***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: Of 22 r and omized trials of rehabilitation with exercise  after myocardial infa rct ion ( MI ) , one trial had results that achieved conventional statistical significance . To determine whether or not these studies , in the aggregate , show a significant benefit of rehabilitation after myocardial infa rct ion , we performed an overview of all r and omized trials , involving 4,554 patients ; we evaluated total and cardiovascular mortality , sudden death , and fatal and nonfatal reinfa rct ion . For each endpoint , we calculated an odds ratio ( OR ) and 95 % confidence interval ( 95 % CI ) for the trials combined . After an average of 3 years of follow-up , the ORs were significantly lower in the rehabilitation than in the comparison group : specifically , total mortality ( OR = 0.80 [ 0.66 , 0.96 ] ) , cardiovascular mortality ( OR = 0.78 [ 0.63 , 0.96 ] ) , and fatal reinfa rct ion ( OR = 0.75 [ 0.59 , 0.95 ] ) . The OR for sudden death was significantly lower in the rehabilitation than in the comparison group at 1 year ( OR = 0.63 [ 0.41 , 0.97 ] ) . The data were compatible with a benefit at 2 ( OR = 0.76 [ 0.54 , 1.06 ] ) and 3 years ( OR = 0.92 [ 0.69 , 1.23 ] ) , but these findings were not statistically significant . For nonfatal reinfa rct ion , there were no significant differences between the two groups after 1 ( OR = 1.09 [ 0.76 , 1.57 ] ) , 2 ( OR = 1.10 [ 0.82 , 1.47 ] ) , or 3 years ( OR = 1.09 [ 0.88 , 1.34 ] ) of follow-up . The observed 20 % reduction in overall mortality reflects a decreased risk of cardiovascular mortality and fatal reinfa rct ion throughout at least 3 years and a reduction in sudden death during the 1st year after infa rct ion and possibly for 2 - 3 years . With respect to the independent effects of the physical exercise component of cardiac rehabilitation , the relatively small number of " exercise only " trials , combined with the possibility that they may have had a formal or informal nonexercise component precludes the possibility of reaching any definitive conclusion . To do so would require a r and omized trial of sufficient size to distinguish between no effect and the most plausible effect based on the results of this overview BACKGROUND Recent clinical trials have shown that modification of plasma lipoprotein concentrations can favorably alter progression of coronary atherosclerosis , but no data exist on the effects of a comprehensive program of risk reduction involving both changes in lifestyle and medications . This study tested the hypothesis that intensive multiple risk factor reduction over 4 years would significantly reduce the rate of progression of atherosclerosis in the coronary arteries of men and women compared with subjects r and omly assigned to the usual care of their physician .  METHODS AND RESULTS Three hundred men ( n = 259 ) and women ( n = 41 ) ( mean age , 56 + /- 7.4 years ) with angiographically defined coronary atherosclerosis were r and omly assigned to usual care ( n = 155 ) or multifactor risk reduction ( n = 145 ) . Patients assigned to risk reduction were provided individualized programs involving a low-fat and -cholesterol diet , exercise , weight loss , smoking cessation , and medications to favorably alter lipoprotein profiles . Computer-assisted quantitative coronary arteriography was performed at baseline and after 4 years . The main angiographic outcome was the rate of change in the minimal diameter of diseased segments . All subjects underwent medical and risk factor evaluations at baseline and yearly for 4 years , and reasons for all hospitalizations and deaths were documented . Of the 300 subjects r and omized , 274 ( 91.3 % ) completed a follow-up arteriogram , and 246 ( 82 % ) had comparative measurements of segments with visible disease at baseline and follow-up . Intensive risk reduction result ed in highly significant improvements in various risk factors , including low-density lipoprotein cholesterol and apolipoprotein B ( both , 22 % ) , high-density lipoprotein cholesterol ( + 12 % ) , plasma triglycerides ( -20 % ) , body weight ( -4 % ) , exercise capacity ( + 20 % ) , and intake of dietary fat ( -24 % ) and cholesterol ( -40 % ) compared with relatively small changes in the usual-care group . No change was observed in lipoprotein(a ) in either group . The risk-reduction group showed a rate of narrowing of diseased coronary artery segments that was 47 % less than that for subjects in the usual-care group ( change in minimal diameter , -0.024 + /- 0.066 mm/y versus -0.045 + /- 0.073 mm/y ; P < .02 , two-tailed ) . Three deaths occurred in each group . There were 25 hospitalizations in the risk-reduction group initiated by clinical cardiac events compared with 44 in the usual-care group ( rate ratio , 0.61 ; P = .05 ; 95 % confidence interval , 0.4 to 0.9 ) . CONCLUSIONS Intensive multifactor risk reduction conducted over 4 years favorably altered the rate of luminal narrowing in coronary arteries of men and women with coronary artery disease and decreased hospitalizations for clinical cardiac events Background Significant regression of coronary and femoral atherosclerotic lesions has been documented by angiographic studies using aggressive lipid-lowering treatment . This study tested the applicability and effects of intensive physical exercise and low-fat diet on coronary morphology and myocardial perfusion in nonselected patients with stable angina pectoris . Methods and Results Patients were recruited after routine coronary angiography for stable angina pectoris ; they were r and omized to an  intervention group ( n = 56 ) and a  control group on “ usual care ” ( n = 57 ) . Treatment comprised intensive physical exercise in group training sessions ( minimum , 2 hr/wk ) , daily home exercise periods ( 20 min/d ) , and low-fat , low-cholesterol diet ( American Heart Association recommendation , phase 3 ) . No lipid-lowering agents were prescribed . After 12 months of participation , repeat coronary angiography was performed ; relative and minimal diameter reductions of coronary lesions were measured by digital image processing . Change in myocardial perfusion was assessed by 201TI scintigraphy . In patients participating in the intervention group , body weight decreased by 5 % ( p<0.001 ) , total cholesterol by 10 % ( p<0.001 ) , and triglycerides by 24 % ( p<0.001 ) ; high density lipoproteins increased by 3 % ( p = NS ) . Physical work capacity improved by 23 % ( p<0.0001 ) , and myocardial oxygen consumption , as estimated from maximal rate-pressure product , by 10 % , ( p<0.05 ) . Stress-induced myocardial ischemia decreased concurrently , indicating improvement of myocardial perfusion . Based on minimal lesion diameter , progression of coronary lesions was noted in nine patients ( 23 % ) , no change in 18 patients ( 45 % ) , and regression in 13 patients ( 32 % ) . In the control group , metabolic and hemodynamic variables remained essentially unchanged , whereas progression of coronary lesions was noted in 25 patients ( 48 % ) , no change in 18 patients ( 35 % ) , and regression in nine patients ( 17 % ) . These changes were significantly different from the intervention group ( p<0.05 ) . Conclusions In patients participating in regular physical exercise and low-fat diet , coronary artery disease progresses at a slower pace compared with a control group on usual care Every second of non-selected men below the age of 55 years who had survived a myocardial infa rct ion was placed in a group for physical training , while each other constituted a control . The physical training program was selected according to each patient 's individual maximal working capacity and lasted for 9 months , beginning 3 months after the myocardial infa rct ion . At the end of the training period the experimental group was subdivided into one group of adequately trained patients and one consisting of drop-outs and patients with poor adherence . The patients who followed the program increased their physical work performance . In this group a decrease was found in plasma insulin values after a glucose tolerance test , a slight increase in glucose tolerance and a decrease in body fat and plasma triglycerides . Body cell mass and plasma cholesterol did not change . The men selected for the training program , but who were not able to follow it sufficiently , as well as the controls , showed a less marked decrease in plasma insulin values at reexamination In this study , 113 patients with modestly elevated levels of low-density lipoprotein cholesterol ( < 210 mg/dl ) and coronary artery disease were r and omized to an  intervention group ( n=56 ) or a control group ( n=57 ) . The intervention program consisted of daily exercise and a low-fat diet according to the American Heart Association 's recommendation phase III ; patients in the control group received " usual care " rendered by their private physician . After 1 year , complete data were available for all 92 patients ( intervention : n=40 ; control : n=52 ) who underwent repeat coronary angiography .  During the study course , patients in the intervention group showed an increase in apolipoprotein A-I(123 + /- 18 vs 129 + /- 20 mg/dl ; p < 0.02 ) and apolipoprotein A-I/B ( 1.3 + /- 0.4 vs 1.5 + /- 0.4 ; p < 0.01 ) and a decrease in apolipoprotein B ( 99 + /- 20 vs 89 + /- 18 mg/dl ; p < 0.01 ) , while apolipoprotein A-II remained unchanged ( 38 + /- 6 vs 38 + /- 6 mg/dl ; p = NS ) . In the control group , there were no significant changes ( apolipoprotein A-I , 124 + /- 17 vs 128 + /- 13 mg/dl ; apolipoprotein A-II , 38 + /- 6 vs 39 + /- 6 mg/dl ; apolipoprotein B , 100 + /- 21 vs 99 + /- 16 mg/dl ; apolipoprotein A-I/B , 1.3 + /- 0.3 vs 1.4 + /- 0.5 ; all p = NS ) . As previously reported , there was a significant retardation of progression in patients in the intervention group ( progression 23 % , no change 45 % , regression 32 % ) compared with the control group ( progression 48 % , no change 35 % , regression 17 % ) ( p < 0.05 ) . Although retardation of progression was significantly associated with an increase in apolipoprotein A-I/B and a decrease in apolipoprotein B ( p < 0.05 ) , these gave way in multivariate analysis to changes in total cholesterol/high-density lipoprotein cholesterol , absolute levels of low-density lipoprotein cholesterol , and , in a subgroup of patients , to leisure-time physical activity ( all p < 0.05 ) . These data demonstrate that an intervention based on a low-fat diet and intensive physical exercise is capable of improving apolipoprotein levels , associated with retardation of progression of coronary artery disease . However ,  total cholesterol/high-density lipoprotein cholesterol and low-density lipoprotein cholesterol  appear superior to apolipoproteins as metabolic markers for effective treatment in patients with coronary artery disease In a prospect i ve , r and omised , controlled trial to determine whether comprehensive lifestyle changes affect coronary atherosclerosis after 1 year , 28 patients were assigned to an experimental group ( low-fat vegetarian diet , stopping smoking , stress management training , and moderate exercise ) and 20 to a usual-care control group . 195 coronary artery lesions were analysed by quantitative coronary angiography  . The average percentage diameter stenosis regressed from 40.0 ( SD 16.9)% to 37.8 (16.5)% in the experimental group yet progressed from 42.7 (15.5)% to 46.1 (18.5)% in the control group . When only lesions greater than 50 % stenosed were analysed , the average percentage diameter stenosis regressed from 61.1 (8.8)% to 55.8 (11.0)% in the experimental group and progressed from 61.7 (9.5)% to 64.4 (16.3)% in the control group . Overall , 82 % of experimental-group patients had an average change towards regression .  Comprehensive lifestyle changes may be able to bring about regression of even severe coronary atherosclerosis after only 1 year , without use of lipid-lowering drugs To determine the influence of exercise training on  smoking after acute myocardial infa rct ion ( AMI ) , smoking rates in 42 pre-AMI smokers assigned to exercise training were compared with 26 pre-AMI smokers assigned to no training . Exercise training occurred  
    Output:
    
REVIEW ER 'S CONCLUSIONS Exercise-based cardiac rehabilitation is effective in reducing cardiac deaths .
It is not clear from this review whether exercise only or a comprehensive cardiac rehabilitation intervention is more beneficial .