Similarly , there was no clear evidence of effect for cardiovascular risk factors , although again the number of studies reporting these was small .
There was some evidence for beneficial effects on HRQOL , dietary outcomes , and physical activity , although firm conclusions can not yet be made .
The effects on healthcare utilisation and cost-effectiveness are also inconclusive , and trials are yet to measure the impact of  Internet interventions on compliance with medication .
BACKGROUND The Internet could provide a means of delivering secondary prevention programmes to people with coronary heart disease ( CHD ) .
OBJECTIVES To determine the effectiveness of Internet-based interventions targeting lifestyle changes and medicines management for the secondary prevention of CHD .
An overview of randomized trials of rehabilitation with exercise after myocardial infarction.
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
Similarly , there was no clear evidence of effect for cardiovascular risk factors , although again the number of studies reporting these was small .
There was some evidence for beneficial effects on HRQOL , dietary outcomes , and physical activity , although firm conclusions can not yet be made .
The effects on healthcare utilisation and cost-effectiveness are also inconclusive , and trials are yet to measure the impact of  Internet interventions on compliance with medication .
BACKGROUND The Internet could provide a means of delivering secondary prevention programmes to people with coronary heart disease ( CHD ) .
OBJECTIVES To determine the effectiveness of Internet-based interventions targeting lifestyle changes and medicines management for the secondary prevention of CHD .