Spinal cord stimulation in chronic intractable angina pectoris: a randomized, controlled efficacy study.

BACKGROUND: Spinal cord stimulation is known to be a successful treatment for chronic intractable angina pectoris. Its effect may be anti-ischemic. It is uncertain if the clinical effect is partly caused by a placebo effect of surgery for implantation of a stimulator. In this study, clinical efficacy is investigated, together with a possible placebo effect. METHODS AND RESULTS: Efficacy of spinal cord stimulation as a treatment for chronic intractable angina pectoris was studied for 6 weeks in 13 treated patients and 12 control patients with chronic angina. Assessments were exercise capacity and ischemia, daily frequency of anginal attacks and nitrate tablet consumption, and quality of life (perceived quality of life and pain). Compared with control, exercise duration (P =.03) and time to angina (P =.01) increased; anginal attacks and sublingual nitrate consumption (P =.01) and ischemic episodes on 48-hour electrocardiogram (P =.04) decreased. ST-segment depression on the exercise electrocardiogram decreased at comparable workload (P =.01). Anginal attacks and consumption of sublingual nitrates decreased (P =.01), perceived quality of life increased (P =.03), and pain decreased (P =.01). CONCLUSIONS: Spinal cord stimulation is effective in chronic intractable angina pectoris, and its effect is exerted through anti-ischemic action. Efficacy is unlikely to be explained as a placebo effect from surgery.