Long-term Outcomes of Fast-acting Sub-perception SCS: Multinational, Real-world Analysis Across Europe and the United States

Introduction: Fast-Acting Sub-Perception Therapy (FAST-SCS) is a novel spinal cord stimulation modality that delivers rapid, paresthesia-free analgesia by re-engaging surround inhibition (SI) mechanisms. Unlike traditional high-frequency SCS, which exhibits delayed onset ("wash-in"), FAST-SCS elicits pain relief within seconds to minutes. This therapy uses biphasic-symmetric waveforms at sub-perception intensities that are empirically tuned to activate SI pathways disrupted in chronic pain states. Here, we report long-term clinical outcomes in patients using FAST-SCS across cohorts in both Europe and the United States, assessing pain relief durability, responder rates, and patient-reported outcomes up to 3-years follow-up.

Methods: To date, a total of 537 patients who preferentially utilized FAST-SCS for treatment of chronic pain have been observationally assessed across 12 centers in 7 countries in Europe and 7 sites in the United States. Patients were implanted with SCS Systems (Boston Scientific) capable of FAST-SCS programming per 90 Hz frequency, 210 ± 50 µs pulse width, and 30–40% perception threshold. Clinical measures evaluated include NRS pain score reduction, responder rate (≥50% pain relief). quality of life (EQ-5D-5L) and disability (Oswestry Disability Index).

Results: A majority of patients treated were identified to have an indication of lumbar radiculopathy and/or Persistent Spinal Pain Syndrome type 2. Among all patients, 119 have so far reached 24-months follow-up, while 61 patients have reached 36-months follow-up. Both of these subsets demonstrate a mean NRS pain score change from baseline of at least 5 points (range of mean baseline NRS: 7.2 - 7.9). Over 60% of the patients who reached the 24-month follow-up (n = 119) reported an NRS pain score of 2 or less. Of the patients who were assessed at 36-months (n = 61), just over 57% reported an NRS pain score of 2 or less. Additional data is currently undergoing collection and analysis. Updated data will be reported.

Conclusion: Across cohorts assessed in Europe and the United States, use of FAST-SCS was observed to provide long-term pain relief up to 36-months follow-up. This includes a substantial proportion who were noted to have minimal pain (NRS ≤ 2) at long-term follow-up (≥24-months). These findings validate FAST-SCS as a mechanism-driven therapeutic approach that can be successfully utilized amidst an assortment of patients across different clinical settings and geographies.