug-adjusted group at 6 months ( P=0.002 and P=0.004 , respectively ) , and absolute changes in SBP were larger in the drug-adjusted group ( P=0.008 ) . Ambulatory BPs changed in parallel to office BPs . Our data suggest that adjusted drug treatment has superior BP lowering effects compared with RDN in patients with true TRH . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : The first studies on renal denervation ( RDN ) suggest that this treatment is feasible , effective , and safe in the short term . Presently available data are promising , but important uncertainties exist ; therefore , SYMPATHY has been initiated . SYMPATHY is a multicenter , r and omized , controlled trial in patients r and omized to RDN in addition to usual care ( intervention group ) or to continued usual care ( control group ) . R and omization will take place in a ratio of 2 to 1 . At least 300 participants will be included to answer the primary objective . Sample size may be extended to a maximum of 570 to address key secondary objectives . The primary objective is to assess whether RDN added to usual care compared with usual care alone  reduces blood pressure ( BP ) ( ambulatory daytime systolic BP ) in subjects with an average daytime systolic BP ≥135 , despite use of ≥3 BP-lowering agents , 6 months after RDN . Key secondary objectives are evaluated at 6 months and at regular intervals during continued follow-up and include the effect of RDN on the use of BP-lowering agents , in different subgroups ( across strata of estimated glomerular filtration rate and of baseline BP ) , on office BP , quality of life , and cost-effectiveness Percutaneous renal sympathetic denervation by radiofrequency energy has been reported to reduce blood pressure ( BP ) by the reduction of renal sympathetic efferent and afferent signaling . We evaluated the effects of this procedure on BP and sleep apnea severity in patients with resistant hypertension and sleep apnea . We studied 10 patients with refractory hypertension and sleep apnea ( 7 men and 3 women ; median age : 49.5 years ) who underwent renal denervation and completed 3-month and 6-month follow-up evaluations , including  polysomnography and selected blood chemistries , and BP measurements .  Antihypertensive regimens were not changed during the 6 months of follow-up . Three and 6 months after the denervation , decreases in office systolic and diastolic BPs were observed ( median : −34/−13 mm Hg for systolic and diastolic BPs at 6 months ; both P<0.01 ) . Significant decreases were also observed in plasma glucose concentration 2 hours after glucose administration ( median : 7.0 versus 6.4 mmol/L ; P=0.05 ) and in hemoglobin A1C level ( median : 6.1 % versus 5.6 % ; P<0.05 ) at 6 months , as well as a decrease in apnea-hypopnea index at 6 months after renal denervation ( median : 16.3 versus 4.5 events per hour ; P=0.059 ) . In conclusion , catheter-based renal sympathetic denervation  lowered BP in patients with refractory hypertension and obstructive sleep apnea , which was accompanied by improvement of sleep apnea severity . Interestingly , there are also accompanying improvements in glucose tolerance . Renal sympathetic denervation may conceivably be a potentially useful option for patients with comorbid refractory hypertension , glucose intolerance , and obstructive sleep apnea , although further studies are needed to confirm these proof-of-concept data BACKGROUND Prior unblinded studies have suggested that catheter-based renal-artery denervation reduces blood pressure in patients with resistant hypertension . METHODS We design ed a prospect i ve , single-blind , r and omized , sham-controlled trial . Patients with severe resistant hypertension were r and omly assigned in a 2:1 ratio to undergo renal denervation or a sham procedure . Before r and omization , patients were receiving a stable antihypertensive regimen involving maximally tolerated doses of at least three drugs , including a diuretic . The primary efficacy end point was the change in office systolic blood pressure at 6 months ; a secondary efficacy end point was the change in mean 24-hour ambulatory systolic blood pressure . The primary safety end point was a composite of death , end-stage renal disease , embolic events result ing in end-organ damage , renovascular complications , or hypertensive crisis at 1 month or new renal-artery stenosis of more than 70 % at 6 months . RESULTS A total of 535 patients underwent r and omization . The mean ( ±SD ) change in systolic blood pressure at 6 months was -14.13±23.93 mm Hg in the denervation group as compared with -11.74±25.94 mm Hg in the sham-procedure group ( P<0.001 for both comparisons of the change from baseline ) , for a difference of -2.39 mm Hg ( 95 % confidence interval [ CI ] , -6.89 to 2.12 ; P=0.26 for superiority with a margin of 5 mm Hg ) . The change in 24-hour ambulatory systolic blood pressure was -6.75±15.11 mm Hg in the denervation group and -4.79±17.25 mm Hg in the sham-procedure group , for a difference of -1.96 mm Hg ( 95 % CI , -4.97 to 1.06 ; P=0.98 for superiority with a margin of 2 mm Hg ) . There were no significant differences in safety between the two groups . CONCLUSIONS This blinded trial did not show a significant reduction of systolic blood pressure in patients with resistant hypertension 6 months after renal-artery denervation as compared with a sham control . ( Funded by Medtronic ; SYMPLICITY HTN-3 Clinical Trials.gov number , NCT01418261 . ) Objective : Renal denervation ( RDN ) has been demonstrated to reduce muscle sympathetic nerve activity ( MSNA ) and blood pressure ( BP ) in patients with resistant hypertension . Whether alterations of arterial stiffness may contribute to BP-lowering effects of RDN is unknown . Methods : We measured office BP and arterial stiffness using fingertip tonometry-derived augmentation index ( EndoPAT2000 ) at baseline and at 3-month follow-up in 50 consecutive patients with resistant hypertension . Forty patients received RDN  and 10 patients served as controls .  MSNA was obtained in 20 RDN and 10 non-RDN patients . Results : Baseline BP averaged 170/92 ± 19/15 mmHg ( RDN ) and 171/93 ± 14/8 mmHg ( non-RDN ) despite the use of 4.9 ± 1.9 and 4.4 ± 2.0 antihypertensive drugs , respectively . RDN significantly reduced SBP ( 1 
    Output:
    
AUTHORS ' CONCLUSIONS In patients with resistant hypertension , there is low quality evidence that renal denervation does not change major cardiovascular events , and renal function .
There was moderate quality evidence that it does not change blood pressure and and low quality evidence that it caused an increaseof bradycardia episodes .