Efficacy of spinal cord stimulation as an adjunct therapy for chronic refractory angina pectoris.
BACKGROUND
Patients with chronic refractory angina whose symptoms are not controlled with conventional therapies have a poor quality of life. Adjunctive therapies, such as spinal cord stimulation (SCS) may be considered in these cases. We sought to examine whether SCS is associated with changes in exercise capacity and angina severity in these patients.


METHODS
We searched Pubmed, Medline and other databases until December 2015. Two reviewers independently extracted data and assessed risk of bias. Exercise capacity included exercise duration and rate pressure product, determined via an exercise test. Angina severity included daily angina frequency and nitrate consumption.


RESULTS
A total of 518 participants (1048.25 person-years of follow-up), from 14 studies met our inclusion criteria. The mean age was 66.8years and 68.5% were men. SCS implant duration ranged from 3weeks to 5years (median: 6months). Using random effects meta-analysis, we found that SCS was associated with a higher exercise duration (1.90min, 95% CI 1.71, 2.06) and lower angina severity, 1.55 less daily angina episodes, (95% CI -1.75, -1.33), 1.54 less daily nitrates consumed, (95% CI -1.81, -1.26), and a 22 points higher SF-36 angina frequency score (95% CI 10.76, 32.81; p<0.0001) on follow-up. The change in rate pressure product was not significant.


CONCLUSIONS
This meta-analysis suggests that SCS, as an adjunct therapy to medical management, may be associated with a longer exercise duration and lower angina frequency and nitrate consumption in patients with chronic refractory angina pectoris who are not candidates for percutaneous intervention or revascularization.
Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States. Electronic address: TFImran@partners.org.
Tasnim F
TF
Imran
Brigham and Women's Hospital, Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States.
Raymond
R
Malapero
Icahn School of Medicine at Mount Sinai, 1428 Madison Ave., New York, NY 10029, United States.
Ahmed H
AH
Qavi
Eastern Virginia Medical School, 700 W Olney Road, Norfolk, VA 23507, United States.
Zachariah
Z
Hasan
Rutgers University, 77 Hamilton St., New Brunswick, NJ 08901, United States.
Bryan
B
de la Torre
Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States.
Yash R
YR
Patel
Brigham and Women's Hospital, Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States.
R Jason
RJ
Yong
Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States.
Luc
L
Djousse
Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States.
J Michael
JM
Gaziano
Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, 75 Francis St., Boston, MA 02120, United States.
Marie-Denise
MD
Gerhard-Herman
D000368:Aged; D000787:Angina Pectoris / Q000175:diagnosis* / Q000401:mortality / Q000523:psychology / Q000628:therapy*; D002908:Chronic Disease; D003131:Combined Modality Therapy; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000627:therapeutic use*; D010147:Pain Measurement; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012720:Severity of Illness Index; D062187:Spinal Cord Stimulation / Q000379:methods*; D016896:Treatment Outcome
D005996:Nitroglycerin
Chronic refractory angina pectoris; Myocardial ischemia; Nerve stimulation; Spinal cord stimulation