CHICAGO – Traditional acupuncture improves heart rate variability, and it may prove to reduce the risk of sudden death for patients with established coronary heart disease, a pilot study suggests.
The blinded study with a sham-acupuncture control arm demonstrated that acupuncture accomplishes autonomic remodeling via sympathovagal modulation as reflected in increased heart rate variability (HRV), according to Dr. Puja K. Mehta of the Women's Heart Center at Cedars-Sinai Medical Center, Los Angeles. The clinically meaningful improvements in heart rate variability in this pilot study lay the groundwork for a future large outcome-based clinical trial of traditional acupuncture in patients with known CHD.
Diminished HRV in patients with CHD is accepted as a predictor of sudden cardiac death risk in clinical trials, Dr. Mehta noted at the annual meeting of the American College of Cardiology.
Sudden cardiac death accounts for roughly 150,000 deaths annually in Americans with established CHD. Traditional cardiovascular risk factors don’t fully account for the sudden cardiac death risk.
She reported on 151 patients with established CHD who were randomized to traditional acupuncture, sham acupuncture, or a wait-list control arm. The acupuncture, performed with stainless steel needles, was done three times per week for 12 weeks. Eight active CHD-specific traditional acupuncture sites were targeted. The sham-treatment group received a previously validated sham procedure at nonacupuncture sites. Patients were blinded as to whether they got real or sham acupuncture.
Heart rate variability was measured at baseline and after 12 weeks using 24-hour time and frequency domain measures and during a 5-minute mental arithmetic stress test and a 5-minute forehead cold pressor test.
Compared with the sham-treated controls, the traditional acupuncture recipients had 17% more high frequency HRV as determined by efferent vagal activity and 31% more heart rate variability on mental arithmetic stress testing at study’s end.
Dr. Mehta said that these results may actually underestimate the true clinical effect size of traditional acupuncture because sham acupuncture has previously been shown to have some mild therapeutic benefit compared with conventional placebos.
At study’s end, there were no differences between the acupuncture and sham control groups in blood pressure, serum lipids, insulin resistance, C-reactive protein, salivary cortisol, paroxysmal atrial tachyarrhythmia, or psychosocial variables, she noted.
The pilot study was supported by grants from the National Institutes of Health-National Center for Complementary and Alternative Medicine, the Barbara Streisand Women’s Cardiovascular Research and Education Program at Cedars-Sinai Medical Center, and foundation grants. Dr. Mehta reported having no financial conflicts.