By Nancy Walsh, Staff Writer, MedPage Today
Published: April 25, 2011
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
Heart failure patients may experience improvements in their quality of life and mood by participating in a tai chi exercise program, a randomized study suggested.
The small study of patients with chronic systolic heart failure found that disease-specific quality of life -- measured on the Minnesota Living with Heart Failure Questionnaire -- showed benefits among those who took tai chi, with scores falling from a median of 28 at baseline to 9 at 12 weeks, according to Gloria Y. Yeh, MD, of Harvard in Boston, and colleagues.
In contrast, quality of life scores for the HF patients in an education-only control group were 21 at baseline and 22 at week 12 (P=0.02), the researchers reported in the April 25 Archives of Internal Medicine.
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Explains that patients with heart failure may experience improvements in their quality of life and mood by taking part in a tai chi program.
Note that limitations of this study include lack of blinding and its short follow-up period.
As well, mood improved among the tai chi group as measured by the Profile of Mood States, decreasing from a baseline score of 10 to 4 after 12 weeks, compared with scores of among controls that stayed close to baseline levels at week 12 (P<0.001).
Tai chi, with its "gentle meditative exercise of flowing circular movements, balance and weight shifting, breathing techniques, visualization, and focused internal awareness," is increasingly being adopted for use in various medical contexts, Yeh and colleagues observed.
They postulated that tai chi could be particularly helpful for frail older patients with debilitating heart failure, because of its multiple effects including increasing strength, training of the extremities, and mild aerobic actions.
To explore this issue, the researchers enrolled 100 patients, between May 1, 2005, and September 30, 2008, randomizing them to hour-long classes twice weekly of tai chi or to educational modules designed by the Heart Failure Society of America.
Mean age was 67, mean left ventricular ejection fraction at study entry was 29%, and peak oxygen uptake was 13.5 mL/kg/min.
Most patients had New York Heart Association class II heart failure and were receiving a beta-blocker and an angiotensin-converting enzyme inhibitor.
Almost one-third of the patients had a history of depression and anxiety.
After 12 weeks, there were no differences between the groups in change in six-minute walk distance or in peak oxygen uptake.
There was, however, an increase in metabolic expenditure outside of the class in the tai chi group (323 versus 156, P=0.05).
Patients in the tai chi group also reported benefits on mood.
Those patients improved on the total mood disturbance subscale of the Profile of Mood States -- consisting of 65 single-word items rated on a five-point scale to indicate recent mood in six dimensions.
Patients in the tai chi group decreased from an overall baseline score of 10 to a score of 4, while those in the control group had scores of 18 at baseline and 17 at week 12 (P<0.001).
On the depression subscale of that rating tool, scores decreased from 2 to 0 in the tai chi group, and increased from 3 to 4 in the control group (P=0.004).
On the vigor subscale, the tai chi group increased from 8.5 to 9, while the controls fell from 8 to -2 (P<0.001).
Significant benefits also were seen in exercise self-efficacy (P<0.001).
In addition, post-hoc analyses showed benefits for tai chi in patients without implanted cardioverter-defibrillators (P=0.04), in those with class II and class III symptoms (P=0.01), and in patients whose heart failure was not ischemic (P=0.03).
There also were greater improvements in disease-specific quality of life among patients in the tai chi group who had higher baseline resting heart rate.
"One of the purported mechanisms of mind-body exercises, such as tai chi, is favorable modulation of the autonomic nervous system," the researchers explained.
This may help explain their post-hoc finding of greater benefits in patients with high resting heart rates, "and presumably more sympathetic nervous system overdrive," they suggested.
The researchers noted that the importance of patient quality of life in heart failure increasingly is being valued.
"We observed large, clinically significant changes in quality of life in this study, similar to or even greater than what has been seen with cardiac resynchronization therapy," they wrote.
The improvements in mood were "highly relevant," they said, emphasizing the close link between heart failure and depression.
Limitations of the study include lack of blinding and its short follow-up period.
Additionally, only a small proportion of the more than 500 patients who met inclusion criteria actually enrolled in the trial, producing a small sample size which could have introduced selection bias.
To minimize potential disappointment among the education-only group (which could have affected scores), tai chi classes were offered at the end of the follow-up period.
The investigators were also unable to provide a "definitive physiological mechanism for tai chi's effects."
Nonetheless, they argue, this study provides informative data from the first large-scale clinical trial of tai chi exercise in an HF population.
Future work should address the potential mechanisms of effect as well as how programs such as this could be implemented into community practice.
In an invited commentary, John R. Teerlink, MD, of the San Francisco Veterans Affairs Medical Center echoed the call for further research into mind-body approaches such as this for heart failure.
"Mind-body medicine holds tremendous potential to improve both functional capacity and health-related quality of life in patients with [heart failure]; it is time to give these therapies the studies they deserve," he wrote.
The study was supported by the National Center for Complementary and Alternative Medicine and the National Institutes of Health.
The authors and editorialist reported no financial disclosures.
Primary source: Archives of Internal Medicine
Source reference:
Yeh G, et al "Tai chi exercise in patients with chronic heart failure: a randomized clinical trial" Arch Intern Med 2011; 171: 750-757.
Additional source: Archives of Internal Medicine
Source reference:
Teerlink J "Mind or body: evaluating mind-body therapy efficacy in heart failure trials" Arch Intern Med 2011;171:758-759.
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