title: Spinal cord stimulation for refractory angina pectoris: a retrospective analysis of efficacy and cost-benefit.
abstract: BACKGROUND
  Patients with refractory angina pectoris have severe symptoms despite optimal medication, but are not suitable for revascularisation. Spinal cord stimulation (SCS) has been used for treating refractory angina pectoris since 1985. The efficacy of SCS has been proven by randomised controlled trials and follow-up studies have shown that SCS is a safe treatment. The objective of the current study was to retrospectively analyse the clinical outcomes and cost-benefit of SCS in patients with refractory angina pectoris.
  
  
  METHODS
  Eighteen months after SCS implantation, the effects on Canadian Cardiovascular Society (CCS) functional level and acute symptom relief of 24 patients with permanent SCS were analysed by review of medical records. Nineteen of these 24 patients were able to report their anginal frequency, nitroglycerin consumption and subjective perception on physical activity and quality of life.
  
  
  RESULTS
  Angina frequency decreased from a median of 14.0 to 2.3 attacks/week (p < 0.01). Nitroglycerin intake decreased from a median of 27.5 to 1.5 doses/week (p < 0.01). Canadian Cardiovascular Society angina class improved from a median of three to two (p < 0.001). During a three-year period before SCS implantation, the hospitalisation rate and duration related to coronary artery disease increased progressively. The duration of hospitalisation increased from a median of three to 10 days/patient/year. In the year after SCS implantation the duration of hospitalisation decreased to a median of 0 day/patient/year (p < 0.001). The cost of hospital care due to coronary artery disease decreased significantly thereafter. The total cost of SCS procedure was recovered within 16 months after implantation, which is less than 40% of the device life span.
  
  
  CONCLUSIONS
  This retrospective study indicates that SCS treatment alleviates angina symptoms and improves quality of life. The treatment is also effective in preventing hospitalisations and saving costs in hospital care. A prospective study is warranted to confirm the current observations.
authors.affiliation: Section of Cardiology, Division of Internal Medicine, Karolinska Institutet Danderyd Hospital, S-182 88 Stockholm, Sweden. wei.yu@med.ds.sll.se
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.forename: Fikru
authors.initials: F
authors.lastname: Maru
authors.forename: Magnus
authors.initials: M
authors.lastname: Edner
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hellström
authors.forename: Thomas
authors.initials: T
authors.lastname: Kahan
authors.forename: Hans
authors.initials: H
authors.lastname: Persson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000000981:diagnostic imaging / Q000191:economics* / Q000601:surgery*; D017023:Coronary Angiography; D003329:Coronary Vasospasm / Q000000981:diagnostic imaging / Q000191:economics / Q000601:surgery; D003362:Cost-Benefit Analysis; D004599:Electric Stimulation Therapy / Q000191:economics*; D004567:Electrodes, Implanted / Q000191:economics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000627:therapeutic use; D010343:Patient Admission / Q000191:economics; D011788:Quality of Life; D012189:Retrospective Studies; D013116:Spinal Cord / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin