Background: Benefit of endovascular treatment (EVT) for acute stroke has been demonstrated recently in several randomized clinical trials. This benefit is time-dependent and revascularization achieved at later times is associated with a poor risk-benefit ratio.
Hypothesis: Stroke Code systems based on a drip-and-ship model have been implemented worldwide to accelerate iv-tPA treatment. However, access to EVT in remote areas is hampered due to long distances and delays related to inter-hospital transfers.
Methods: We studied patients treated with EVT from a prospective multicenter population-based registry of acute stroke patients treated with reperfusion therapies (SONIIA) initiated in January 2011. Three groups were defined: (1) patients directly evaluated in comprehensive stroke centers (CSC) (n=895), (2) patients transferred from a remote hospital located less than 1 hour away from a CSC (n=191) and (3) patients transferred from a remote hospital located more than 1 hour away from a CSC (n=153). We compared population EVT rates (number of EVT/100000 inhabitants/year) and time from stroke onset to groin puncture between groups. The benefit of helicopter over ground transfer was evaluated in group 3.
Results: We found no differences between the three groups in baseline characteristics (age, vascular risk factors and stroke severity). 48% of patients in group 1, 60% in group 2 and 62% in group 3 received iv-tPA previously to EVT, with time from symptom onset to iv-tPA of 120 min, 110 min and 137 min respectively. Population EVT rates were 4-fold higher in group 1 (6.69 in group 1, 2.07 in group 2 and 1.68 in group 3). Time from symptom onset to EVT was longer in group 2 (322 min [255-445]) and group 3 (365 min [312-450]) compared to group 1 (243 min [175-404]) (p<0.001). Helicopter transfer was used in 24% of patients in group 3 and reduced the time to groin puncture in 35 minutes.
Conclusions: Accessibility to EVT in remote areas is hampered in comparison to areas depending directly on CSC. Time from symptom onset to EVT is 90-120 minutes longer in patients transferred from remote hospitals compared to patients directly evaluated in CSC. Based on these results, strategies to shorten inter-hospital transfer time or alternative mother-ship models should be considered.