This study was retrospective in design so causality cannot be proven; however results demonstrate that renal insufficiency with GFR < 45 mL/min/1.73 m2 is an independent risk factor for long term poor outcome in patients who have received IV r-tPA and thereby might be considered as an important risk factor in future studies, in registrations, and even for developing associated guidelines. This evidence concerns the gene PLAT and Renal insufficiency.