***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: OBJECTIVES This study evaluated the impact of left ventricular assist device ( LVAD ) support on survival and quality of life in inotrope-dependent heart failure patients ineligible for cardiac transplantation . BACKGROUND The role for LVADs as a bridge to cardiac transplantation has been established , but data supporting their role as permanent therapy in nontransplant c and i date s are limited . METHODS The INTrEPID ( Investigation of Nontransplant-Eligible Patients Who Are Inotrope Dependent ) trial was a prospect i ve , nonr and omized clinical trial comparing LVAD with optimal medical therapy ( OMT ) .  Fifty-five patients with New York Heart Association functional class IV symptoms who failed weaning from inotropic support were offered a Novacor LVAD .  Eighteen of these patients did not receive an LVAD owing to patient preference ( n = 14 ) or unavailability of the device ( n = 4 ) but consented to follow-up and constitute a contemporaneous control group . RESULTS The LVAD and OMT patients were well matched for demographic and disease severity measures , except OMT patients had a lower mean serum sodium ( 128 mg/dl vs. 134 mg/dl ; p = 0.001 ) and a higher mean blood urea nitrogen concentration ( 59 vs. 40 ; p = 0.02 ) . The LVAD-treated patients had superior survival rates at 6 months ( 46 % vs. 22 % ; p = 0.03 ) and 12 months ( 27 % vs. 11 % ; p = 0.02 ) . Adverse event rates were higher in the OMT group . Eighty-five percent of the LVAD-treated patients had minimal or no heart failure symptoms . Five LVAD patients and 1 OMT patient improved sufficiently while on therapy to qualify for cardiac transplantation . CONCLUSIONS Inotrope-dependent heart failure patients who are ineligible for transplantation have a high short-term mortality rate and derive a significant survival advantage from " destination " mechanical circulatory support BACKGROUND Quality of life ( QOL ) outcomes after left ventricular assist device ( LVAD ) implantation from before to after hospital discharge have been examined only in a very small sample of patients . The purpose s of this study are to describe change in QOL from before to after hospital discharge in LVAD patients and to determine whether being discharged with an LVAD predicts better QOL than being hospitalized with an LVAD . METHODS A non-r and om sample of 62 LVAD patients ( approximately 50 years old , male , white , married , fairly well-educated ) completed self-report question naires at > or=2 timepoints post-implant . The question naires ( Quality of Life Index , Rating Question Form , Heart Failure Symptom Checklist , Sickness Impact Profile , LVAD Stressor Scale , Jalowiec Coping Scale ) , which were collated into booklets , had acceptable reliability and validity . Longitudinal analyses were performed in 2 steps using 1- sample t-tests and linear mixed effects modeling . RESULTS Perception of QOL and health status were fairly good both before and after discharge of LVAD patients . Discharge predicted increased satisfaction with socioeconomic areas of life ; decreased overall and psychologic stress and stress related to family and friends , self-care and work/school/finances ; and decreased physical and self-care disability . CONCLUSIONS QOL outcomes improved from before to after hospital discharge in LVAD patients awaiting heart transplantation . As LVADs potentially become available as destination therapy , in addition to being successful bridges to heart transplantation , QOL outcomes will become more important to study OBJECTIVES The purpose of this study was to determine the occurrence and causes of readmissions  after implantation of axial flow left ventricular assist device ( LVAD ) .  BACKGROUND Based on the REMATCH ( R and omized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure ) study experience , readmissions after LVAD implantation  are thought to be frequent . METHODS We retrospectively analyzed admissions to our facility in a cohort of 115 patients implanted between January 2008 and July 2011 with the HeartMate II axial flow LVAD , of whom 42 were bridged to transplant . To account for repeated events , And ersen-Gill models were used to determine possible predictors . RESULTS The patients were followed for 1.4 ± 0.9 years . There were 224 readmissions in 83 patients . The overall readmission rate was 1.64 ± 1.97 per patient-year of follow-up . The readmission rate for the first 6 months was 2.0 ± 2.3 and decreased to 1.2 ± 2.1 during subsequent follow-up . Leading causes were bleeding ( 66 readmissions in 34 patients ) , mostly gastrointestinal bleed ( 51 in 27 patients ) , cardiac ( 51 in 36 patients , most for HF or arrhythmia ) , infections ( 32 in 25 patients ) of which 6 were pump related , and thrombosis ( 20 in 15 patients ) including 13 readmissions due to hemolysis . Preoperative variables associated with ( fewer ) readmissions in a multivariate model include residence within our hospital-extended referral zone of Minnesota and the neighboring states ( hazard ratio : 0.66 ; 95 % confidence interval : 0.48 to 0.91 ; p = 0.011 ) , hemoglobin ( hazard ratio : 0.91 , 95 % confidence interval : 0.84 to 0.99 ; p = 0.027 ) and N-terminal pro-B-type natriuretic peptide ( hazard ratio : 0.98 ; 95 % confidence interval : 0.96 to 1.0 per 1,000-unit increase , p = 0.022 ) . C-statistic for the model : 0.63 . CONCLUSIONS Readmission rates  after axial flow LVAD implantation decrease during the first 6 months and then stabilize . The leading causes are bleeding , cardiac ( heart failure and arrhythmia ) , infections , and thrombosis BACKGROUND The number of patients undergoing implantation of a HeartMate II left ventricular assist device ( LVAD ;  Thoratec Corporation , Pleasanton , Calif ) is rising . Ventricular tachyarrhythmia ( VA ) after placement of the device is common , especially among patients with preoperative VA . We sought to determine whether intraoperative cryoablation in select patients reduces the incidence of postoperative VA . METHODS From January 2009 through September 2010 , 50 consecutive patients undergoing implantation of the HeartMate II LVAD were examined . Fourteen of these patients had recurrent preoperative VA . Of those patients with recurrent VA , half underwent intraoperative cryoablation ( Cryo : n = 7 ) and half did not ( NoCryo : n = 7 ) . Intraoperatively , patients underwent localized epicardial and endocardial cryoablation via LVAD ventriculotomy . Cryothermal lesions were created to connect scar to fixed anatomic borders in the region of clinical VA . Demographics , risk factors , intraoperative features , and outcomes were analyzed to investigate the feasibility of cryoablation . RESULTS Thirty-day mortality remained low ( n = 1 , 2 % ) among all LVAD recipients . There were no differences in risk factors between groups except that preoperative inotropes were less prevalent in Cryo patients ( P = .09 ) . Compared with NoCryo , the Cryo group had significantly decreased postoperative re source use and complications ( P < .05 ) . Recurrent postoperative VA did not develop in any of the Cryo patients ( P = .02 ) . CONCLUSIONS Postoperative VA can be minimized by preoperative risk assessment and intraoperative treatment . Localized cryoablation in select patients offers promising early feasibility when performed during HeartMate II LVAD implantation . Further prospect i ve analysis is required to investigate this novel approach BACKGROUND Implantable left ventricular assist devices have benefited patients with end-stage heart failure as a bridge to cardiac transplantation , but their long-term use for the purpose of enhancing survival and the quality of life has not been evaluated . METHODS We r and omly assigned 129 patients with end-stage heart failure who were ineligible for cardiac transplantation to receive a left ventricular assist device ( 68 patients ) or optimal medical management ( 61 ) . All patients had symptoms of New York Heart Association class IV heart failure . RESULTS Kaplan-Meier survival analysis showed a reduction of 48 percent in the risk of death from any cause in the group that received left ventricular assist devices as compared with the medical-therapy group ( relative risk , 0.52 ; 95 percent confidence interval , 0.34 to 0.78 ; P=0.001 ) . The rates of survival at one year were 52 percent in the device group and 25 percent in the medical-therapy group ( P=0.002 ) , and the rates at two years were 23 percent and 8 percent ( P=0.09 ) , respectively . The frequency of serious adverse events in the device group was 2.35 ( 95 percent confidence interval , 1.86 to 2.95 ) times that in the medical-therapy group , with a predominance of infection , bleeding , and malfunction of the device . The quality of life was significantly improved at one year in the device group . CONCLUSIONS The use of a left ventricular assist device in patients with advanced heart failure result ed in a clinical ly meaningful survival benefit and an improved quality of life . A left ventricular assist device is an acceptable alternative therapy in selected patients who are not c and i date s for cardiac transplantation OBJECTIVES This study sought to evaluate the use of a continuous-flow rotary left ventricular assist device ( LVAD ) as a bridge to heart transplantation . BACKGROUND LVAD therapy is an established treatment modality for patients with advanced heart failure . Pulsatile LVADs have limitations in design precluding their use for extended support . Continuous-flow rotary LVADs represent an innovative design with potential for small size and greater reliability by simplification of the pumping mechanism . METHODS In a prospect i ve , multicenter study , 281 patients urgently listed ( United Network of Organ Sharing status 1A or 1B ) for heart transplantation underwent implantation of a continuous-flow LVAD .  Survival and transplantation rates were assessed at 18 months . Patients were assessed for adverse events throughout the study and for quality of life , functional status , and organ function for 6 months . RESULTS Of 281 patients , 222 ( 79 % ) underwent transplantation , LVAD removal for cardiac recovery , or had ongoing LVAD support at 18-month follow-up . Actuarial survival on support was 72 % ( 95 % confidence interval : 65 % to 79 % ) at 18 months . At 6 months , there were significant improvements in functional status and 6-min walk test ( from 0 % to 83 % of patients in New York Heart Association functional class I or II and from 13 % to 89 % of patients completing a 6-min walk test ) and in quality of life ( mean values improved 41 % with Minnesota Living With Heart Failure and 75 % with Kansas City Cardiomyopathy question naires ) . Major adverse events included bleeding , stroke , right heart failure , and percutaneous lead infection . Pump thrombosis occurred in 4 patients . CONCLUSIONS A continuous-flow LVAD provides effective hemodynamic support for at least 18 months in patients awaiting transplantation , with improved functional status and quality of life . ( Thoratec HeartMate II Left Ventricular Assist System [ LVAS ] for Bridge to Cardiac Transplantation ; NCT00121472 ) BACKGROUND Patients with advanced heart failure have improved survival rates and quality of life when treated with implanted pulsatile-flow left ventricular assist devices as compared with medical therapy . New continuous-flow devices are smaller and may be more durable than the pulsatile-flow devices . METHODS In this r and omized trial , we enrolled patients with advanced heart failure who were ineligible for transplantation , in a 2:1 ratio , to undergo implantation of a continuous-flow device ( 134 patients ) or the currently approved pulsatile-flow device ( 66 patients ) . The primary composite end point was , at 2 years , survival free from disabling stroke and reoperation to repair or replace the device . Secondary end points included survival , frequency of adverse events , the quality of life , and functional capacity . RESULTS Preoperative characteristics were similar in the two treatment groups , with a median age of 64 years ( range , 26 to 81 ) , a mean left ventricular ejection fraction of 17 % , and nearly 80 % of patients receiving intravenous inotropic agents . The primary composite end point was achieved in more patients with continuous-flow devices than with pulsatile-flow devices ( 62 of 134 [ 46 % ] vs. 7 of 66 [ 11 % ] ; P<0.001 ; hazard ratio , 0.38 ; 95 % confidence interval , 0.27 to 0.54 ; P<0.001 ) , and patients with continuous-flow devices had superior actuarial survival rates at 2 years ( 58 % vs. 24 % , P=0.008 ) . Adverse events and device replacements were less frequent in patients with the continuous-flow device . The quality of life and functional capacity improved significantly in both groups . CONCLUSIONS Treatment with a continuous-flow left ventricular assist device in patients with advanced heart failure significantly improved the probability of 
    Output:
    
Improvements in functional class and quality of life were reported , but missing data complicated interpretation .
Adverse events were experienced by the majority of patients , but estimates for bleeding , stroke , infection , right heart failure , arrhythmias , and rehospitalizations varied greatly .
The totality of data for continuous-flow left ventricular assist devices show consistent improvements in survival and quality of life counterbalanced by a range of common complications .