***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 —Myocardial ischemia and infa rct ion impair baroreflex sensitivity ( BRS ) , which when depressed is predictive of future cardiac events after myocardial infa rct ion ( MI ) . The main objective of this study was to determine whether exercise training improves BRS in patients with coronary artery disease . Methods and Results —Ninety-seven male patients with and without a previous MI were recruited after myocardial revascularization surgery and r and omized into trained ( TR ) or untrained ( UTR ) groups . TR patients underwent a residential exercise program at 85 % of maximum heart rate ( HRmax ) consisting of 2 daily sessions 6 times a week for 2 weeks . Eighty-six patients ( 45 TR and 41 UTR ) completed the study . BRS was assessed at baseline and at the end of the protocol by the spontaneous baroreflex method . The st and ard deviation of mean R-R interval ( RRSD ) was also assessed as a measure of heart rate variability . At baseline , there were no significant differences between TR and UTR patients in any variable . In TR patients , BRS increased from 3.0±0.3 to 5.3±0.7 ms/mm Hg ( P < 0.001 ) , RRSD from 18.7±1.4 to 23.6±1.6 ms ( P < 0.01 ) , and R-R interval from 792.0±15.5 to 851.3±20.5 ms ( P < 0.001 ) . No significant changes occurred in UTR patients . Increases in BRS and RRSD were significant in patients either with or without a previous MI . Conclusions —Exercise training  increases BRS and heart rate variability in patients with coronary artery disease . Improved cardiac autonomic function might add to the other benefits of exercise training in secondary prevention of ischemic heart disease In a multicentre trial 742 patients in 13 hospitals in Wales were r and omly allocated on the fifth day after uncomplicated myocardial infa rct ion to be mobilised on the fifth or the tenth day . The trial shows no difference in first year mortality , nor in morbidity assessed after a median period of 13 months . Follow-up after one year suggests an unexplained lower mortality during the second and third years in the late mobilisation group Abstract The effects of early mobilization after uncomplicated myocardial infa rct ion were investigated in a strictly r and omized controlled study conducted during a period of transition in the therapeutic practice of the Cantonal Hospital in Geneva , Switzerl and . One hundred fifty-four patients under age 70 who were hospitalized for acute myocardial infa rct ion and who had no complications on day 1 or day 2 were r and omly assigned to two treatment groups . In the early mobilization group , patients were treated by a physical therapist with a progressive activity program beginning on day 2 or 3 after infa rct ion . In the control group , patients underwent the traditional hospital regimen of strict bed rest for 3 or more weeks . The mean duration of hospitalization was 21.3 days for treated patients and 32.8 days for the control group . The follow-up period ranged from 6 to 20 ( average 11.2 ) months . There were no statistically significant differences between the two groups with regard to hospital or follow-up mortality , rate of reinfa rct ion , arrhythmias , heart failure , angina pectoris or ventricular aneurysm , or results of an exercise test . There was significantly greater disability in the control than in the treated group on follow-up examination . This controlled trial , based on a rigid experimental design , provides important confirmation of the benefits of early mobilization observed in uncontrolled programs in recent years Background —The predictive value of heart rate variability ( HRV ) in chronic heart failure ( CHF ) has never been tested in a comprehensive multivariate model using short-term laboratory recordings design ed to avoid the confounding effects of respiration and behavioral factors . Methods and Results —A multivariate survival model for the identification of sudden ( presumably arrhythmic ) death was developed with data from 202 consecutive patients referred between 1991 and 1995 with moderate to severe CHF ( age 52±9 years , left ventricular ejection fraction 24±7 % , New York Heart Association class 2.3±0.7 ; the derivation sample ) .  Time- and frequency-domain HRV parameters obtained from an 8′ recording of ECG at baseline and during controlled breathing ( 12 to 15 breaths/min ) were challenged against clinical and functional parameters . This model was then vali date d in 242 consecutive patients referred between 1996 and 2001 ( validation sample ) . In the derivation sample , sudden death was independently predicted by a model that included low-frequency power ( LFP ) of HRV during controlled breathing ≤13 ms2 and left ventricular end-diastolic diameter ≥77 mm ( relative risk [ RR ] 3.7 , 95 % CI 1.5 to 9.3 , and RR 2.6 , 95 % CI 1.0 to 6.3 , respectively ) . The derivation model was also a significant predictor in the validation sample ( P = 0.04 ) . In the validation sample , LFP ≤11 ms2 during controlled breathing and ≥83 ventricular premature contractions per hour on Holter monitoring were both independent predictors of sudden death ( RR 3.0 , 95 % CI 1.2 to 7.6 , and RR 3.7 , 95 % CI 1.5 to 9.0 , respectively ) . Conclusions —Reduced short-term LFP during controlled breathing is a powerful predictor of sudden death in patients with CHF that is independent of many other variables . These results refine the identification of patients who may benefit from prophylactic implantation of a cardiac defibrillator A total of 189 patients with uncomplicated myocardial infa rct ion were selected at r and om for early or late mobilization and discharge from hospital . Patients were admitted to the study after 48 hours in a coronary care unit if they were free of pain and showed no evidence of heart failure or significant dysrhythmia . R and omization was achieved by monthly cross-over of the three medical wards to which the patients were discharged . One group of patients was mobilized immediately and discharged home after a total of nine days in hospital , and the second group was mobilized on the ninth day and discharged on the 16th day . Out-patient assessment was carried out six weeks after admission . No significant differences were observed between the groups in terms of mortality or morbidity , as reflected by the incidence of recurrent chest pain or myocardial infa rct ion , heart failure , dysrhythmia , or venous thromboembolism detected either clinical ly or by 125I-labelled fibrinogen scanning CONTEXT Trials comparing primary percutaneous coronary intervention ( PCI ) and thrombolytic therapy for treatment of acute myocardial infa rct ion ( MI ) suggest primary PCI is the superior therapy , although they differ with respect to the durability of benefit . Because PCI is often limited to hospitals that have on-site cardiac surgery programs , most acute MI patients do not have access to this therapy . OBJECTIVE To determine whether treatment of acute MI with primary PCI is superior to thrombolytic therapy at hospitals without on-site cardiac surgery and , if so , whether superiority is durable . DESIGN The Atlantic Cardiovascular Patient Outcomes Research Team ( C-PORT ) trial , a prospect i ve , r and omized trial conducted from July 1996 through December 1999 . SETTING Eleven community hospitals in Massachusetts and Maryl and without on-site cardiac surgery or extant PCI programs . PATIENTS Four hundred fifty-one thrombolytic-eligible patients with acute MI of less than 12 hours ' duration associated with ST-segment elevation on electrocardiogram . INTERVENTIONS After a formal primary PCI development program was completed at all sites , patients were r and omly assigned to receive primary PCI ( n = 225 ) or accelerated tissue plasminogen activator ( bolus dose of 15 mg and an infusion of 0.75 mg/kg for 30 minutes followed by 0.5 mg/kg for 60 minutes ; n = 226 ) . After initiation of assigned treatment , all care was determined by treating physicians . MAIN OUTCOME MEASURES Six-month composite incidence of death , recurrent MI , and stroke ; median hospital length of stay . RESULTS The incidence of the composite end point was reduced in the primary PCI group at 6 weeks ( 10.7 % vs 17.7 % ; P = .03 ) and 6 months ( 12.4 % vs 19.9 % ; P = .03 ) after index MI . Six-month rates for individual outcomes were 6.2 % vs 7.1 % for death ( P = .72 ) , 5.3 % vs 10.6 % for recurrent MI ( P = .04 ) , and 2.2 % vs 4.0 % for stroke ( P = .28 ) for primary PCI vs thrombolytic therapy , respectively . Median length of stay was also reduced in the primary PCI group ( 4.5 vs 6.0 days ; P = .02 ) . CONCLUSIONS Compared with thrombolytic therapy , treatment of patients with primary PCI  at hospitals without on-site cardiac surgery is associated with better clinical outcomes for 6 months after index MI and a shorter hospital stay BACKGROUND In patients with ST-segment elevated myocardial infa rct ion ( STEMI ) , early post-thrombolysis routine angioplasty has been discouraged because of its association with high incidence of events . The GRACIA-1 trial was design ed to reassess the benefits of an early post-thrombolysis interventional approach in the era of stents and new antiplatelet agents . METHODS 500 patients with thrombolysed STEMI ( with recombinant tissue plasminogen activator ) were r and omly assigned to angiography and intervention if indicated within 24 h of thrombolysis  , or to an ischaemia-guided conservative approach . The primary endpoint was the combined rate of death , reinfa rct ion , or revascularisation at 12 months . Analysis was by intention to treat . FINDINGS Invasive treatment included stenting of the culprit artery in 80 % ( 199 of 248 ) patients , bypass surgery in six ( 2 % ) , non-culprit artery stenting in three , and no intervention in 40 ( 16 % ) . Predischarge revascularisation was needed in 51 of 252 patients in the conservative group . By comparison with patients receiving conservative treatment , by 1 year , patients in the invasive group had lower frequency of primary endpoint ( 23 [ 9 % ] vs 51 [ 21 % ] , risk ratio 0.44 [ 95 % CI 0.28 - 0.70 ] , p=0.0008 ) , and they tended to have reduced rate of death or reinfa rct ion ( 7 % vs 12 % , 0.59 [ 0.33 - 1.05 ] , p=0.07 ) . Index time in hospital was shorter in the invasive group , with no differences in major bleeding or vascular complications . At 30 days both groups had a similar incidence of cardiac events . In-hospital incidence of revascularisation induced by spontaneous recurrence of ischaemia was higher in patients in the conservative group than in those in the invasive group . INTERPRETATION In patients with STEMI , early post-thrombolysis catheterisation and appropriate intervention is safe and might be preferable to a conservative strategy since it reduces the need for unplanned in-hospital revascularisation , and improves 1-year clinical outcome To determine the effects of early ambulation on peripheral venous thrombosis in the coronary care unit , 29 patients with acute myocardial infa rct ion had daily 125I-fibrinogen point counting of both legs using a st and ard portable technique in the first 3 to 7 days after admission . Twenty-one patients underwent early ambulation during the initial 3 days , while 8 remained at complete bed rest for 5 days . Only 2 of 21 early ambulated patients had positive fibrinogen point counts , in contrast to 5 of 8 nonambulated patients ( P less than 0.01 ) . With heart failure , only 2 of 9 ambulated patients had positive point counts , compared with 4 of 5 nonambulated patients ( P less than 0.05 ) . In 16 patients undergoing venography  , point counts were confirmed in 6 positive and 10 negative findings . These results show that the high frequency of peripheral venous thrombosis in immobilized acute myocardial infa rct ion patients , particularly those with heart failure , can be effectively reduced by early ambulation Early mobilisation  after acute myocardial infa rct ion is said to increase the risk of ventricular aneurysm and -rupture , reinfa rct ion , sudden death , and heart failure . In order to evaluate these possible negative effects , we run a prospect i ve and controlled study : 2 X 100 consecutive patients with acute myocardial infa rct ion were mobilized conventionally ( A ) and according to an early mobilisation programme ( B ) respectively-the two groups were comparable according to age , sex , CHD-history , infa rct ion transmural/non transmural and coronary prognostic index ( Norris ) . There was a significant reduction in the average hospital stay from 31.4 days in group A to 25.8 in group B. The patients were followed up for 32 ( A ) and 46 days ( B ) respectively . In the early mobilized group we found no increased risk for heart failure , reinfa rct ion , or sudden death . On the other side , early mobilisation has many psychological , oeconomic and social advantages for patients and hospital A 
    Output:
    
Our meta- analysis demonstrated a trend towards decreased mortality with EM after AMI .