Spinal Cord Stimulation for Refractory Angina Pectoris

• Spinal cord stimulation in the treatment of refractory angina pectoris: 25-year clinical experience at a single center
• Bridging Antiplatelet Therapy With Cangrelor in Spinal Cord Stimulator Trial and Implant for Patient With Refractory Angina: A Case Report
• Spinal Cord Stimulation for Refractory Angina Pectoris: Current Status and Future Perspectives, a Narrative Review
• Spinal cord stimulation for the symptomatic treatment of rigidity and painful spasm in a case of stiff person syndrome
• Refractory angina pectoris: a 20-year (2003-2022) bibliometric analysis
• Spinal cord stimulation for refractory pericarditis: a case report and a review of the mechanism of action
• Burst stimulation for refractory angina pectoris - A case report
• Novel Concepts in the Management of Angina in Coronary Artery Disease

Spinal cord stimulation (SCS) has emerged as a promising therapeutic option for managing Refractory Angina Pectoris, offering significant symptom relief and improved quality of life.

The proposed mechanisms for SCS in RAP include:

1. Neuromodulation: Alters pain perception by inhibiting nociceptive transmission in the spinal cord.

2. Ischemic Preconditioning: Improves microvascular blood flow and myocardial oxygen balance, potentially reducing ischemic episodes.

3. Autonomic Regulation: Enhances parasympathetic activity and reduces sympathetic tone, which can improve coronary perfusion.

SCS is indicated for patients with RAP who meet the following criteria:

- Persistent angina despite optimal pharmacological therapy, including nitrates, beta blockers, calcium channel blockers, and antiplatelet agents.

- Unsuitability for further revascularization (e.g., coronary artery bypass grafting or percutaneous coronary intervention).

- Severe impairment of quality of life due to angina symptoms.

1. Trial Period: A temporary electrode is implanted to assess the efficacy of SCS. This trial lasts 3–7 days.

2. Permanent Implantation: If the trial is successful (≥50% reduction in angina or improvement in quality of life), a permanent electrode and pulse generator are implanted.

Studies and meta-analyses have demonstrated the benefits of SCS for RAP:

- Reduction in Angina Episodes: SCS significantly reduces the frequency and severity of angina attacks.

- Improvement in Exercise Tolerance: Patients exhibit increased capacity to perform physical activities.

- Enhanced Quality of Life: SCS is associated with reduced hospital admissions and improved psychological well-being.

- Safety Profile: SCS has a favorable safety profile, with most complications being related to device implantation (e.g., infection, lead migration).

- Reduces reliance on high-dose opioids and other analgesics. - Non-pharmacological and reversible. - Provides symptomatic relief in a condition with limited treatment options.

- High initial cost of implantation. - Requirement for regular follow-ups and device maintenance. - Risk of complications such as infection, lead displacement, or inadequate pain relief.

Gazzeri et al. from San Giovanni-Addolorata Hospital, La Sapienza University of Rome, and Virgen de la Arrixaca University Clinical Hospital in a systematic literature review evaluated the clinical effectiveness, mechanism of action, and safety profile of Spinal Cord Stimulation for Refractory Angina Pectoris. Comprehensive searches were performed in PubMed, Scopus, and Web of Science for studies published between 1990 and 2023. Of 328 articles identified, 6 met the inclusion and exclusion criteria for final analysis. The included studies consistently demonstrated that SCS significantly reduces the frequency of anginal episodes and nitroglycerin use while improving exercise capacity and quality of life. Proposed mechanisms include modulation of pain signals via the gate control theory, enhancement of autonomic balance, and redistribution of myocardial perfusion. Novel stimulation modalities, including high-frequency, Burst, and Differential Target Multiplexed (DTM), show potential advantages in enhancing patient comfort and clinical outcomes. Nevertheless, long-term studies are necessary to validate these findings and establish the comparative efficacy of these advanced technologies. SCS is a safe and effective therapy for patients with RAP who are unsuitable for surgical interventions. Innovations in neurostimulation, including closed-loop systems and personalized treatment strategies have the potential to optimize outcomes further. Rigorous clinical trials are needed to consolidate the role of SCS as a cornerstone therapy for the management of RAP ¹⁾.

The review by Gazzeri et al. is an important contribution to understanding spinal cord stimulation for refractory angina pectoris, particularly in terms of summarizing clinical efficacy and future directions. However, limitations in methodology, sample size, and comparative analysis diminish its impact. Addressing these gaps through a more systematic approach and detailed exploration of long-term outcomes and emerging technologies would enhance the study's utility for clinicians and researchers.

A 48-year-old male patient with recurrent pericarditis, characterized by refractory angina-like pain and reduced left ventricular ejection fraction (LVEF). After 1 year of having a spinal cord stimulator implanted, the patient is free from pain and narcotics, with a reduction of 428 mg equivalent dose of morphine. The patient's LVEF increased from 40% to 45% without changes to his previous medical treatment. This is the first reported case of refractory pericarditis managed with spinal cord stimulation.

Recognizing improved pain management reduced narcotic usage, and improved LVEF in the patient following SCS is critical to paving the way toward a complete understanding of the mechanism of action of SCS. This case reveals the therapeutic potential of SCS for cardiovascular pathologies other than refractory angina pectoris ²⁾