***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 Co-morbid conditions including risk factors for cardiovascular diseases and left ventricular dysfunction are common in patients with chronic obstructive pulmonary disease ( COPD ) . This study assessed the incidence of cardiac troponin I ( cTnI ) elevation , a specific marker for cardiac injury , and its prognostic significance during severe exacerbation of COPD . Design Prospect i ve cohort study . Setting Two intensive care units . Participants Seventy-one consecutive patients admitted for severe exacerbation of COPD .InterventionNone  . Measurements and results  Cardiac troponin I  was assayed in blood sample s obtained on admission and 24 h later ( Stratus II immunoassay analyser , Dade International ) . Levels above 0.5 ng/ml were considered positive . The following data were recorded prospect ively : clinical symptoms , co-morbidities , cause of the exacerbation , diagnostic procedures and treatment , general severity score ( SAPS II ) and in-hospital outcome . CTnI was positive in 18 % of patients ( 95 % confidence interval ( CI95 ) , 11–29 % ) , with a median value at 1.00 ng/ml ; CI95 ( 0.60–1.70 ) . Eighteen patients died in the hospital ( 25 % ; CI95 , 17–37 % ) . Only cTnI ( adjusted odds ratio ( ORa ) , 6.52 ; CI95,1.23–34.47 ) and SAPS II 24 h after admission ( ORa , 1.07 ; CI95 , 1.01–1.13 ) were independent predictors of in-hospital mortality . Conclusion Elevated cTnI is a strong and independent predictor of in-hospital death in patients admitted for acutely exacerbated COPD Objective To assess the prevalence and long-term prognostic value of a dynamic ( rise/fall ) pattern of cardiac troponin T ( hs-cTnT ) elevation during acute exacerbation of chronic obstructive pulmonary disease ( AE COPD ) compared with a stable hs-cTnT elevation . Methods Prospect i ve cohort study of unselected patients admitted with AE COPD to the emergency room of a university hospital .  Serial hs-cTnT measurements were made during admission . Survival after a median of 1.8 years was recorded . Results 83 patients with a mean age of 72 years and a mean forced expiratory volume in 1 s ( FEV1 ) of 0.9 L. The mortality rate was 62 % . The median hs-cTnT at admission was 27 ng/L ( IQR 13.4–51 ) ) . 65 patients ( 78 % ) had at least one hs-cTnT measurement ≥14 ng/L , and among these the median change in hs-cTnT was 50.7 % ( IQR 25.2–89.4 ) . Of the patients with serial hs-cTnT measurements , 53 ( 82 % ) had a dynamic pattern ( ie , ΔTnT ≥20 % ) . In multivariate analysis , stable hs-cTnT elevation was associated with increasing age ( OR per 5 years with 95 % CI 1.9 ( 1.01 to 3.7 ) , p=0.045 ) and low Hb ( OR 7.3 ( 1.1 to 49 ) , p=0.039 ) . Stable hs-cTnT elevation was associated with increased mortality with an HR of 2.4 ( 95%CI 1.1 to 5.3 , p=0.027 ) in the multivariate Cox regression analysis . Conclusions Among the patients with at least one hs-cTnT above the 99th centile , 82 % had a rise/fall pattern , as requested to make a diagnosis of myocardial infa rct ion . Compared to a dynamic rise/fall pattern of hs-cTnT , a stable and moderately elevated hs-cTnT during AE COPD is associated with poor long-term prognosis Background Cardiovascular disease is prevalent and frequently unrecognized in patients with chronic obstructive pulmonary disease ( COPD ) . NT-proBNP is an established risk factor in patients with heart failure . NT-proBNP may also be released from the right ventricle . Thus serum NT-proBNP may be elevated during acute exacerbations of COPD ( AE COPD ) . The prognostic value of NT-proBNP in patients hospitalized with AE COPD is sparsely studied . Our objective was to test the hypothesis that NT-proBNP independently predicts long term mortality following AE COPD . Methods A prospect i ve cohort study of 99 patients with 217 admissions with AE COPD .  Clinical , electrocardiographic , radiological and biochemical data were collected at index and repeat admissions and analyzed in an extended survival analysis with time-dependent covariables . Results Median follow-up time was 1.9 years , and 57 patients died during follow-up . NT-proBNP tertile limits were 264.4 and 909 pg/mL , and NT-proBNP in tertiles 1 through 3 was associated with mortality rates of 8.6 , 35 and 62 per 100 patient-years , respectively ( age-adjusted log-rank p<0.0001 ) . After adjustment for age , gender , peripheral edema , cephalization and cTnT in a multivariable survival model , the corresponding hazard ratios for dying were 2.4 ( 0.95 - 6.0 ) and 3.2 ( 1.3 - 8.1 ) ( with 95 % confidence intervals in parentheses , p-value for trend 0.013 ) . Conclusions NT-proBNP is a strong and independent determinant of mortality after AE COPD Background Retrospective studies suggest that plasma levels of N-terminal pro-brain natriuretic peptide ( NT-proBNP ) and cardiac troponin T are often elevated in patients with acute exacerbations of chronic obstructive pulmonary disease ( COPD ) and are associated with increased mortality . These cardiac biomarkers were investigated in an unselected cohort of patients admitted to hospital with exacerbations of COPD . Methods Consecutive patients with physician-diagnosed COPD exacerbation but without clinical evidence of acute cardiac disease admitted to a public hospital over a 1 year period were studied prospect ively . NT-proBNP and troponin T were measured on admission . The primary end point was all-cause mortality at 30 days . Results Elevated NT-proBNP ( > 220 pmol/l ) was present in 65/244 patients ( 27.5 % ) and significantly predicted 30-day mortality ( OR 9.0 , 95 % CI 3.1 to 26.2 , p<0.001 ) . Elevated troponin T ( > 0.03 μg/l ) was found in 40/241 patients ( 16.6 % ) and also predicted 30-day mortality ( OR 6.3 , 95 % CI 2.4 to 16.5 , p<0.001 ) . These associations persisted after adjusting for other clinical and laboratory predictors of mortality ( arterial CO2 pressure ( Paco2 ) , body mass index and CURB65 score ) . NT-proBNP and troponin T levels appeared to have additive associations with mortality : 30-day mortality among patients with abnormalities of both NT-proBNP and troponin T was 15-fold higher than among patients with normal values . Conclusion Elevated levels of NT-proBNP and troponin T are strong predictors of early mortality among patients admitted to hospital with acute exacerbations of COPD independently of other known prognostic indicators . The pathophysiological basis for this is unknown , but indicates that cardiac involvement in exacerbations of COPD may be an important determinant of prognosis Patients with chronic obstructive pulmonary disease ( COPD ) are at increased risk of cardiovascular disease , exacerbations of which increase strain on the heart . The prognostic value of elevated circulating levels of cardiac Troponins seen during COPD exacerbations has been investigated . From the Akershus hospital data base , 897 patients discharged after treatment for COPD exacerbation in the period 2000–2003 were identified and followed-up until June 30 , 2005 . Median observation time was 1.9 yrs . In 396 patients , measurements of cardiac-specific troponin T ( cTnT ) were available . Levels of cTnT ≥0.04 μg·L−1 were considered elevated . Clinical data were retrieved from patient records and date of death was obtained from the Norwegian National Registry . In order to balance the nonr and omised nature of available cTnT measurements , an exposure propensity score ( EPS ) for cTnT sampling was calculated and used in regression analyses . After adjusting for EPS in Cox regression analyses , elevated cTnT was significantly associated with increased all-cause mortality in the observation period , with a hazard ratio of 1.64 ( 95 % confidence interval 1.15–2.34 ) . In conclusion , chronic obstructive pulmonary disease patients with elevated cardiac-specific Troponin T during exacerbation are at increased risk of death after discharge PURPOSE In chronic obstructive pulmonary disease ( COPD ) , cardiovascular system is involved but less is known about role of specific cardiac biomarkers . We aim ed to investigate associations between N-terminal pro B-type natriuretic peptide ( NT-proBNP ) and troponin T during hospitalisation with 6-month outcome . METHODS This was a prospect i ve study conducted in consecutive patients hospitalized for an acute exacerbation of COPD . On admission , and at discharge , NT-proBNP and troponin T were measured , and echocardiography was performed .  Hospitalisations and mortality were recorded for 6 months after discharge . RESULTS We included 127 patients ( 70 ± 10 years , 70 % men , GOLD III/IV 87 % ) . Left ventricular dysfunction was detected in 70 ( 55 % ) patients and diastolic dysfunction was the most common type ( 53 patients -42 % ) . NT-proBNP and troponin T were elevated on admission in 60 % and 36 % , and at discharge in 28 % and 19 % of patients . During follow-up , 53 ( 42 % ) patients were hospitalized and 17 ( 13 % ) patients died . In Kaplan Meier analysis of survival curves , NT-proBNP on admission distinguished between deceased and surviving patients ( p=0.011 ) whilst troponin T at discharge separated hospitalized and non-hospitalized patients ( p=0.017 ) . The adjusted Cox proportional hazard model confirmed these findings : discharge troponin T predicted hospitalisations ( hazard ratio 2.89 , 95 % confidence interval 1.13 - 7.36 ) and admission NT-proBNP predicted mortality ( hazard ratio 4.20 , 95 % confidence interval 1.07 - 14.01 ) . CONCLUSIONS Elevated NT-proBNP at discharge and troponin T on admission predict outcome in patients hospitalized for an acute exacerbation of COPD 
    Output:
    
Of the studies that used left ventricular ( LV ) dysfunction in AE COPD as an end point , all found a significant association between elevated BNP and troponins in the diagnosis of LV dysfunction .