SAN DIEGO – Patients with chronic systolic heart failure who were enrolled in a 12-week tai chi program experienced significant improvements in quality of life, mood, and exercise self-efficacy, compared with patients who were enrolled in an education-only control group, results from a single center study showed.
Dr. Gloria Y. Yeh
“Exercise is a recognized important part of heart failure management,” Dr. Gloria Yeh said at the annual meeting of the Heart Failure Society of America. “The focus of prior studies has been on aerobic training, with some new and recent emphasis on strength training. Little, however, is known about the potential value of integrative mind-body movement therapies in this population.”
Tai chi is well suited for heart failure patients, she said, because the physical component “is low impact [and] nonstrenuous, and can easily be performed by the elderly or the more severely deconditioned patients, which may be important in enhancing exercise compliance and self-efficacy.” Reported cardiorespiratory benefits include an increase in peak oxygen uptake and ventilatory capacity, a decrease in blood pressure, and modulations of autonomic tone.
For the current study, Dr. Yeh and her associates at Beth Israel randomized 100 patients with systolic heart failure either to 12 weeks of tai chi classes that met twice weekly or to 12 weeks of an education class that met twice weekly. Testing at baseline, 6 weeks, and 12 weeks in both groups included questionnaires, functional tests, and cardiopulmonary exercise testing.
To be eligible for the trial, patients had to have a left ventricular ejection fraction of 40% or less, be on a stable medical regimen, and have New York Heart Association class I-III heart failure. Study exclusions included unstable angina, MI, cardiac surgery, or cardiac resynchronization therapy in the past 3 months, a history of cardiac arrest in the past 6 months, and unstable ventricular arrhythmia.
The primary outcome measures were quality of life based on the Minnesota Living With Heart Failure Questionnaire (MLHFQ) and exercise capacity based on the 6-minute walk test and peak oxygen consumption (VO2max). Secondary outcome measures included mood based on the Profile of Mood States (POMS), exercise, self-efficacy based on the Cardiac Exercise Self-Efficacy Instrument (CESEI), and serum B-type natriuretic peptide (BNP).
The tai chi class included five basic movements and warm-up exercises that emphasized relaxation, breathing, mind-body awareness, cardiovascular endurance, and a 45-minute videotape for home practice. The mean age of patients in this group was 68 years, and 56% were male.
The education class was led by a nurse practitioner and was based on published Heart Failure Society of America education modules that covered standard heart failure topics such as diet, activity, medications, heart arrhythmia problems, and advance care directives. The mean age of patients in this group was 67 years, and 72% were male.
Dr. Yeh reported that over the course of the 12-week study, 75% of participants in the tai chi group attended all classes, compared with 67% of participants in the education group. Tai chi group participants reported a mean of 10 hours of home practice over the study period.
At 12 weeks, patients in the tai chi group significantly improved their median MLHFQ scores by 19 points (from 28 at baseline to 9 at week 12), but there was no significant change in scores among those in the education group (21 points at baseline and 22 at 12 weeks). “This was quite a striking effect,” Dr. Yeh said.
For the 6-minute walk, patients in the tai chi improved their walk distance by 35 m (from 391 m at baseline to 426 m), a nonsignificant improvement, whereas patients in the education group improved their walk distance by just 2 m (from 392 m to 394 m).
Similarly, there was no significant difference in peak oxygen uptake between the two groups. In the education group, the VO2max dropped from 13.5 mL/kg per minute at baseline to 13 mL/kg per minute at week 12. In the tai chi group, the VO2max rose from 11.9 at baseline to 13 at week 12.
The researchers observed clinically and statistically significant improvements in the tai chi group, compared with the education group, in the POMS total mood disturbance score and in the CESEI score over the 12 weeks. However, there were no differences in serum BNP between the two groups over the course of the study.
“There may be several potential mechanisms for tai chi’s effect,” Dr. Yeh noted. “Observed effects may be due to the intervention’s physical activity and associated training effect. Tai chi includes mild to moderate aerobic exercise as well as upper and lower extremity and core strength training. Some benefits may be due to relaxation and stress reduction components of tai chi acting on stress-related neuromodulators. Similarly, mediation and mind-body integration may favorably affect autonomic tone, and breathing retraining may decrease perceived dyspnea.”