Clinical outcomes among stroke patients receiving tissue plasminogen activator therapy beyond the 3-hour time window

Tissue plasminogen activator therapy (t-PA) is associated with improved neurologic outcomes and reduced disability from ischemic stroke. The current guidelines stipulate that patients receive t-PA within 3 hours of symptom onset. However, actual practice patterns vary, and little is known about patient outcomes when t-PA is received outside of the recommended time window.

We examined mean length of hospital stay, t-PA-related complications, and in-hospital death by time of t-PA administration in North Carolina Stroke Care Collaborative (NCSCC) patients. The NCSCC includes 53 hospitals that enroll patients presenting with stroke-like symptoms. Of 40,907 patients enrolled between January 2005 and February 2010, 1070 (2.6%) received t-PA. Of these, 88.2% received t-PA within 3 hours of symptom onset ("early") and 30.3% received t-PA between 3 and 6 hours after symptom onset ("late").

Unadjusted mean length of stay (days) was longer among early patients (5.0 days; 95% confidence interval [CI], 4.7-5.3) than late patients (3.6 days; 95% CI, 3.1-4.2). t-PA-related complications were similar among early (7.0%; 55/781) and late patients (6.7%; 7/102; P = .89). The proportion of in-hospital deaths was similar among late (10.5%) and early patients (12.0%). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% CIs for the associations between late t-PA status and patient outcomes.

In models controlling for age, race, sex, arrival mode, and ambulatory status on admission, late t-PA was not associated with increased odds of complications or in-hospital deaths (OR, 0.89; 95% CI, 0.49-1.62). The risks and benefits of expansion of the t-PA time window in stroke patients merit further investigation.