TY - JOUR
T1 - ECAP-controlled closed-loop versus open-loop SCS for the treatment of chronic pain
T2 - 36-month results of the EVOKE blinded randomized clinical trial
AU - Mekhail, Nagy A.
AU - Levy, Robert M.
AU - Deer, Timothy R.
AU - Kapural, Leonardo
AU - Li, Sean
AU - Amirdelfan, Kasra
AU - Pope, Jason E.
AU - Hunter, Corey W.
AU - Rosen, Steven M.
AU - Costandi, Shrif J.
AU - Falowski, Steven M.
AU - Burgher, Abram H.
AU - Gilmore, Christopher A.
AU - Qureshi, Farooq A.
AU - Staats, Peter S.
AU - Scowcroft, James
AU - McJunkin, Tory
AU - Carlson, Jonathan
AU - Kim, Christopher K.
AU - Yang, Michael I.
AU - Stauss, Thomas
AU - Petersen, Erika A.
AU - Hagedorn, Jonathan M.
AU - Rauck, Richard
AU - Kallewaard, Jan W.
AU - Baranidharan, Ganesan
AU - Taylor, Rod S.
AU - Poree, Lawrence
AU - Brounstein, Dan
AU - Duarte, Rui V.
AU - Gmel, Gerrit E.
AU - Gorman, Robert
AU - Gould, Ian
AU - Hanson, Erin
AU - Karantonis, Dean M.
AU - Khurram, Abeer
AU - Leitner, Angela
AU - Mugan, Dave
AU - Obradovic, Milan
AU - Ouyang, Zhonghua
AU - Parker, John
AU - Single, Peter
AU - Soliday, Nicole
N1 - Funding Information: This study was funded by Saluda Medical. Publisher Copyright: © American Society of Regional Anesthesia & Pain Medicine 2023. Re-use permitted under CC BY-NC. No commercial re-use. Published by BMJ.
PY - 2023
Y1 - 2023
N2 - Introduction: The evidence for spinal cord stimulation (SCS) has been criticized for the absence of blinded, parallel randomized controlled trials (RCTs) and limited evaluations of the long-term effects of SCS in RCTs. The aim of this study was to determine whether evoked compound action potential (ECAP)-controlled, closed-loop SCS (CL-SCS) is associated with better outcomes when compared with fixed-output, open-loop SCS (OL-SCS) 36 months following implant. Methods: The EVOKE study was a multicenter, participant-blinded, investigator-blinded, and outcome assessor-blinded, randomized, controlled, parallel-arm clinical trial that compared ECAP-controlled CL-SCS with fixed-output OL-SCS. Participants with chronic, intractable back and leg pain refractory to conservative therapy were enrolled between January 2017 and February 2018, with follow-up through 36 months. The primary outcome was a reduction of at least 50% in overall back and leg pain. Holistic treatment response, a composite outcome including pain intensity, physical and emotional functioning, sleep, and health-related quality of life, and objective neural activation was also assessed. Results: At 36 months, more CL-SCS than OL-SCS participants reported ≥50% reduction (CL-SCS=77.6%, OL-SCS=49.3%; difference: 28.4%, 95% CI 12.8% to 43.9%, p<0.001) and ≥80% reduction (CL-SCS=49.3%, OL-SCS=31.3%; difference: 17.9, 95% CI 1.6% to 34.2%, p=0.032) in overall back and leg pain intensity. Clinically meaningful improvements from baseline were observed at 36 months in both CL-SCS and OL-SCS groups in all other patient-reported outcomes with greater levels of improvement with CL-SCS. A greater proportion of patients with CL-SCS were holistic treatment responders at 36-month follow-up (44.8% vs 28.4%), with a greater cumulative responder score for CL-SCS patients. Greater neural activation and accuracy were observed with CL-SCS. There were no differences between CL-SCS and OL-SCS groups in adverse events. No explants due to loss of efficacy were observed in the CL-SCS group. Conclusion: This long-term evaluation with objective measurement of SCS therapy demonstrated that ECAP-controlled CL-SCS resulted in sustained, durable pain relief and superior holistic treatment response through 36 months. Greater neural activation and increased accuracy of therapy delivery were observed with ECAP-controlled CL-SCS than OL-SCS. Trial registration number: NCT02924129.
AB - Introduction: The evidence for spinal cord stimulation (SCS) has been criticized for the absence of blinded, parallel randomized controlled trials (RCTs) and limited evaluations of the long-term effects of SCS in RCTs. The aim of this study was to determine whether evoked compound action potential (ECAP)-controlled, closed-loop SCS (CL-SCS) is associated with better outcomes when compared with fixed-output, open-loop SCS (OL-SCS) 36 months following implant. Methods: The EVOKE study was a multicenter, participant-blinded, investigator-blinded, and outcome assessor-blinded, randomized, controlled, parallel-arm clinical trial that compared ECAP-controlled CL-SCS with fixed-output OL-SCS. Participants with chronic, intractable back and leg pain refractory to conservative therapy were enrolled between January 2017 and February 2018, with follow-up through 36 months. The primary outcome was a reduction of at least 50% in overall back and leg pain. Holistic treatment response, a composite outcome including pain intensity, physical and emotional functioning, sleep, and health-related quality of life, and objective neural activation was also assessed. Results: At 36 months, more CL-SCS than OL-SCS participants reported ≥50% reduction (CL-SCS=77.6%, OL-SCS=49.3%; difference: 28.4%, 95% CI 12.8% to 43.9%, p<0.001) and ≥80% reduction (CL-SCS=49.3%, OL-SCS=31.3%; difference: 17.9, 95% CI 1.6% to 34.2%, p=0.032) in overall back and leg pain intensity. Clinically meaningful improvements from baseline were observed at 36 months in both CL-SCS and OL-SCS groups in all other patient-reported outcomes with greater levels of improvement with CL-SCS. A greater proportion of patients with CL-SCS were holistic treatment responders at 36-month follow-up (44.8% vs 28.4%), with a greater cumulative responder score for CL-SCS patients. Greater neural activation and accuracy were observed with CL-SCS. There were no differences between CL-SCS and OL-SCS groups in adverse events. No explants due to loss of efficacy were observed in the CL-SCS group. Conclusion: This long-term evaluation with objective measurement of SCS therapy demonstrated that ECAP-controlled CL-SCS resulted in sustained, durable pain relief and superior holistic treatment response through 36 months. Greater neural activation and increased accuracy of therapy delivery were observed with ECAP-controlled CL-SCS than OL-SCS. Trial registration number: NCT02924129.
KW - CHRONIC PAIN
KW - Neuromodulation
KW - Spinal Cord Stimulation
UR - http://www.scopus.com/inward/record.url?scp=85171335638&partnerID=8YFLogxK
U2 - https://doi.org/10.1136/rapm-2023-104751
DO - https://doi.org/10.1136/rapm-2023-104751
M3 - Article
C2 - 37640452
SN - 1098-7339
JO - Regional anesthesia and pain medicine
JF - Regional anesthesia and pain medicine
M1 - rapm-2023-104751
ER -