Cocaine is a well-known precipitant of ischemic stroke1, 4
and there is concern cocaine may pose an enhanced risk for ICH after t-PA5
. While the safety of t-PA in the setting of CIS is unknown, the short time window to administer t-PA within three hours of AIS onset may make determining the presence of cocaine unfeasible. We report the largest series of patients with CIS to our knowledge and treated with t-PA and find that there were no events of sICH after t-PA. Compared with cocaine-negative patients who received t-PA, mortality was lower in the cocaine-positive t-PA treated patients; however, this difference was not statistically significant. Both cocaine-positive and cocaine-negative treated patients had similar outcomes at hospital discharge. Diastolic blood pressures were higher in the cocaine-positive group compared to the cocaine-negative group. However, all patients treated with t-PA met blood pressure AHA guidelines for thrombolysis and did not experience acute spikes in blood pressure during or after t-PA infusion. Moreover, despite having more severe deficits, patients with CIS who received t-PA did not have significant differences in sICH or mortality compared with those CIS patients who did not receive t-PA. Interestingly, it has been suggested that long-term cognitive impairment in cocaine users is the result of diffuse cerebral small vessel disease7
. Such patients might therefore be at increased risk for intracerebral hemorrhage; while we did find an increased incidence of small vessel disease in cocaine positive patients, we did not see an increased risk of sICH in this population.
This study has several limitations including its retrospective approach and small sample number. Although we report a large series of patients, this retrospective study is not powered to detect significant differences in sICH. Accordingly, the results must be interpreted with caution given that the outcomes of t-PA treated patients may be different if a substantially higher number of CIS patients were studied. There is a selection bias in designing a “cocaine-negative” patient group as not all patients on our stroke service undergo a toxicology screen, and older patients with vascular risk factors can have positive toxicology studies8
. Finally, the standard urine toxicology screen for the cocaine metabolite used at our hospital tests positive for three days after cocaine use. Therefore, this study does not rule out the possibility that acutely intoxicated patients may have a worse outcome after t-PA administration.
In conclusion, the results from this study suggest that t-PA may be safe to administer in CIS and that early outcomes after CIS do not appear to be adversely affected by t-PA. Often, in an emergency department setting, physicians do not know if a patient with AIS was using cocaine because the toxicology screen may not return in time to consider IV t-PA. We provide preliminary evidence that IV t-PA could be used in this patient population, but further studies are needed to more definitively determine the safety and efficacy of IV t-PA for CIS patients.