The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee.

INTRODUCTION: The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications. METHODS: The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar. RESULTS: Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated. CONCLUSIONS: Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.

Determining the Feasibility of Spinal Cord Neuromodulation for the Treatment of Chronic Systolic Heart Failure: The DEFEAT-HF Study.

OBJECTIVES: The primary objective of the study was a change in left ventricular end-systolic volume index (LVESVi) from baseline to 6 months of spinal cord stimulation (SCS) therapy in the treatment arm compared to the control arm as measured by echocardiography. Secondary objectives were changes in peak oxygen uptake and N-terminal pro-B-type natriuretic peptide (NT-proBNP) between the treatment arm and control arm from baseline through 6 months. BACKGROUND: Abnormal neurohormonal activation is often responsible for progression of heart failure (HF). Treatment has often included drug therapy to modulate the neurohormonal axis. The purpose of the DEFEAT-HF (Determining the Feasibility of Spinal Cord Neuromodulation for the Treatment of Chronic Heart Failure) clinical study was to evaluate whether direct modulation of the nervous system through SCS improved HF metrics, including heart size, biomarkers, functional capacity, and symptoms. METHODS: The DEFEAT-HF study was a prospective, multicenter randomized (3:2), parallel, single-blind, controlled study to investigate whether SCS was a feasible therapy for the treatment of systolic HF for patients with New York Heart Association functional class III HF, left ventricular ejection fraction (LVEF) ≤35%, QRS duration <120 ms, and left ventricular end-diastolic dimension ≥55 mm. The primary objective of the DEFEAT-HF study was to evaluate the reduction in LVESVi after 6 months of SCS therapy in the treatment arm compared to the control arm. RESULTS: In total, 81 patients were enrolled, with 66 successfully randomized and implanted with the SCS device system. Seventy-six percent (50 of 66) had an implantable cardioverter-defibrillator at the baseline visit. Among randomized patients, the mean age was 61 years, 79% were male, mean LVEF was 27%, and mean QRS duration was 105 ms. The change in LVESVi over 6 months was not significantly different between randomization arms (SCS OFF: -2.2 [95% confidence interval: -9.1 to 4.6] vs. SCS ON: 2.1 [95% confidence interval: -2.7 to 6.9]; p = 0.30). Analyses of secondary endpoints for the study were also not significantly different. CONCLUSIONS: The present study does not provide evidence to support a meaningful change in clinical outcomes for HF patients receiving SCS. (Determining the Feasibility of Spinal Cord Neuromodulation for the Treatment of Chronic Heart Failure [DEFEAT-HF]; NCT01112579).