Modelling long-term outcomes in patients with post-stroke spasticity with or without BoNT-A treatment on all-cause mortality and secondary cardiovascular events: TOXINS 2024 7th International Conference: Basic science and clinical aspects of Botulinum and other neurotoxins - Berlin, Germany, 17/01/2024 - 20/01/2024.

App. 25 % of stroke survivors develop post-stroke spasticity (PSS) over the first year after a stroke, and they also experience motor weakness, which may prevent effective recovery by restricting mobility and participating in exercise programmes. Patients generally experience rapid improvement with Botulinum Toxin Type A (BoNT-A) therapy for PSS. Unfortunately, clinical trials demonstrating benefits from BoNT-A treatment are of short duration. Consequently, it is not known if treatment-related improvements in mobility could also contribute to lowering the risks of secondary cardiovascular (CV) events and all-cause death. To assess if BoNT-A injections could also have an impact on long-term outcomes, we developed a 10-year survival model comparing the effects of AbobotulinumtoxinA (aboBoNT-A) injections and rehabilitation therapy (aboBoNT-A+RT) with rehabilitation therapy (RT) alone. The Functional Independence Measure (FIM) appeared to be the only functional outcome allowing us to model the effect of aboBoNT-A injections on all-cause mortality. Stroke survivors who reported better improvement in FIM score during rehabilitation had lower risk of all-cause mortality during follow-up. Patients treated with aboBoNT-A injections + RT showed better improvement in FIM score than patients treated without aboBoNT-A injections. Our modelling results showed that the addition of aboBoNT-A injections to RT led to a reduction of 8.8 % in the risk of all-cause mortality, and a relative increase of 12.8 % in discounted life-years. The addition of aboBoNT-A injections to RT led to an increase in total costs of £42.329 over 10 years (based on National Health Service (NHS) UK cost collection 2018/2019). In the base-case scenario, incremental costs were driven by the increased number of hours of home care and RT for patients treated with aboBoNT-A injections compared with RT alone. Assuming an incremental cost-effectiveness ratio (ICER) threshold of £30.000, the probabilistic sensitivity analysis found a 73 % likelihood that aboBoNT-A + RT demonstrated cost-effectiveness compared with RT alone. Our work advocates for the need to consider and to capture the impact of BoNT-A injections on all-cause mortality and secondary events, such as CV events and recurrent stroke, which are prevalent in stroke survivors.