In addition to establishing safety, the results showed that Tai Chi was well liked by participants, who all said they would recommend it to a friend.

The exercise intervention was also proved feasible, with patients attending about 66 percent of scheduled classes. The results also showed that while Tai Chi did not raise aerobic fitness on standard tests after three months of either the programs, it did raise the weekly amount of moderate to vigorous physical activity after three and six months in the group participating in the longer program.

Salmoirago-Blotcher said in an email to Xinhua that there is a fair amount of literature supporting the benefit of Tai Chi for patients with heart disease.

For example, a recent meta-analysis published in 2016 showed that Tai Chi exercise can improve physical functioning, quality of life, depression, and blood pressure in patients with heart disease, she said. But Salmoirago-Blotcher noted that her study was only designed to study the feasibility and safety of Tai Chi, not the efficacy, as an exercise alternative for patients that don't attend cardiac rehabilitation.

A yoga practitioner, Salmoirago-Blotcher said she had tried Tai Chi herself to get a sense of how it feels before she designed this study and proposed it to her patients.

"On its own, Tai Chi wouldn't obviously replace other components of traditional cardiac rehabilitation, such as education on risk factors, diet and adherence to needed medications," she said.

"If proven effective in larger studies, it might be possible to offer it as an exercise option within a rehab center as a bridge to more strenuous exercise, or in a community setting with the educational components of rehab delivered outside of a medical setting," she said.