# Large regional variation in endovascular thrombectomy rates for acute ischemic stroke in Sweden

## TL;DR

This study shows large regional differences in the use of endovascular thrombectomy for stroke treatment in Sweden, with improvements over time but still significant variation.

## Contribution

The paper introduces a new population success rate metric combining EVT rates and procedural effectiveness for evaluating stroke care implementation.

## Key findings

- EVT rates in Sweden increased from 4.1% to 7.3% between 2018 and 2022.
- There was a six-fold regional variation in EVT implementation across Sweden.
- Population success rate increased from 3.4% to 6.4% during the study period.

## Abstract

Endovascular thrombectomy (EVT) is a significant improvement in the care of acute ischemic stroke (AIS) patients, but only a small portion of patients receive treatment. Our aim was to analyze EVT implementation in Sweden according to a set of key performance indicators (KPIs) for procedural and implementational effectiveness.

A nationwide prospective registry-based observational study using data from 2018, 2020, and 2022 from the Swedish quality registries for stroke care (Riksstroke and EVAS) and official population statistics. Effectiveness was analyzed using a set of predefined KPIs. To describe procedural and implementation effectiveness in a single comprehensible measure population success rate was derived by multiplying the EVT rate with successful recanalization.

Between 2018 and 2022 EVTs in Sweden increased from 874 to 1474 procedures per year. Correspondingly, the EVT rate (EVT/AIS) increased from 4.1% to 7.3%. Implementation was heterogenous with a six-fold difference between the highest and lowest regions. EVT rates were generally highest in regions with comprehensive stroke centers (CSCs). Procedural effectiveness were similar between all CSCs. The population success-rate increased from 3.4% to 6.4% during the period with large differences between CSCs (range 3.4%–12.4%, in 2022).

By including KPIs for procedural and implementational effectiveness, it is possible to evaluate EVT implementation for the entire stroke population, which is the ultimate objective for healthcare. The population success-rate is capturing procedural implementation effectiveness in a single measure comprehensible for all stake holders and facilitate comparisons over time and between regions, even between regions with different stroke incidence.

Graphical abstract