***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Sleep apnea is common in hospitalized heart failure ( HF ) patients and is associated with increased morbidity and mortality . OBJECTIVES The CAT-HF ( Cardiovascular Improvements With MV-ASV Therapy in Heart Failure ) trial investigated whether minute ventilation ( MV ) adaptive servo-ventilation ( ASV ) improved cardiovascular outcomes in hospitalized HF patients with moderate-to-severe sleep apnea . METHODS Eligible patients hospitalized with HF and moderate-to-severe sleep apnea were r and omized to ASV plus optimized medical therapy ( OMT ) or OMT alone ( control ) . The primary endpoint was a composite global rank score ( hierarchy of death , cardiovascular hospitalizations , and percent changes in 6-min walk distance ) at 6 months . RESULTS 126 of 215 planned patients were r and omized ; enrollment was stopped early following release of the SERVE-HF ( Adaptive Servo-Ventilation for Central Sleep Apnea in Systolic Heart Failure ) trial results . Average device usage was 2.7 h/night . Mean number of events measured by the apnea-hypopnea index decreased from 35.7/h to 2.1/h at 6 months in the ASV group versus 35.1/h to 19.0/h in the control group ( p < 0.0001 ) . The primary endpoint did not differ significantly between the ASV and control groups ( p = 0.92 Wilcoxon ) . Changes in composite endpoint components were not significantly different between ASV and control . There was no significant interaction between treatment and ejection fraction ( p = 0.10 Cox model ) ; however , pre-specified subgroup analysis suggested a positive effect of ASV in patients with HF with preserved ejection fraction ( p = 0.036 ) . CONCLUSIONS In hospitalized HF patients with moderate-to-severe sleep apnea , adding ASV to OMT did not improve 6-month cardiovascular outcomes . Study power was limited for detection of safety signals and identifying differential effects of ASV in patients with HF with preserved ejection fraction , but additional studies are warranted in this population . ( Cardiovascular Improvements With MV ASV Therapy in Heart Failure [ CAT-HF ] ; NCT01953874 ) Background — In the main analysis of the Canadian Continuous Positive Airway Pressure ( CPAP ) for Patients with Central Sleep Apnea ( CSA ) and Heart Failure Trial ( CANPAP ) , CPAP had no effect on heart transplant – free survival ; however , CPAP only reduced the mean apnea-hypopnea index to 19 events per hour of sleep , which remained above the trial inclusion threshold of 15 . This stratified analysis of CANPAP tested the hypothesis that suppression of CSA below this threshold by CPAP would improve left ventricular ejection fraction and heart transplant – free survival . Methods and Results — Of the 258 heart failure patients with CSA in CANPAP  , 110 of the 130 r and omized to the control group and 100 of the 128 r and omized to CPAP had sleep studies 3 months later . CPAP patients were divided post hoc into those whose  apnea-hypopnea index was or was not reduced below 15 at this time ( CPAP-CSA suppressed , n=57 , and CPAP-CSA unsuppressed , n=43 , respectively ) . Their changes in left ventricular ejection fraction and heart transplant – free survival were compared with those in the control group . Despite similar CPAP pressure and hours of use in the 2 groups , CPAP-CSA – suppressed subjects experienced a greater increase in left ventricular ejection fraction at 3 months ( P=0.001 ) and significantly better transplant-free survival ( hazard ratio [ 95 % confidence interval ] 0.371 [ 0.142 to 0.967 ] , P=0.043 ) than control subjects , whereas the CPAP-CSA – unsuppressed group did not ( for left ventricular ejection fraction , P=0.984 , and for transplant-free survival , hazard ratio 1.463 [ 95 % confidence interval 0.751 to 2.850 ] , P=0.260 ) . Conclusions — These results suggest that in heart failure patients , CPAP might improve both left ventricular ejection fraction and heart transplant – free survival if CSA is suppressed soon after its initiation BACKGROUND Continuous positive airway pressure ( CPAP ) improves cardiac function in patients with congestive heart failure ( CHF ) who also have Cheyne-Stokes respiration and central sleep apnea ( CSR-CSA ) . However , the effects of CPAP in CHF patients without CSR-CSA have not been tested , and the long-term effects of this treatment on clinical cardiovascular outcomes are unknown . METHODS AND RESULTS We conducted a r and omized , controlled trial in which 66 patients with CHF ( 29 with and 37 without CSR-CSA ) were r and omized to either a group that received CPAP nightly or to a control group . Change in left ventricular ejection fraction ( LVEF ) from baseline to 3 months and the combined mortality-cardiac transplantation rate over the median 2.2-year follow-up period were compared between the CPAP-treated and control groups . For the entire group of patients , CPAP had no significant effect on LVEF , but it was associated with a 60 % relative risk reduction ( 95 % confidence interval , 2 % to 64 % ) in mortality-cardiac transplantation rate in patients who complied with CPAP therapy . Stratified analysis of patients with and without CSR-CSA revealed that those with CSR-CSA experienced both a significant improvement in LVEF at 3 months and a relative risk reduction of 81 % ( 95 % confidence interval , 26 % to 95 % ) in the mortality-cardiac transplantation rate of those who used CPAP . CPAP had no significant effect on either of these outcomes in patients without CSR-CSA . CONCLUSIONS CPAP improves cardiac function in CHF patients with CSR-CSA but not in those without it . Although not definitive , our findings also suggest that CPAP can reduce the combined mortality-cardiac transplantation rate in those CHF patients with CSR-CSA who comply with therapy Background —In patients with chronic heart failure ( CHF ) , the presence of sleep-disordered breathing , including either obstructive sleep apnea or Cheyne-Stokes respiration- central sleep apnea , is associated with a poor prognosis . A large-scale clinical trial showed that continuous positive airway pressure ( CPAP ) did not improve the prognosis of such patients with CHF , probably because of insufficient sleep-disordered breathing suppression . Recently , it was reported that adaptive servo-ventilation ( ASV ) can effectively treat sleep-disordered breathing . However , there are no specific data about the efficacy of flow-triggered ASV for cardiac function in patients with CHF with sleep-disordered breathing . The aim of this study was to compare the efficacy of flow-triggered ASV to CPAP in patients with CHF with coexisting obstructive sleep apnea and Cheyne-Stokes respiration- central sleep apnea . Methods and Results —Thirty-one patients with CHF , defined as left ventricular ejection fraction < 50 % and New York Heart Association class ≥II , with coexisting obstructive sleep apnea and Cheyne-Stokes respiration- central sleep apnea , were r and omly assigned to either CPAP or flow-triggered ASV . The suppression of respiratory events , changes in cardiac function , and compliance with the devices during the 3-month study period were compared . Although both devices decreased respiratory events , ASV more effectively suppressed respiratory events ( & Dgr;AHI [ apnea-hypopnea index ] , −35.4±19.5 with ASV ; −23.2±12.0 with CPAP , P<0.05 ) . Compliance was significantly greater with ASV than with CPAP ( 5.2±0.9 versus 4.4±1.1 h/night , P<0.05 ) . The improvements in quality -of-life and left ventricular ejection fraction were greater in the ASV group ( & Dgr;LVEF [ left ventricular ejection fraction ] , + 9.1±4.7 % versus + 1.9±10.9 % ) . Conclusions —These results suggest that patients with coexisting obstructive sleep apnea and Cheyne-Stokes respiration- central sleep apnea may receive greater benefit from treatment with ASV than with CPAP AIMS The SERVE-HF trial investigated the impact of treating central sleep apnoea ( CSA ) with adaptive servo-ventilation ( ASV ) in patients with systolic heart failure . A preplanned sub study was conducted to provide insight into mechanistic changes underlying the observed effects of ASV , including assessment of changes in left ventricular function , ventricular remodelling , and cardiac , renal and inflammatory biomarkers . METHODS AND RESULTS In a subset of the 1325 r and omised patients , echocardiography , cardiac magnetic resonance imaging ( cMRI ) and biomarker analysis were performed at baseline , and 3 and 12 months . In secondary analyses , data for patients with baseline and 12-month values were evaluated ; 312 patients participated in the sub study . The primary endpoint , change in echocardiographically determined left ventricular ejection fraction from baseline to 12 months , did not differ significantly between the ASV and the control groups . There were also no significant between-group differences for changes in left ventricular dimensions , wall thickness , diastolic function or right ventricular dimensions and ejection fraction ( echocardiography ) , and on cMRI ( in small patient numbers ) . Plasma N-terminal pro B-type natriuretic peptide concentration decreased in both groups , and values were similar at 12 months . There were no significant between-group differences in changes in cardiac , renal and systemic inflammation biomarkers . CONCLUSION In patients with systolic heart failure and CSA , addition of ASV to guideline -based medical management had no statistically significant effect on cardiac structure and function , or on cardiac biomarkers , renal function and systemic inflammation over 12 months . The increased cardiovascular mortality reported in SERVE-HF may not be related to adverse remodelling or worsening heart failure Background : Cheyne-Stokes respiration frequently occurs in patients with congestive heart failure ( CHF ) .  Adaptive servoventilation ( ASV ) is a novel therapy with potential benefits . This prospect i ve r and omized trial investigated the effects of ASV on myocardial function and physical capacity . Methods : Patients with severe CHF , despite optimal cardiac medication and /or left ventricular ejection fraction ( LVEF ) ≤40 % and Cheyne-Stokes breathing for > 25 % of sleeping time were included . Fifty-one patients , age 57 - 81 years ( 4 were women ) , were r and omized to either an ASV or a control group ; 30 patients completed the study ( 15 from each group ) . The primary end point was any change in LVEF . The secondary end points were alterations in physical capacity according to the 6-min walk test or the New York Heart Association ( NYHA ) class . Results : In the ASV-treatment  group , LVEF improved from baseline ( 32 ± 11 % ) to study end ( 36 ± 13 % ) , p = 0.013 . The 6-min walk test improved from 377 ± 115 to 430 ± 123 m ( p = 0.014 ) and the NYHA class from 3.2 ( 3.0 - 3.0 ) to 2.0 ( 2.0 - 3.0 ) ( p < 0.001 ) . No changes occurred in the control group . Conclusion : Three months of ASV  treatment improved LVEF and physical capacity in CHF patients with Cheyne-Stokes respiration . These results suggest that ASV may be a beneficial supplement to st and ard medication in these patients Objective : To compare compliance with and effectiveness of adaptive servoventilation ( ASV ) versus continuous positive airway pressure ( CPAP ) in patients with the central sleep apnoea syndrome ( CSA ) with Cheyne-Stokes respiration ( CSR ) and with congestive heart failure in terms of the apnoea – hypopnoea index ( AHI ) , quality of life , and left ventricular ejection fraction ( LVEF ) over six months . Methods : 25 patients ( age 28–80 years , New York Heart Association ( NYHA ) class II – IV ) with stable congestive heart failure and CSA-CSR were r and omly assigned to either CPAP or ASV . At inclusion , both groups were comparable for NYHA class , LVEF , medical treatment , body mass index , and CSA-CSR . Results : Both ASV and CPAP  decreased the AHI but , noticeably , only ASV  completely corrected CSA-CSR , with AHI below 10/h . At three months , compliance was comparable between ASV and CPAP ; however , at six months compliance with CPAP was significantly less than with ASV . At six months , the improvement in quality of life was higher with ASV and only ASV induced a significant increase in LVEF . Conclusion : These results suggest that patients with CSA-CSR may receive greater benefit from treatment with ASV than with CPAP We tested the hypotheses that in patients with congestive heart failure ( CHF ) and sleep disordered breathing ( SDB )  auto-servoventilation ( ASV ) improves cardiac function and quality of life . Between March 2007 and September 2009 , patients with stable CHF ( left ventricular ejection fraction ( LVEF ) ≤40 % ) and SDB ( apnoea/hypopnoea index ≥20 events·h−1 ) were r and omised to receive either ASV ( BiPAP ASV ( Philips Respironics , Murrysville , PA , USA ) , n= 
    Output:
    
ASV did not significantly decrease the E/e′ ratio in RCTs or in cohorts .
ASV did not have a significant effect on systolic blood pressure , diastolic blood pressure , and cardiac diameters .
ASV therapy is associated with improvements of AHI in comparison to alternative treatments in patients with SDB and HF .
ASV did not improve LVEF or E/e′ ratios in r and omized trials ; other intermediate outcomes did not improve significantly