***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 — Clinical observational studies on heart failure ( HF ) deal mostly with hospitalized patients , few with chronic out patients , all with no or limited longitudinal observation . Methods and Results —This is a multicenter , nationwide , prospect i ve observational trial on a population of 5610 patients , 1855 hospitalized for acute HF ( AHF ) and 3755 out patients with chronic HF ( CHF ) , followed up for 1 year . The cumulative total mortality rate at 1 year was 24 % in AHF ( 19.2 % in 797 patients with de novo HF and 27.7 % in 1058 with worsening HF ) and 5.9 % in CHF . Cardiovascular deaths accounted for 73.1 % and 65.3 % and HF deaths for 42.4 % and 40.5 % of total deaths in AHF and CHF patients , respectively . One-year hospitalization rates were 30.7 % in AHF and 22.7 % in CHF patients . Among the independent predictors of 1-year all-cause death , age , low systolic blood pressure , anemia , and renal dysfunction were identified in both acute and chronic patients . A few additional variables were significant only in AHF ( signs of cerebral hypoperfusion , low serum sodium , chronic obstructive pulmonary disease , and acute pulmonary edema ) , whereas others were observed only in CHF patients ( lower body mass index , higher heart rate , New York Heart Association class , large QRS , and severe mitral regurgitation ) . Conclusions —In this contemporary data set , patients with CHF had a relatively low mortality rate compared with those with AHF . Rates of adverse outcomes in patients admitted for AHF remain very high either in-hospital or after discharge . Most deaths were cardiovascular in origin and ≈40 % of deaths were directly related to HF AIMS We identified easily obtained baseline characteristics associated with outcomes in patients with chronic heart failure ( HF ) and elevated heart rate ( HR ) receiving contemporary guideline -recommended therapy in the SHIFT trial , and used them to develop a prognostic model . METHODS We selected the 10 best predictors for each of four outcomes ( cardiovascular death or HF hospitalisation ; all-cause mortality ; cardiovascular mortality ; and HF hospitalisation ) . All variables with p<0.05 for association were entered into a forward stepwise Cox regression model . Our initial analysis excluded baseline therapies , though r and omisation to ivabradine or placebo was forced into the model for the composite endpoint and HF hospitalisation . RESULTS Increased resting HR , low ejection fraction , raised creatinine , New York Heart Association class III/IV , longer duration of HF , history of left bundle branch block , low systolic blood pressure and , for three models , age were strong predictors of all outcomes . Additional predictors were low body mass index , male gender , ischaemic HF , low total cholesterol , no history of hyperlipidaemia or dyslipidaemia and presence of atrial fibrillation/flutter . The c-statistics for the four outcomes ranged from 67.6 % to 69.5 % . There was no evidence for lack of fit of the models with the exception of all-cause mortality ( p=0.017 ) . Similar results were found including baseline therapies . CONCLUSION The SHIFT Risk Model includes simple , readily obtainable clinical characteristics to produce important prognostic information in patients with chronic HF , systolic dysfunction , and elevated HR . This may help better calibrate management to individual patient risk Objectives The goal of this study was to determine the relative contribution of major lifestyle factors on the development of  heart failure ( HF ) in older adults . Background HF incurs high morbidity , mortality , and health care costs among adults ≥65 years of age , which is the most rapidly growing segment of the U.S. population . Methods We prospect ively investigated separate and combined associations of lifestyle risk factors with  incident HF ( 1,380 cases ) over 21.5 years among 4,490 men and women in the Cardiovascular Health Study , which is a community-based cohort of older adults . Lifestyle factors included 4  dietary patterns ( Alternative Healthy Eating Index , Dietary Approaches to Stop Hypertension , an American Heart Association 2020 dietary goals score , and a Biologic pattern , which was constructed using previous knowledge of cardiovascular disease dietary risk factors ) , 4  physical activity metrics ( exercise intensity , walking pace , energy expended in leisure activity , and walking distance )  , alcohol intake ,  smoking , and  obesity  . Results No dietary pattern was associated with developing HF ( p > 0.05 ) . Walking pace and leisure activity were associated with a 26 % and 22 % lower risk of HF , respectively ( pace > 3 mph vs. < 2 mph ; hazard ratio [ HR ] : 0.74 ; 95 % confidence interval [ CI ] : 0.63 to 0.86 ; leisure activity ≥845 kcal/week vs. < 845 kcal/week ; HR : 0.78 ; 95 % CI : 0.69 to 0.87 ) . Modest alcohol intake , maintaining a body mass index < 30 kg/m2 , and not smoking were also independently associated with a lower risk of HF . Participants with ≥4 healthy lifestyle factors had a 45 % ( HR : 0.55 ; 95 % CI : 0.42 to 0.74 ) lower risk of HF . Heterogeneity by age , sex , cardiovascular disease , hypertension medication use , and diabetes was not observed . Conclusions Among older U.S. adults , physical activity , modest alcohol intake , avoiding obesity , and not smoking , but not dietary patterns , were associated with a lower risk of HF Background —Heart failure ( HF ) is a prevalent and deadly disease , and preventive strategies focused on at-risk individuals are needed . Current HF prediction models have not examined HF subtypes . We sought to develop and vali date risk prediction models for HF with preserved and reduced ejection fraction ( HFpEF , HFrEF ) . Methods and Results —Of 28,820 participants from 4 community-based cohorts , 982 developed incident HFpEF and 909 HFrEF during a median follow-up of 12 years . Three cohorts were combined , and a 2:1 r and om split was used for derivation and internal validation , with the fourth cohort as external validation . Models accounted for multiple competing risks ( death , other HF subtype , and unclassified HF ) . The HFpEF-specific model included age , sex , systolic blood pressure , body mass index , antihypertensive treatment , and previous myocardial infa rct ion ; it had good discrimination in derivation ( c-statistic 0.80 ; 95 % confidence interval [ CI ] , 0.78–0.82 ) and validation sample s ( internal : 0.79 ; 95 % CI , 0.77–0.82 and external : 0.76 ; 95 % CI : 0.71–0.80 ) . The HFrEF-specific model additionally included smoking , left ventricular hypertrophy , left bundle branch block , and diabetes mellitus ; it had good discrimination in derivation ( c-statistic 0.82 ; 95 % CI , 0.80–0.84 ) and validation sample s ( internal : 0.80 ; 95 % CI , 0.78–0.83 and external : 0.76 ; 95 % CI , 0.71–0.80 ) . Age was more strongly associated with HFpEF , and male sex , left ventricular hypertrophy , bundle branch block , previous myocardial infa rct ion , and smoking with HFrEF ( P value for each comparison ⩽0.02 ) . Conclusions —We describe and vali date risk prediction models for HF subtypes and show good discrimination in a large sample . Some risk factors differed between HFpEF and HFrEF , supporting the notion of pathogenetic differences among HF subtypes BACKGROUND AND AIMS Hospitalized patients with heart failure who are malnourished present a worse prognosis than those with an adequate nutritional status . We undertook this study to assess whether a nutritional intervention in malnourished hospitalized patients with heart failure benefits morbidity and mortality . METHODS A multicenter , r and omized , controlled clinical trial was conducted . A total of 120 malnourished hospitalized patients due to acute heart failure were r and omised to conventional heart failure treatment or conventional heart failure treatment combined with an individualized nutritional intervention . The primary endpoint of this study was a composite of all-cause death or readmission for worsening of HF , with a maximum follow-up of 12 months . Analysis was by intention to treat . RESULTS Recruitment was stopped early according to the study protocol after completing the follow-up of the first 120 patients enrolled ( 59 in the intervention group and 61 in the control group ) . Both groups were homogeneous in baseline characteristics . At 12 months , the primary outcome occurred in 27.1 % of patients in the intervention group and in 60.7 % of patients in the control group ( hazard ratio 0.45 ; 95 % confidence interval [ CI ] , 0.19 - 0.62 , p = 0.0004 ) . In total , 20.3 % of patients died in the intervention group and 47.5 % in the control group ( hazard ratio 0.37 , 95 % CI , 0.19 - 0.72 , p = 0.003 ) . Readmission due to heart failure was also lower in the intervention group ( 10.2 vs. 36.1 % , p = 0.001 ) . CONCLUSION Nutritional intervention in malnourished hospitalized patients with heart failure reduces the risk of death from any cause and the risk of readmission for worsening of heart failure ( Clinical Trial.govNCT01472237 ) Aims We have investigated the role of muscle mass , natriuretic peptides and adipokines in explaining the obesity paradox . Background The obesity paradox relates to the association between obesity and increased survival in patients with coronary heart disease ( CHD ) or heart failure ( HF ) . Methods Prospect i ve study of 4046 men aged 60–79 years followed up for a mean period of 11 years , during which 1340 deaths occurred . The men were divided according to the presence of doctor diagnosed CHD and HF : ( i ) no CHD or HF ii ) , with CHD ( no HF ) and ( iii ) with HF . Results Overweight ( BMI 25–9.9 kg/m2 ) and obesity ( BMI ≥ 30 kg/m2 ) were associated with lower mortality risk compared to men with normal weight ( BMI 18.5–24.9 kg/m2 ) in those with CHD [ hazards ratio ( HR ) 0.71 ( 0.56,0.91 ) and 0.77 ( 0.57,1.04 ) ; p = 0.04 for trend ] and in those with HF [ HR 0.57 ( 0.28,1.16 ) and 0.41 ( 0.16,1.09 ; p = 0.04 for trend ) . Adjustment for muscle mass and NT-proBNP attenuated the inverse association in those with CHD ( no HF ) [ HR 0.78 ( 0.61,1.01 ) and 0.96 ( 0.68,1.36 ) p = 0.60 for trend ) but made minor differences to those with HF [ p = 0.05 ] . Leptin related positively to mortality in men without HF but inversely to mortality in those with HF ; adjustment for leptin abolished the BMI mortality association in men with HF [ HR 0.82 ( 0.31,2.20 ) and 0.99 ( 0.27,3.71 ) ; p = 0.98 for trend ] . Conclusion The lower mortality risk associated with excess weight in men with CHD without HF may be due to higher muscle mass . In men with HF , leptin ( possibly reflecting cachexia ) explain the inverse association Background —Skeletal muscle dysfunction and exercise intolerance are clinical hallmarks of patients with heart failure . These have been linked to a progressive catabolic state , skeletal muscle inflammation , and impaired oxidative metabolism . Previous studies suggest beneficial effects of & ohgr;-3 polyunsaturated fatty acids and glutamine on exercise performance and muscle protein balance . Methods and Results —In a r and omized double-blind , placebo-controlled trial , 31 patients with heart failure were r and omized to either L-alanyl-L-glutamine ( 8 g/d ) and polyunsaturated fatty acid ( 6.5 g/d ) or placebo ( safflower oil and milk powder ) for 3 months .  Cardiopulmonary exercise testing , dual-energy x-ray absorptiometry , 6-minute walk test , h and grip strength , functional muscle testing , echocardiography , and quality of life and lateral quadriceps muscle biopsy  were performed at baseline and at follow-up . Oxidative capacity and metabolic gene expression were analyzed on muscle biopsies . No differences in muscle function , echocardiography , 6-minute walk test , or h and grip strength and a nonsignificant increase in peak VO2 in the treatment group 
    Output:
    
Nutritional disorders  are prevalent in patients with CHF and play a significant role in the incidence , course , and prognosis of the disease .