Background & Purpose: There are scarce data regarding outcomes of AIS patients treated with IVT within 60 min from symptom onset (“golden hour”). We sought to compare outcomes between AIS patients treated within (OTT≤60 min) and outside (OTT: 61-270min) the “golden hour” [GH(+) & GH (-)] using a propensity score matching approach.
Methods: Patients were evaluated during a 12-year period in a large, international, prospective registry of IVT (SITS-EAST). They underwent serial NIHSS-score assessments at baseline, 2 hrs and 24 hrs following tPA-bolus. Clinical recovery (CR) at 2 and 24 hrs was defined as a reduction of ≥10 points in NIHSS-score compared with baseline, or a NIHSS-score of ≤3 at 2 and 24 hrs respectively. A relative reduction in NIHSS-score of ≥40% at 2 hrs was predictive of complete recanalization (CREC). sICH was defined using SITS-MOST criteria; 3-month favourable functional outcome (FFO) was defined as a mRS-score of 0-1. The two groups were matched for demographics, risk factors, baseline NIHSS, admission blood pressure and serum glucose.
Results: Out of 19.077 tPA-treated AIS patients, 71 patients in GH(+) group [mean age 67±13 years; median NIHSS-score 12 points (IQR 10); median onset to treatment time (OTT) 55min, (IQR 10)] were matched to 6882 patients in GH(-) group (mean age 67±12 years; median NIHSS-score 11 points (IQR 9); median OTT 155min (IQR 55)]. The two groups did not differ in any of the matched characteristics (p>0.1). GH(+) had significantly (p<0.05) higher rates of 2hr (31% vs. 12%) and 24hr (41% vs. 27%) CR, CREC (39% vs. 21%) and 3-month FFO (47% vs. 34%). The rates of sICH (0% vs. 2%) and 3-month mortality (9% vs. 13%) were similar (p>0.2) in the two groups. GH(+) was independently (p<0.05) associated with 2hr CR (OR:5.5; 95%CI: 2.6-12.0), 24hr CR (OR:2.0; 95%CI: 1.1-3.6), CREC (OR:2.4; 95%CI: 1.4-4.3), and 3-month FFO (OR:2.3; 95%CI: 1.3-4.1) in multivariable logistic regression analyses adjusting for potential confounders.
Conclusions: AIS patients treated with IVT within the GH have substantially higher odds of early CR and FFO. These findings highlight the potential of mobile stroke units to further improve AIS outcomes by increasing the rates of tPA delivery within the GH.