Among patients with an acute ischemic stroke treated with IV t-PA, those receiving antiplatelet therapy prior to the stroke had a higher risk for symptomatic intracranial hemorrhage but better functional outcomes than those who were not receiving antiplatelet therapy, according to a report published in the January issue of JAMA Neurology.
“This study represents the largest clinical experience of stroke thrombolysis in patients receiving antiplatelet therapy before stroke onset,” the study authors wrote. “The use of IV t-PA in patients receiving antiplatelet therapy was associated with a slight increased risk for symptomatic intracranial hemorrhage, especially among patients receiving aspirin or dual antiplatelet therapy. However, the relatively small excess risk did not translate into higher mortality and appeared to be associated with favorable functional outcomes at discharge. Therefore, the overall benefits of thrombolytic therapy may outweigh the risks in eligible patients with ischemic stroke receiving antiplatelet therapy before stroke onset.”
A Large, Nationwide Sample
In their observational study, lead author Ying Xian, MD, PhD, a fellow at Duke Clinical Research Institute in Durham, North Carolina, and colleagues used data from the American Heart Association and American Stroke Association’s Get With the Guidelines–Stroke registry to assess the risks and benefits associated with prestroke antiplatelet therapy. The registry included 85,072 adults with ischemic stroke who received IV t-PA in 1,545 registry hospitals from January 1, 2009, through March 31, 2015.
Main study outcomes included symptomatic intracranial hemorrhage, in-hospital mortality, discharge ambulatory status, and modified Rankin Scale score.
Patients receiving antiplatelet therapy (n = 38,844, 45.7% of the total cohort) were older and had a higher prevalence of cardiovascular risk factors than those not receiving antiplatelet therapy before admission for stroke (n = 46,228, 54.3% of the total cohort). The unadjusted rate of symptomatic intracranial hemorrhage was higher in patients receiving prestroke antiplatelet therapy (5.0% vs 3.7%). After risk adjustment, prior use of antiplatelet agents remained associated with higher odds of symptomatic intracranial hemorrhage, compared with no prior therapy (adjusted odds ratio, 1.18).
Among patients enrolled on October 1, 2012, or later, the highest odds of symptomatic intracranial hemorrhage were found in 15,116 patients receiving aspirin alone (adjusted odds ratio, 1.19) and 2,397 patients receiving aspirin and clopidogrel (adjusted odds ratio, 1.47). The adjusted risk for in-hospital mortality was similar between patients who were receiving prior antiplatelet therapy and those who were not. However, patients receiving antiplatelet therapy had a greater risk-adjusted likelihood of independent ambulation (46.6% vs 42.1%; adjusted odds ratio, 1.13) and better functional outcomes (ie, modified Rankin Scale score of 0 or 1) at discharge (27.8% vs 24.1%; adjusted odds ratio, 1.14).
In their analyses of secondary outcomes, the researchers found that the rates of life-threatening or serious symptomatic intracranial hemorrhage and any t-PA complications were higher in the patients receiving prior antiplatelet therapy. In the unadjusted analysis, fewer patients who received antiplatelet therapy were discharged home (41.4% vs 45.6%). However, they had higher adjusted odds ratios for being discharged home than patients without antiplatelet use (adjusted odds ratio, 1.13). No statistically significant differences were seen in discharge to hospice (unadjusted rates, 6.3% vs 4.6%; adjusted odds ratio, 0.97) or to a skilled nursing facility (unadjusted rates, 17.3% vs 13.9%; adjusted odds ratio, 0.98) between the groups.
Risk–Benefit Calculation
“Given the high prevalence of coronary artery disease and the widespread use of percutaneous coronary intervention, many patients are receiving aspirin or dual aspirin antiplatelet therapy at the time of stroke onset,” Dr. Xian and colleagues wrote. According to the researchers, their findings demonstrate that the risk for symptomatic intracranial hemorrhage among patients with stroke who receive antiplatelet therapy before the stroke and are treated with IV t-PA is relatively low and must be weighed against the potential benefits, in terms of improved functional outcomes. They concluded that improved functional outcomes in those receiving prestroke antiplatelet therapy outweigh the slightly increased risk of intracranial bleeding.
—Glenn S. Williams
