Why are acute ischemic stroke patients not receiving IV tPA? Results from a national registry

Objective: To determine patient and hospital characteristics associated with not providing IV tissue plasminogen activator (tPA) to eligible patients with acute ischemic stroke (AIS) in clinical practice. Methods: We performed a retrospective cohort study of patients with AIS arriving within 2 hours of onset to hospitals participating in Get With The Guidelines-Stroke without documented contraindications to IV tPA from April 2003 through December 2011, comparing those who received tPA to those who did not. Multivariable generalized estimating equation logistic regression modeling identified factors associated with not receiving tPA. Results: Of 61,698 eligible patients with AIS presenting within 2 hours of onset (median age 73 years, 51% female, 74% non-Hispanic white, median NIH Stroke Scale score 11, interquartile range 6-18), 15,282 (25%) were not treated with tPA within 3 hours. Failure to give tPA decreased over time from 55% in 2003 to 2005 to 18% in 2010 to 2011 (p < 0.0001). After adjustment for all covariates, including stroke severity, factors associated with failure to treat included older age, female sex, nonwhite race, diabetes mellitus, prior stroke, atrial fibrillation, prosthetic heart valve, NIH Stroke Scale score <5, arrival off-hours and not via emergency medical services, longer onset-to-arrival and door-to-CT times, earlier calendar year, and arrival at rural, nonteaching, non-stroke center hospitals located in the South or Midwest. Conclusions: Overall, about one-quarter of eligible patients with AIS presenting within 2 hours of stroke onset failed to receive tPA treatment. Thrombolysis has improved dramatically over time and is strongly associated with stroke center certification. Additionally, some groups, including older patients, milder strokes, women, and minorities, may be undertreated.