***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 — Chronic obstructive pulmonary disease ( COPD ) is associated with increased in-hospital mortality in patients undergoing coronary artery bypass surgery ( CABG ) .  Long-term survival is less well understood . The present study examined the effect of COPD on survival after CABG . Methods and Results — We conducted a prospect i ve study of 33 137 consecutive isolated CABG patients between 1992 and 2001 in northern New Engl and . Records were linked to the National Death Index for long-term mortality data . Cox proportional hazards regression was used to calculate hazard ratios ( HRs ) . Patients were stratified by : no comorbidities ( none ) , COPD , COPD plus comorbidities , and other comorbidities with no COPD . There were 131 434 person years of follow-up and 5344 deaths . The overall incidence rate ( deaths per 100 person years ) was 4.1 . By group , rates were : 2.1 ( none ) , 4.0 ( COPD alone ) , 5.5 ( other ) , and 9.4 ( COPD plus ; log rank P<0.001 ) . After adjustment , survival with COPD alone was worse compared with none ( HR , 1.8 ; 95 % CI , 1.6 to 2.1 ; P<0.001 ) . Patients with other comorbidities compared with none had even worse survival ( HR , 2.2 ; 95 % CI , 2.1 to 2.4 ; P<0.001 ) . Patients with COPD plus other comorbidities compared with none had the worst long-term survival ( HR , 3.6 ; 95 % CI , 3.3 to 3.9 ; P<0.001 ) . Conclusions — Patients with only COPD had significantly reduced long-term survival compared with patient with no comorbidities . Patients with COPD and ≥1 other comorbidity had the worst survival rate when compared with all of the other groups Background —The introduction of limited approaches to the heart and the avoidance of cardiopulmonary bypass ( CPB ) aim to reduce the invasiveness of CABG by decreasing the systemic release of inflammatory cytokines , such as tumor necrosis factor (TNF)-&agr ; , interleukin (IL)-6 , and IL-8 , as well as the anti-inflammatory agent IL-10 . This study compares the humoral immune response in patients undergoing CABG with st and ard , minimally invasive , and “ off-pump ” techniques . Methods and Results —Thirty patients were divided into 3 operative groups : full sternotomy approach plus CPB ( group A ) ; full sternotomy approach , off pump ( group B ) ; and limited left anterior thoracotomy , off pump ( group C ) . Plasma levels of TNF-&agr ; receptors p55 and p75 , IL 6 , IL-8 , and IL-10 were taken at baseline , during CPB , and at 4 , 24 , and 48 hours and 6 days after surgery . A significant increased release of activated complement factors C5a and C3d , IL-8 , and IL-10 was observed in patients subjected to CPB ( group A ) during the initial period and for a short time after perfusion ( P < 0.05 ) . TNF-&agr ; receptors p55 and p75 showed a prolonged elevation ( up to 48 hours ) in the CPB group compared with the 2 off-pump groups . IL-6 showed no different release among the 3 surgical groups throughout the entire period . There was no significant difference in any parameter measured in relation to the type of operative approach . Conclusions —There is an inflammatory , as well as an anti-inflammatory , response during CABG that is related to the general surgical trauma . The release of immune mediators is enhanced by the use of CPB during various perioperative and postoperative phases . The type of operative approach did not influence this immune response Introduction Absence of pulmonary perfusion during cardiopulmonary bypass ( CPB ) may be associated with reduced postoperative oxygenation . Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease ( COPD ) undergoing cardiac surgery . Methods 90 patients were r and omised to receive pulmonary artery perfusion during CPB with either oxygenated blood ( n=30 ) or histidine-tryptophan-ketoglutarate ( HTK ) solution ( n=29 ) compared with no pulmonary perfusion ( n=31 ) . The co primary outcomes were the inverse oxygenation index compared at 21 hours after starting CPB and longitudinally in a mixed-effects model ( MEM ) . Secondary outcomes were tracheal intubation time , serious adverse events , mortality , days alive outside the intensive care unit ( ICU ) and outside the hospital . Results 21 hours after starting CPB patients receiving pulmonary artery perfusion with normothermic oxygenated blood had a higher oxygenation index compared with no pulmonary perfusion ( mean difference ( MD ) 0.94 ; 95 % CI 0.05 to 1.83 ; p=0.04 ) . The blood group had also a higher oxygenation index both longitudinally ( MEM , p=0.009 ) and at 21 hours ( MD 0.99 ; CI 0.29 to 1.69 ; p=0.007 ) compared with the HTK group . The latest result corresponds to a difference in the arterial partial pressure of oxygen of 23 mm Hg with a median fraction of inspired oxygen of 0.32 . Yet the blood or HTK groups did not demonstrate a longitudinally higher oxygenation index compared with no pulmonary perfusion ( MEM , p=0.57 and 0.17 ) . Similarly , at 21 hours there was no difference in the oxygenation index between the HTK group and those no pulmonary perfusion ( MD 0.06 ; 95 % CI −0.73 to 0.86 ; p=0.87 ) . There were no statistical significant differences between the groups for the secondary outcomes . Discussion Pulmonary artery perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery .  Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation . Trial registration number NCT01614951 ; Pre- results Background Pulmonary dysfunction complicates cardiac surgery that includes cardiopulmonary bypass . The pulmonary protection trial evaluates effect of pulmonary perfusion on pulmonary function in patients suffering from chronic obstructive pulmonary disease . This paper presents the statistical plan for the main publication to avoid risk of outcome reporting bias , selective reporting , and data -driven results as an up date to the published design and method for the trial . Results The pulmonary protection trial is a r and omized , parallel group clinical trial that assesses the effect of pulmonary perfusion with oxygenated blood or Custodiol ™ HTK ( histidine-tryptophan-ketoglutarate ) solution versus no pulmonary perfusion in 90 chronic obstructive pulmonary disease patients . Patients , the statistician , and the conclusion drawers are blinded to intervention allocation . The primary outcome is the oxygenation index from 10 to 15 minutes after the end of cardiopulmonary bypass until 24 hours thereafter . Secondary outcome measures are oral tracheal intubation time , days alive outside the intensive care unit , days alive outside the hospital , and 30- and 90-day mortality , and one or more of the following selected serious adverse events : pneumothorax or pleural effusion requiring drainage , major bleeding , reoperation , severe infection , cerebral event , hyperkaliemia , acute myocardial infa rct ion , cardiac arrhythmia , renal replacement therapy , and readmission for a respiratory-related problem . Conclusions The pulmonary protection trial investigates the effect of pulmonary perfusion during cardiopulmonary bypass in chronic obstructive pulmonary disease patients . A preserved oxygenation index following pulmonary perfusion may indicate an effect and inspire to a multicenter confirmatory trial to assess a more clinical ly relevant outcome .Trial registration Clinical Trials.gov identifier : NCT01614951 , registered on 6 June Aims The association between lung function and cardiac markers and heart failure ( HF ) has been little studied in the general older population . We have examined the association between lung function and airway obstruction with cardiac markers N-terminal pro-brain natriuretic peptide ( NT-proBNP ) and cardiac troponin T ( cTnT ) and risk of incident HF in older men . Methods and results Prospect i ve study of 3242 men aged 60–79 years without prevalent HF or myocardial infa rct ion followed up for an average period of 13 years , in whom 211 incident HF cases occurred .  Incident HF was examined in relation to % predicted FEV1 and FVC . The Global Initiative on Obstructive Lung Diseases spirometry criteria were used to define airway obstruction . Reduced FEV1 , but not FVC in the normal range , was significantly associated with increased risk of HF after adjustment for established HF risk factors including inflammation . The adjusted HRs comparing men in the 6–24th percentile with the highest quartile were 1.91 ( 1.24 to 2.94 ) and 1.30 ( 0.86 to 1.96 ) for FEV1 and FVC , respectively . FEV1 and FVC were inversely associated with NT-proBNP and cTnT , although the association between FEV1 and incident HF remained after adjustment for NT-proBNP and cTnT. Compared with normal subjects ( FEV1/FVC ≥0.70 and FVC≥80 % ) , moderate or severe ( FEV1/FVC < 0.70 and FEV1 < 80 % ) airflow obstruction was independently associated with HF ( ( adjusted relative risk 1.59 ( 1.08 to 2.33 ) ) . Airflow restriction ( FEV1/FVC ≥0.70 and FVC < 80 % ) was not independently associated with HF . Conclusions Reduced FEV1 reflecting airflow obstruction is associated with cardiac dysfunction and increased risk of incident HF in older men The objective of this research was to demonstrate a framework for drawing inference from sensitivity analyses of incomplete longitudinal clinical trial data via a re- analysis of data from a confirmatory clinical trial in depression . A likelihood-based approach that assumed missing at r and om ( MAR ) was the primary analysis . Robustness to departure from MAR was assessed by comparing the primary result to those from a series of analyses that employed varying missing not at r and om ( MNAR ) assumptions ( selection models , pattern mixture models and shared parameter models ) and to MAR methods that used inclusive models . The key sensitivity analysis used multiple imputation assuming that after dropout the trajectory of drug-treated patients was that of  placebo treated patients with a similar outcome history  ( placebo multiple imputation ) . This result was used as the worst reasonable case to define the lower limit of plausible values for the treatment contrast . The endpoint contrast from the primary analysis was - 2.79 ( p = .013 ) . In placebo multiple imputation , the result was - 2.17 . Results from the other sensitivity analyses ranged from - 2.21 to - 3.87 and were symmetrically distributed around the primary result . Hence , no clear evidence of bias from missing not at r and om data was found . In the worst reasonable case scenario , the treatment effect was 80 % of the magnitude of the primary result . Therefore , it was concluded that a treatment effect existed . The structured sensitivity framework of using a worst reasonable case result based on a controlled imputation approach with transparent and debatable assumptions supplemented a series of plausible alternative models under varying assumptions was useful in this specific situation and holds promise as a generally useful framework Background R and omized controlled trials ( RCTs ) that use the modified intention-to-treat ( mITT ) approach are increasingly being published . Such trials have a preponderance of post-r and omization exclusions , industry sponsorship , and favourable findings , and little is known whether in terms of these items mITT trials are different with respect to trials that report a st and ard intention-to-treat . Methods To determine differences in the method ological quality , sponsorship , authors ' conflicts of interest , and findings among trials with different " types " of intention-to-treat , we undertook a cross-sectional study of RCTs published in 2006 in three general medical journals ( the Journal of the American Medical Association , the New Engl and Journal of Medicine and the Lancet ) and three specialty journals ( Antimicrobial Agents and Chemotherapy , the American Heart Journal and the Journal of Clinical Oncology ) . Trials were categorized based on the " type " of intention-to-treat reporting as follows : ITT , trials reporting the use of st and ard ITT approach ; mITT , trials reporting the use of a " modified intention-to-treat " approach ; and " no ITT "  , trials  not reporting the use of any intention-to-treat approach . Two pairs of review ers independently extracted the data in duplicate . The strength of the associations between the " type " of intention-to-treat reporting and the quality of reporting ( sample size calculation , flow-chart , lost to follow-up ) , the method ological quality of the trials ( sequence generation , allocation concealment , and blinding ) , the funding source , and the findings was determined . Odds ratios ( OR ) were calculated with 95 % confidence intervals ( CI ) . Results Of the 367 RCTs included , 197 were classified as ITT , 56 as mITT , and 114 as " no ITT " trials . The quality of reporting and the method ological quality of the mITT trials were similar to those of the 
    Output:
    
TSA on intubation time showed that the boundary for lack of superiority ( futility ) was crossed refuting a shorten intubation time of 1.5 hours or more .
Our trial provided additional knowledge about the use of pulmonary artery perfusion during CPB in cardiac surgery patients with COPD , and improved oxygenation for patients receiving pulmonary artery perfusion with oxygenated blood .
Pulmonary artery perfusion with HTK solution did not result in an improved oxygenation .
In line with this , the systematic review including data from additional trials showed a possible association between pulmonary artery perfusion with blood and improved oxygenation , but no significant associations with mortality , serious adverse events or intubation time .