Severe angina pectoris and spinal cord stimulation. Long-term effects and safety aspects

Abstract

Refractory angina pectoris has been defined as coronary artery disease and severe angina, where standard pharmacological and invasive treatment possibilities are exhausted. The epidemiology of this condition is virtually unknown.During the last few decades, additional treatment options have evolved for this condition. Spinal cord stimulation (SCS) has been used since more than 15 years as additional symptom-relieving treatment for patients with severe angina pectoris. SCS has anti-ischemic effects and is safe and effective in clinical use. The extent of refractory angina pectoris among patients that had undergone coronary angiography was assessed in a defined geographic area, and the patients were characterised in terms of concurrent diseases, treatment, functional class, quality of life and the reasons for being considered inappropriate for revascularisation. Within two years, 100 patients were included. The mean age was 73 years, 26% were female and 59% of the patients had previously been subjected to revascularisation. In conclusion, there was a considerable number of patients with refractory angina, whose quality of life and functional status were severely impaired. However, rather few of these patients had congestive heart failure, renal dysfunction or pulmonary disease. The main reasons for rejection for revascularisation were unsuitable coronary anatomy and extracardiac diseases.The patients in the ESBY study (a randomised comparison of SCS and coronary artery bypass grafting (CABG) in 104 patients with severe angina and increased surgical risk) were followed up concerning long-term mortality, quality of life and cost-effectiveness. SCS as well as CABG turned out to offer these patients long-lasting improvement in quality of life, and the mortality was comparable with similar patient groups in other studies, and there were no differences between the two treatment groups. The health care costs were lower in the SCS group. Furtermore, there were no serious complications related to the SCS treatment. Eighteen patients with cardiac pacemaker as well as spinal cord stimulator were assessed concerning the safety of the combined treatment. A test procedure was performed and the patients were followed-up using a questionnaire. There was no interference between the two devices in any of the patients. A testing protocol for individual testing is proposed in the paper.The angina symptom changes were assessed in 32 patients with temporary cessation in long-term SCS treatment. There was a marked increase in symptoms during withheld treatment, which was promptly relieved after restitution of the SCS treatment.Conclusion Refractory angina was confirmed to be a considerable problem, where the average patient was younger and in a better general somatic condition than expected. Spinal cord stimulation, which is one of the treatment options for these patients, turned out to be safe (in terms of mortality, absence of serious complications and compatibility with cardiac pacemakers) and effective (in terms of symptom relief, quality of life and cost-effectiveness) during long-term treatment.