Long-term effects of electrical neurostimulation in patients with unstable angina: refractory to conventional therapies

Background.  Patients with unstable angina pectoris may become refractory to conventional therapies. Electrical neurostimulation with transcutaneous electrical stimulation and/or spinal cord stimulation has been shown to be effective for patients with refractory unstable angina pectoris in hospital settings. Our aim was to investigate the effects of electrical neurostimulation on outcomes of unstable angina after hospital discharge, in terms of hospital re-admission rates and long-term survival analysis. Method.  Twenty-seven consecutive patients with unstable angina pectoris, refractory to conventional therapies, received electrical neurostimulation in a tertiary referral hospital. We studied the number of hospital admissions in the year before when compared to the first year after electrical neurostimulation and performed survival analysis of the group. Results.  Twenty-six patients had beneficial effects of electrical neurostimulation during their admission to the hospital. During a mean follow-up of 6.6 ± 4.1 years, electrical neurostimulation was still effective in 21 out of 26. In 11 patients with previous hospital admissions, the number of hospital admissions decreased significantly after electrical neurostimulation (p = 0.007). The combined mortality and (re)infarction rate after one-year follow-up was 14%. Conclusion.  The results of this observational study show long-term beneficial effects of electrical neurostimulation in a population of patients with unstable refractory angina. Therefore, electrical neurostimulation should be considered as a beneficial treatment for patients with unstable angina pectoris, refractory to conventional therapies.