Spinal Cord Stimulation for Heart Failure in the DEFEAT-HF Study: Lost Battle or Lasting Opportunities?

O ver the past few decades, pharmacological therapy for heart failure (HF) with reduced ejection fraction has undergone striking advances. Large-scale randomized, controlled trials (RCTs) have established the efficacy of combination therapy with beta-blockers, angiotensin-converting enzyme inhibitors or receptor blockers, aldosterone antagonists, and neprilysin inhibitors. Much of the benefit of these agents is mediated through their impact on the neurohormonal axis and modulation of autonomic tone. Consequently, there has been considerable interest in finding a nonpharmacological approach that is not vulnerable to the inconsistency of patient compliance or the side effects of pharmacotherapy. Spinal cord stimulation (SCS) is one such evolving strategy among a panoply of emerging device-based therapies seeking to exert neurohormonal control, such as vagal nerve, carotid baroreceptor, tragus nerve, and cardiac plexus stimulation. Among these, SCS enjoys the longest history of study in humans. Centered on the seminal work related to the gate control theory of pain by Melzack and Wall (2,3),