In the first study, researchers looked at whether prayer on behalf of a patient could assist recovery from bypass surgery. A third of the patients were prayed for after being told that this might or might not be done; a third did not receive prayer; and a third received prayer after being told this would occur. The researchers concluded that prayer had no effect on complication-free recovery from bypass.
In the second study, researchers randomly assigned patients to one of four groups before elective cardiac catheterization and angiography. One group received standard care. The others, in addition to standard care, received either prayer or music, imagery, and touch (MIT) therapy; or both prayer and MIT therapy. MIT therapy included instruction in meditation and deep breathing, and the application of “healing touch” hand positions by trained practitioners. The investigators found that neither prayer nor MIT therapy was beneficial in preventing subsequent heart problems.
However, patients who received MIT therapy experienced a clear decrease in anxiety and distress before the catheterization—and were less likely to die during the subsequent six months. It's clear that the prayer didn't help. But whether it was the music, imagery, or touch that might have helped remains uncertain. Source.