The learning curve for interventional cardiologists performing acute stroke interventions

Abstract Background Endovascular treatment for acute stroke because of large vessel occlusion became the standard of care in certain clinical settings. Due to lack of trainees and specialized centers, interventional cardiologists joined multidisciplinary stroke teams, and contribute their extensive knowledge on acute cardiovascular interventions and catheter skills to optimize patient management and outcomes. Purpose To investigate if a learning curve exists for interventional cardiologists performing acute stroke interventions. Methods Consecutive patients undergoing acute endovascular stroke treatment from 07/2012 – 10/2020 at our center were reviewed. The interventional approach, lesion preparation and material selection were at the discretion of the performing cardiologist. Baseline characteristics, procedural information and in-hospital outcomes were retrospectively collected. Cases were chronologically sorted, divided into quartiles and outcomes were compared. Results One-hundred-thirteen patients underwent endovascular procedures for acute stroke treatment. Patients were 72.9 SD 13.3 years old, and 51.5% were female. NIHSS at baseline was 15 [12–18]. In 92% the blood flow of the anterior circulation was affected. The door to needle (DTN) time decreased over time (Q1 1:19h [range0:54–1:58] vs. Q2 0:49h [range 0:34–1:32] vs. Q3 1:13h [range 0:56–1:31] vs. Q4 0:54 [range 0:37–1:08], p=0.003), as well as the procedure duration (time of vascular access to (full) reperfusion Q1 1:24h [range 0:44–2:23] vs. Q2 0:52h [range 0:32–1:16] vs. Q3 0:49h [range 0:27–1:15] vs. 0:44h [range 0:28–1:17], p=0.014) and the use of contrast medium (Q1 103.3mL [range 75.1–147.7] vs. Q2 123.5mL [range 60.5–149.9] vs. Q3 99.8mL [range 73–132] vs. Q4 74.8 mL [range 52.4–94.6], p=0.014). A stent retriever only strategy was preferred in the early stages (Q1 42.8% vs. Q2 53.5% vs. Q3 32.1% vs. Q4 17.2%. p=0.010), whereas a stent retriever plus aspiration strategy (Q1 17.8% vs. Q2 14.2% vs. Q3 28.5% vs. Q4 50%, p=0.122) became more popular later on. The combined quality endpoint comprising of TICI IIb/III flow after the procedure, no embolization to new territories and no symptomatic intracranial bleeding was reached 84%, with no difference between groups. Vascular access site complications were low (overall 3.5%) and NIHSS prior to discharge was comparable (Q1 3 [range 1.75–7.25] vs. Q2 4.5 [range 1.75–8.25] vs. Q3 5 [range 2–8] vs. Q4 4 [range 2–7], p=0.725). In-hospital death occurred in 21 (18.5%) patients. Conclusions A learning curve for interventional cardiologist performing acute stroke interventions could be observed in terms of optimized management strategies such as a reduced door to needle time and procedural aspects, like decreased procedure duration and contrast medium use over time. However, the quality of care was unaffected and continuously high. Funding Acknowledgement Type of funding sources: None.