Acupuncture for Relief of Angina
To the Editor:
I read with interest the ESBY study (Electrical Stimulation versus coronary artery BYpass surgery in severe angina pectoris) by Mannheimer et al.1 They found that spinal cord stimulation (SCS) has antianginal and anti-ischemic effects in severe angina pectoris and concluded that CABG and SCS are equivalent methods in terms of symptom relief.
In a previous report,2 these authors showed that myocardial extraction of β-endorphin during control atrial pacing changed to release at the maximum pacing rate during SCS. Furthermore, their results indicate local myocardial turnover of β-endorphin, leuenkephalin, and calcitonin-gene–related peptide. Han et al3 found that electroacupuncture of different frequencies was able to activate different opioid systems in the spinal cord of the rat: low frequency (2 Hz) for [Met5 ]enkephalin release and high frequency (100 Hz) for dynorphin A release. An optimal combination of electroacupuncture parameters is now under study for maximal release of endogenous opioids in the central nervous system.
Mannheimer et al1 stated that it was not possible to blind their study to either patient or physician because the surgical procedures differ significantly. But acupuncture, which has the same effect as SCS3 and has been used in China for >2000 years as a therapy for various painful conditions, including severe angina pectoris,4 5 6 can be blinded to a large extent.
It is extremely gratifying to note that the age-old acupuncture therapy for angina relief now has scientific documentation of its modus operandi. Acupuncture therapy will not only be more cost-effective than either SCS or CABG but will also be completely benign in terms of morbidity or mortality. Much more research is warranted in this field.
- Copyright © 1998 by American Heart Association
Mannheimer C, Eliasson T, Augustinsson L-E, Blomstrand C, Emanuelsson H, Larsson S, Norrsell H, Hjalmarsson Å. Electrical stimulation versus coronary artery bypass surgery in severe angina pectoris: the ESBY study. Circulation. 1998;97:1157–1163.
Eliasson T, Mannheimer C, Waagstein F, Andersson B, Bergh C-H, Augustinsson L-E, Hedner T, Larson G. Myocardial turnover of endogenous opioids and calcitonin-gene-related peptide in the human heart and the effects of spinal cord stimulation on pacing-induced angina pectoris. Cardiology. 1998;89:170–177.
Han JS. Physiologic and neurochemical basis of acupuncture analgesia. In: Cheng TO. The International Textbook of Cardiology. Elmsford, New York: Pergamon Press; 1987:1124–1132.
Zhou XQ, Liu JX. Metrological analysis for efficacy of acupuncture on angina pectoris. Chung Kuo Chung Hsi I Chieh Ho Tsa Chih. 1993;13:212–214.
Kraemer ES, Cardoso M de FL, Yamamura Y. Acupuncture in angina pectoris. J Intern Med. 1991;229:383. Letter.
We thank Dr Cheng for his interesting comments on our study.
Despite some attempts to perform “blind” studies with acupuncture, we are not aware of any satisfactory way to achieve this.R1 R2 R3 We could not find any method to make a proper blinding in the ESBY study. Our group has tried acupuncture previously in patients with angina pectoris. There are some studies that may indicate an anti-ischemic effect of acupuncture on myocardial ischemia with only partial effect in humans.R1 R3 In contrast, the effect of SCS on myocardial ischemia is well documented in several reports from different centers. It has also been shown that myocardial ischemia creates anginal pain during stimulation and thus does not deprive patients of a warning signal.R4 Furthermore, according to our experiences, acupuncture is an unpractical method in this patient group.
Acupuncture is an afferent stimulation technique that is not comparable to SCS. SCS is a standardized central nervous system stimulation with well-defined, completely reproducible parameters.
However, we find further research in the field of acupuncture and ischemic heart disease of utmost importance, eg, the study by Li et al published this year in Circulation.R5
Richter A, Herlitz J, Hjalmarson Å. Effect of acupuncture in patients with angina pectoris. Eur Heart J. 1991;12:175–178.
Mannheimer C, Eliasson T, Andersson B, Bergh CH, Augustinsson LE, Emanuelsson H, Waagstein F. Effects of spinal cord stimulation in angina pectoris induced by pacing and possible mechanisms of action. BMJ. 1993;307:477–480.
Li P, Pitsillides K, Rendig S, Pan HL, Longhurst JC. Reversal of reflex-induced myocardial ischemia by median nerve stimulation: a feline model of electroacupuncture. Circulation. 1998;97:1186–1194.