Acupuncture in angina pectoris: do psycho-social and neurophysiological factors relate to the effect?

We studied the effect of acupuncture in 49 patients with angina pectoris with focus on its relationship to psycho-social factors and changes in skin temperature, pain thresholds, and pain tolerance thresholds. No significant influence from patient expectation, social stress (strain) or profiles of the Minnesota Multiphasic Personality Inventory (MMPI) was found (all p > 0.1). Acupuncture slightly increased exercise tolerance (median 7%), the difference in Systolic Blood Pressure-Heart Rate Product between rest and maximal exercise (delta PRP) (median 3%), and the time to onset of pain (median 10%); decreased nitroglycerin consumption (median 58%) and anginal attack rate (median 38%). Improvement in exercise tolerance was significantly correlated to an improvement in delta PRP (correlation coefficient = 0.7; p < 0.0001) but not to time of myocardial ischemia (correlation coefficient = 0.1; p = 0.1). Compared with 28 patients with a less pronounced anti-anginal effect, the 21 patients with a pronounced effect had a significant increase in local skin temperature, but had no significant change in distant skin temperature and pain thresholds. It is concluded that acupuncture, due to hemodynamic alterations, might have a specific effect on angina pectoris in addition to drug treatments.