Abstract and Introduction
Abstract
Refractory angina represents an important clinical problem. Spinal cord stimulation (SCS) for refractory angina has been used for over two decades to improve pain and, thus, quality of life. This case series reports the clinical efficacy and safety profile of SCS.
We included patients who had a SCS device implanted between 2001 and 2015 following a rigorous selection process. Patients were prospectively followed. We performed a descriptive analysis and used paired t-test to evaluate the difference in Canadian Cardiovascular Society angina (CCS) class before and after SCS implant.
Of the 100 patients included, 89% were male, the mean age was 65.1 years and mean follow-up time was 53.6 months. The CCS class after SCS implant was statistically improved from before (p<0.05) and 88% of patients who gave feedback were very satisfied. Thirty-two patients died, 58% of those who had a documented cause of death, died from a non-cardiac cause.
This study shows the outcome of 14 years' experience of SCS implantation. The anginal symptoms had a statistically significant improvement and the satisfaction rate was higher than 90%. The complication rate is within the range reported in the literature. SCS seems to be an effective and safe treatment option for refractory angina.
Introduction
Spinal cord stimulation (SCS) therapy has been used for more than four decades in a variety of chronic pain conditions. The introduction of neurostimulation was a logical consequence of the 'gate-control' theory published in 1965.[1] According to this model, the activation of large afferent nerve fibres inhibits pain input mediated by small fibres into the dorsal horn of the spinal cord. The goal of SCS is to attenuate discomfort by provoking paraesthesia in the same area.
The European Society of Cardiology defines refractory angina as a chronic condition characterised by the presence of angina caused by coronary insufficiency in the presence of coronary artery disease, which cannot be controlled by a combination of medical therapy, angioplasty and coronary bypass surgery.[2] This condition represents an important clinical problem with an incidence of 100,000 new cases per year in Europe.[3] The presence of reversible myocardial ischaemia should be clinically established to be the cause of the symptoms. Chronic is defined as duration of more than three months.[4] Many of these patients have already had coronary surgery and percutaneous coronary interventions. These patients have reversible ischaemia yet the coronary vessels are not amenable to surgery or stenting. SCS for refractory angina has been used for over two decades. This treatment does not improve disease progression, but is used in a palliative mode, by improving the pain symptoms and quality of life. The detailed mechanisms of action of SCS for refractory angina are complex, as it may improve coronary perfusion, in addition to attenuating pain signals. Interestingly, the majority of the refractory angina patients have been diagnosed with this condition, but cannot be offered a good estimate of survival, as the prognosis is very variable.
The increasing success of traditional treatment methods to treat coronary events has led to an improvement in survival rate of these patients and, as a consequence, to an increase in the number of patients presenting with refractory angina.
Randomised-controlled trials[5–10] have shown an improvement in symptoms (daily angina attacks or Canadian Cardiovascular Society angina class) after the use of SCS. Most trials have also shown a statistically significant improvement in quality of life,[5,6,8,9] as pointed out by Tsigaridas et al. in their recent systematic review.[11]
The aim of this study was to assess the clinical improvement of our patients, as well as to evaluate the safety of SCS by analysing the complications, long-term survival, cause of death and satisfaction with treatment, in our centre.
Br J Cardiol. 2016;23(3):106-109. © 2016 Medinews (Cardiology) Limited
