Comparison of Outcomes after Reperfusion Therapy between In-Hospital and Out-of-Hospital Stroke Patients

Background: Patients may experience stroke while being admitted to the hospital (in-hospital stroke (IHS)) and they may be important candidates for reperfusion therapy. IHS patients may have various comorbidities and show worse outcomes compared with patients with an out-of-hospital stroke (OHS). On the other hand, the time from onset to treatment may be shorter in IHS patients than OHS patients. Most outcome studies of reperfusion therapy have been based on findings in OHS patients, and little information is currently available regarding outcomes of IHS, whether the outcomes differ between patients with IHS and those with OHS who receive reperfusion therapy. Methods: This is a retrospective observational study using prospectively registered data. Consecutive patients who underwent the reperfusion therapy (intravenous (IV), intra-arterial (IA), or combined IV and IA) between July 2002 and June 2014 in a university hospital were included for this study. We compared the demographics, time interval from symptom onset to treatment, and outcomes between IHS and OHS patients and analyzed the factors associated with in-hospital mortality. Results: A total of 686 patients received the reperfusion therapy during the study period. Of them, 256 (37.3%) patients received the IV tissue plasminogen activator (t-PA) therapy only, 243 (35.4%) patients received the IA therapy only, and 187 (27.3%) patients received the combined IV and IA therapy. Among these, 104 (15.2%) were IHS patients. The time intervals from symptom onset to IV t-PA administration (87.5 ± 48.4 vs. 113.4 ± 38.3 min, p < 0.001) and IA puncture (221.8 ± 195.0 vs. 343.6 ± 155.4 min, p < 0.001) were shorter for IHS than OHS. The rates of successful recanalization and symptomatic intracerebral hemorrhage, and the favorable functional outcome at 3 months were similar between the groups. In-hospital all-cause mortality was higher in IHS than OHS (16.3 vs. 8.4%, p = 0.019), but after adjustment, IHS was not an independent factor. The stroke mortality did not differ between the groups (9.6 vs. 6.9%, p = 0.432). Conclusions: Although IHS patients more frequently had comorbid diseases and higher overall in-hospital mortality, the standard outcomes of the reperfusion therapy were similar between IHS and OHS patients, which might be, in part, ascribed to the shorter interval from symptom onset to treatment in IHS. Considering a substantial portion of IHS patients, we should pay more attention to these patients.