Patient QI found no studies specific to art therapy and blood pressure, however this nursing school link has some good ideas for art therapy as treatment for stress and to encourage relaxation: http://www.nursingschools.net/blog/2011/01/100-excellent-art-therapy-exercises-for-your-mind-body-and-soul/
There are many studies which investigate music therapy for anxiety and stress but only a handful of studies that investigate the effect of music on blood pressure. A US group reviewed all of these studies to date and published their paper in 2012. They found that compared to those who did not receive music therapy, those who did receive music therapy had a significantly greater decrease in systolic blood pressure, a significantly greater decrease in diastolic blood pressure and a significantly greater decrease in heart rate.
In July 2013, Frontiers in Psychology published a paper showing that the members of a choir synchronize heart rates as well as breathing patterns. The Swedish group also found that music with more structure, such as slow chants led to better synchrony in heartbeats. This suggests that singing in a choir could be beneficial for lowering heart rate and blood pressure and confirms that chanting during meditation is also beneficial.
Most studies on movement and reduction of hypertension relate to dance aerobics. One study published by a Nigerian Hospital in 2012 investigated the effects of dance movement therapy in hypertensive patients. After four weeks of dance movement therapy, resting diastolic blood pressure, resting heart rate, maximum heart rate were all reduced in the dance therapy group compared to no change in the control group.