There is an observed gender disparity in thrombolytic use for treatment of acute ischemic stroke. Studies have shown women are less likely to receive IV rt-PA than men for reasons that are not entirely clear. In this interesting analysis from the Netherlands, investigators of the PRACTISE study looked at sex differences in the use of IV rt-PA. 

A total of 5515 patients were included in the study. Women were on average four years older than men. Fewer women presented to the emergency room within the 4 hour window (27% vs. 33%). In fact, onset to door time was on average 27 minutes longer in female patients. The authors found however, once patients do get to the hospital within the narrow treatment window women were treated just as often as men with IV rt-PA. Of the female patients, 41% were age 80 and above, whereas only 22% of the male patient population were in this age group. This suggests that within this cohort, more women are experiencing their first stroke at an older age compared to men because they are on average living longer than men.
In a meta-analysis of 18 studies published in 2009, the gender disparity in the use of IV rt-PA was clearly demonstrated. 

Women with acute stroke were consistently less likely to receive thrombolysis compared to men. If the difference truly lies in the timeliness of presentation, then the exact cause for this could be multi-factorial. It is be more difficult to tease out the factors contributing to the delay depending on the local conditions and population.