***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 
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    ***EXAMPLES*** 
    Input: Background —The determinants of prognosis in patients with heart failure and preserved ejection fraction ( HF-PEF ) are poorly documented . Methods and Results —We evaluated data from 4128 patients in the I-PRESERVE trial ( Irbesartan in Heart Failure with Preserved Ejection Fraction Study ) . Multivariable Cox regression models were developed using 58 baseline demographic , clinical , and biological variables to model the primary outcome of all-cause mortality or cardiovascular hospitalization ( 1505 events ) , all-cause mortality ( 881 events ) , and HF death or hospitalization ( 716 events ) . Log N-terminal pro – B-type natriuretic peptide , age , diabetes mellitus , and previous hospitalization for HF were the most powerful factors associated with the primary outcome and with the HF composite . For all-cause mortality , log N-terminal pro – B-type natriuretic peptide , age , diabetes mellitus , and left ventricular EF were the strongest independent factors . Other independent factors associated with poor outcome included quality of life , a history of chronic obstructive lung disease , log neutrophil count , heart rate , and estimated glomerular filtration rate . The models accurately stratified the actual 3-year rate of outcomes from 8.1 % to 59.9 % ( primary outcome ) 2.7 % to 36.5 % ( all-cause mortality ) , and 2.1 % to 38.9 % ( HF composite ) for the lowest to highest septiles of predicted risks . Conclusions —In a large sample of elderly patients with HF and preserved EF enrolled in I-Preserve , simple clinical , demographic , and biological variables were associated with outcome and identified subgroups at very high and very low risk of events . Clinical Trial Registration —URL : http://www . clinical trials.gov . Unique identifier : NCT00095238 Background —Exercise intolerance is the primary symptom in older patients with heart failure and preserved ejection fraction ( HFPEF ) ; however , little is known regarding its mechanisms and therapy . Methods and Results —Seventy-one stable elderly ( 70±1 years ) patients ( 80 % women ) with compensated HFPEF and controlled blood pressure were r and omized into a 12-month follow-up double-blind trial of enalapril 20 mg/d versus placebo . Assessment s were peak exercise oxygen consumption ; 6-minute walk test ; Minnesota Living with HF Question naire ; MRI ; Doppler echocardiography ; and vascular ultrasound . Compliance by pill count was excellent ( 94 % ) . Twenty-five patients in the enalapril group versus 34 in the placebo group completed the 12-month follow-up . During follow-up , there was no difference in the primary outcome of peak exercise oxygen consumption  ( enalapril , 14.5±3.2 mL/kg/min ; placebo , 14.3±3.4 mL/kg/min ; P=0.99 ) , or in 6-minute walk distance , aortic distensibility ( the primary mechanistic outcome ) , left ventricle mass , or neurohormonal profile . The effect size of enalapril  on peak exercise oxygen consumption was small ( 0.7 % ; 95 % CI , 4.2 % to 5.6 % ) . There was a trend toward improved Minnesota Living with HF Question naire total score ( P=0.07 ) , a modest reduction in systolic blood pressure at peak exercise ( P=0.02 ) , and a marginal improvement in carotid arterial distensibility ( P=0.04 ) . Conclusions —In stable , older patients with compensated HFPEF and controlled blood pressure , 12 months of enalapril did not improve exercise capacity or aortic distensibility . These data , combined with those from large clinical event trials , suggest that angiotensin inhibition does not substantially improve key long-term clinical outcomes in this group of patients . This finding contrasts sharply with observations in HF with reduced EF and highlights our incomplete underst and ing of this important and common disorder BACKGROUND Preliminary evidence suggests that meditative exercise may have benefits for patients with chronic systolic heart failure ( HF ) ; this has not been rigorously tested in a large clinical sample . We sought to investigate whether tai chi , as an adjunct to st and ard care , improves functional capacity and quality of life in patients with HF . METHODS A single-blind , multisite , parallel-group , r and omized controlled trial evaluated 100 out patients with systolic HF ( New York Heart Association class I-III , left ventricular ejection fraction ≤40 % ) who were recruited between May 1 , 2005 , and September 30 , 2008 . A group-based 12-week tai chi exercise program ( n = 50 ) or time-matched education ( n = 50 , control group ) was conducted . Outcome measures included exercise capacity ( 6- minute walk test and peak oxygen uptake ) and disease-specific quality of life ( Minnesota Living With Heart Failure Question naire ) . RESULTS Mean ( SD ) age of patients was 67 ( 11 ) years ; baseline values were left ventricular ejection fraction , 29 % ( 8 % ) and peak oxygen uptake , 13.5 mL/kg/min ; the median New York Heart Association class of HF was class II . At completion of the study , there were no significant differences in change in 6-minute walk distance and peak oxygen uptake ( median change [ first quartile , third quartile ] , 35 [ -2 , 51 ] vs 2 [ -7 , 54 ] meters , P = .95 ; and 1.1 [ -1.1 , 1.5 ] vs -0.5 [ -1.2 , 1.8 ] mL/kg/min , P = .81 ) when comparing tai chi and control groups ; however , patients in the tai chi group had greater improvements in quality of life ( Minnesota Living With Heart Failure Question naire , -19 [ -23 , -3 ] vs 1 [ -16 , 3 ] , P = .02 ) . Improvements with tai chi were also seen in exercise self-efficacy ( Cardiac Exercise Self-efficacy Instrument , 0.1 [ 0.1 , 0.6 ] vs -0.3 [ -0.5 , 0.2 ] , P < .001 ) and mood ( Profile of Mood States total mood disturbance , -6 [ -17 , 1 ] vs -1 [ -13 , 10 ] , P = .01 ) . CONCLUSION Tai chi exercise may improve quality of life , mood , and exercise self-efficacy in patients with HF . Trial Registration clinical trials.gov Identifier : NCT00110227 Background — Exercise training reduces the symptoms of chronic heart failure . Which exercise intensity yields maximal beneficial adaptations is controversial . Furthermore , the incidence of chronic heart failure increases with advanced age ; it has been reported that 88 % and 49 % of patients with a first diagnosis of chronic heart failure are > 65 and > 80 years old , respectively . Despite this , most previous studies have excluded patients with an age > 70 years . Our objective was to compare training programs with moderate versus high exercise intensity with regard to variables associated with cardiovascular function and prognosis in patients with postinfa rct ion heart failure . Methods and Results — Twenty-seven patients with stable postinfa rct ion heart failure who were undergoing optimal medical treatment , including & bgr;-blockers and angiotensin-converting enzyme inhibitors ( aged 75.5±11.1 years ; left ventricular [ LV ] ejection fraction 29 % ; & OV0312;o2peak 13 mL · kg−1 · min−1 ) were r and omized to either moderate continuous training ( 70 % of highest measured heart rate , ie , peak heart rate ) or aerobic interval training ( 95 % of peak heart rate ) 3 times per week for 12 weeks or to a control group that received st and ard advice regarding physical activity . & OV0312;o2peak increased more with aerobic interval training than moderate continuous training ( 46 % versus 14 % , P<0.001 ) and was associated with reverse LV remodeling . LV end-diastolic and end-systolic volumes declined with aerobic interval training only , by 18 % and 25 % , respectively ; LV ejection fraction increased 35 % , and pro-brain natriuretic peptide decreased 40 % . Improvement in brachial artery flow-mediated dilation ( endothelial function ) was greater with aerobic interval training , and mitochondrial function in lateral vastus muscle increased with aerobic interval training only . The MacNew global score for quality of life in cardiovascular disease increased in both exercise groups . No changes occurred in the control group . Conclusions — Exercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity , endothelial function , and quality of life in patients with postinfa rct ion heart failure . These findings may have important implication s for exercise training in rehabilitation programs and future studies AIMS Diastolic dysfunction ( DD ) was identified as a predictor of adverse prognosis in heart failure with reduced ejection fraction ( HFREF ) . It is , however , unknown if DD is improved by exercise training , which is known to induce reverse remodelling , and if the training effect is attenuated in elderly HFREF patients . We therefore assessed DD in a cohort of referent controls ( RCs ) and HFREF patients and studied the response of DD to endurance exercise in two age groups ( ≤55 years and ≥65 years ) . METHODS AND RESULTS Sixty RC ( 30 ≤ 55 years , mean age 50 ± 5 years ; 30 ≥ 65 years , 72 ± 4 years ) and 60 HFREF patients ( 30 ≤ 55 years , 46 ± 5 years ; 30 ≥ 65 years , 72 ± 5 years , EF 28 ± 5 % ) were r and omized to 4 weeks of supervised endurance training or to a control group . Exercise training was effective in reducing LV isovolumetric relaxation time by 29 % in young and by 26 % in old HFREF patients ( P < 0.05 for both ) . As assessed by tissue Doppler , septal E ' increased by 37 % in young and by 39 % among old HFREF patients ( P < 0.005 for both ) result ing in a significant decrease in the E/E ' ratio from 13 ± 1 to 10 ± 1 in young and 14 ± 1 to 11 ± 1 in old HFREF patients ( P < 0.05 for both ) . Serum levels of N-terminal pro brain natriuretic peptide were significantly reduced after endurance training in HFREF patients of all ages . CONCLUSION In HFREF , diastolic function is significantly impaired in all age groups  . Endurance training is highly effective in improving left ventricular diastolic function in HFREF patients regardless of age . This study is registered at Clinical Trials.gov ( number : NCT00176319 ) AIMS The purpose of this study was to evaluate whether yoga training in addition to st and ard medical therapy can improve cardiac function and reduce N terminal pro B-type natriuretic peptide ( NT pro BNP ) in heart failure ( HF ) . METHODS 130 patients were recruited and r and omized into two groups : Control Group ( CG ) ( n = 65 ) , Yoga Group ( YG ) . In YG , 44 patients and in CG , 48 patients completed the study . Cardiac function using left ventricular ejection fraction ( LVEF ) , myocardial performance index ( Tei index ) , and NT pro BNP , a biomarker of HF , was assessed at baseline and after 12 weeks . RESULT Improvement in LVEF , Tei index , and NT pro BNP were statistically significant in both the groups . Furthermore , when the changes in before and after 12 weeks were in percentage , LVEF increased 36.88 % in the YG and 16.9 % in the CG , Tei index was reduced 27.87 % in the YG and 2.79 % in the CG , NT pro BNP was reduced 63.75 % in the YG and 10.77 % in the CG . The between group comparisons from pre to post 12 weeks were significant for YG improvements ( LVEF , P < 0.01 , Tei index , P < 0.01 , NT pro BNP , P < 0.01 ) . CONCLUSION These results indicate that the addition of yoga therapy to st and ard medical therapy for HF patients has a markedly better effect on cardiac function and reduced myocardial stress measured using NT pro BNP in patients with stable HF Purpose Most training studies in patients with chronic heart failure ( CHF ) do not consider CHF aetiology in the interpretation of the results . About 60 % of the patients in those studies have ischemic CHF ( IHF ) and 40 % non-ischemic CHF ( NHF ) . Recently , we conducted a r and omized controlled trial to study three different training modalities in 60 patients with severe CHF , with a similar distribution of IHF and NHF patients . In the present post hoc analysis we compared the differences in training results between ischemic and non-ischemic patients . Methods Left ventricular ejection fraction ( EF ) , end diastolic volume ( EDV ) , end systolic volume ( ESV ) , measured with radionuclide ventriculography ( RNV ) and echocardiography , NT-pro BNP , peak oxygen uptake ( peak $ $ V_{{{\rm O}_{2 } } } $ $ ) , working 
    Output:
    
Limited evidence exists as to the effect of exercise training on emerging biomarkers