title: Effect of spinal cord stimulation on myocardial perfusion reserve in patients with refractory angina pectoris.
abstract: OBJECTIVE
  Epidural spinal cord stimulation (SCS) provides symptom relief in refractory angina pectoris, but its mechanism of action remains incompletely understood. We studied effects of short-term SCS therapy on myocardial ischaemia tolerance, myocardial perfusion reserve (MPR), and endothelium-mediated vasodilatation induced by cold pressor test (CPT) in patients with refractory angina pectoris.
  
  
  RESULTS
  We prospectively recruited 18 patients with refractory angina pectoris and studied them after implantation of SCS device at baseline before starting the therapy and after 3 weeks of continuous SCS therapy. Myocardial ischaemia was evaluated by dobutamine stress echocardiography. Global and regional myocardial blood flow (MBF) were measured using positron emission tomography and (15)O-water at rest, during adenosine stress, and in response to CPT. Systemic haemodynamics were comparable before and after 3 weeks of SCS at rest, during adenosine stress and during CPT. Appearance of angina pectoris induced by dobutamine stress was delayed after SCS therapy. Global MPR increased (P = 0.02) from 1.7 ± 0.6 at baseline to 2.0 ± 0.6 after 3-week SCS therapy. This was associated with a significant reduction in global MBF at rest and increase in MBF induced by adenosine in the ischaemic regions. Global MBF response to CPT was improved after SCS (0.27 ± 0.20 vs. 0.40 ± 0.15, P = 0.03).
  
  
  CONCLUSIONS
  Short-term SCS therapy improved myocardial ischaemia tolerance, absolute MPR, and endothelium-mediated vasomotor function in refractory angina pectoris, indicating that this therapy can alleviate myocardial perfusion abnormalities in advanced CAD.
authors.affiliation: Turku PET Centre, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, Turku FI-20520, Finland Heart Center, Turku University Hospital and University of Turku, Turku, Finland antsaras@utu.fi.
authors.forename: Antti
authors.initials: A
authors.lastname: Saraste
authors.affiliation: Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Ukkonen
authors.affiliation: Turku PET Centre, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, Turku FI-20520, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Varis
authors.affiliation: Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Tuija
authors.initials: T
authors.lastname: Vasankari
authors.affiliation: Department of Anesthesiology, Turku University Hospital, Turku, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Tunturi
authors.affiliation: Department of Anesthesiology, Turku University Hospital, Turku, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Taittonen
authors.affiliation: Department of Anesthesiology, Turku University Hospital, Turku, Finland.
authors.forename: Pirkka
authors.initials: P
authors.lastname: Rautakorpi
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Turku University Hospital, Turku, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Luotolahti
authors.affiliation: Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: K E Juhani
authors.initials: KE
authors.lastname: Airaksinen
authors.affiliation: Turku PET Centre, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, Turku FI-20520, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000368:Aged; D060050:Angina, Stable / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D015992:Body Mass Index; D001026:Coronary Artery Bypass / Q000379:methods; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D053805:Fractional Flow Reserve, Myocardial; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011788:Quality of Life; D012680:Sensitivity and Specificity; D062187:Spinal Cord Stimulation; D016896:Treatment Outcome
keywords: Angina pectoris; Coronary flow reserve; Myocardial blood flow; Positron emission tomography; Spinal cord stimulation