Subcutaneous electrical nerve stimulation: a feasible and new method for the treatment of patients with refractory...

Patients suffering from chronic angina pectoris, insufficiently controllable with medication and revascularization, are an increasing medical and psychosocial problem. Although spinal cord stimulation (SCS) is proven to employ, safe, long-term anti-angina, and anti-ischemic effects for these patients, the use of SCS in this group remains limited. The reason for this restricted use is largely unknown. However, among other reasons, it may be related to the difficulties in positioning an electrode in the epidural space. We studied the feasibility and efficacy of subcutaneous implantation of an entire system.

Seven male patients, mean age 67 ± 3.6 years, received complete subcutaneously implanted electrical nerve stimulation (SENS) systems, with one or more leads fixed in parallel with the sternum, covering the angina area. At baseline and 2 months follow-up patients performed exercise and quality of life tests (Seattle Angina Questionnaire and diaries number angina attacks and glyceryl trinitrate use).

All patients showed clinical relevant improvement (baseline vs. follow-up), in exercise (63%) and quality of life (Seattle Angina Questionnaire 59%). The number of angina attacks dropped 82% and the number of glyceryl trinitrate use decreased by 90%. No major adverse events were observed.

This small feasibility study demonstrates SENS to be an effective and safe method to treat patients suffering from refractory angina. Furthermore, SENS is less invasive and appears to have less lead migrations compared with SCS.