Background: Spinal cord stimulation has been used for many years in the treatment of refractory angina pectoris. Its anti-anginal and anti-ischemic effect has been well documented in several studies, but the long-term efficacy, safety and survival rate are not well known. The aim of this study was to carry out a retrospective analysis of a series of patients from the Italian Multicenter Registry, the data of which were collected in five centers, by means of a questionnaire.
Methods: One hundred and thirty patients (83 males, 47 females, mean age 74.8 +/- 9.8 years) were submitted to spinal cord stimulator implantation for refractory angina pectoris in the period 1988-1995 and controlled during a mean follow-up of 31.4 +/- 25.9 months. A previous myocardial infarction had already occurred in 69.3% of patients, whereas in 67.6% multivessel coronary artery disease was documented. A left ventricular dysfunction (ejection fraction < 0.40) was present in 34% of patients; bypass surgery and coronary angioplasty were performed in 49.6% and in 27% of patients respectively. In 96.3% of cases revascularization procedures were not advisable.
Results: A complete follow-up of 116 patients (89.2%) was available. The spinal cord stimulator induced a significant reduction in NYHA functional class from 2.5 +/- 1.2 to 1.5 +/- 0.9 (p < 0.01). During the follow-up 41 patients (35.3%) died, and in 14.2% a new acute myocardial infarction developed. The total percentage of minor spinal cord stimulation-related complications was 6.8%. No major complications occurred. The annual total mortality rate was 6.5%, whereas the cardiac mortality rate was 5%. Compared to the survivors, patients who died showed a higher incidence of left ventricular dysfunction, previous myocardial infarction and bypass surgery at implantation.
Conclusions: In our experience, spinal cord stimulation is an effective therapy in patients affected by refractory angina pectoris and who cannot undergo revascularization procedure. The complication rate is low, with the total and cardiac mortality showing a trend as that reported for patients with similar coronary disease.