An interesting study from duke university suggests that various forms of prayer did not help patients undergoing heart operations:

This study looked at 700 patients undergoing angiograms (an X-ray of the blood vessels) or other heart operations at nine hospitals across the US.

Christian, Muslim, Jewish and Buddhist prayer groups were assigned to pray for 371 of the patients. The rest had no prayer group.

In addition, 374 of the patients were assigned MIT therapy and the rest none.

MIT involved teaching the patients relaxed breathing techniques and playing them easy listening, classical, or country music during their procedure.

The researchers found that neither therapy alone, or combined, showed any measurable treatment effect on serious cardiovascular events, hospital readmission or death.

But those given music, imagery and touch therapy had less emotional distress and had a lower death rate after six months, though this was not seen as statistically significant.

("Prayer 'no aid to heart patients'", BBC, Jul.14)