Is Platelet Response Test Status Associated with NIH Stroke Scale and Stroke Location?

OBJECTIVE: To determine if antiplatelet response is associated with stroke severity and location. BACKGROUND: Antiplatelet resistance is a controversial topic in acute stroke. However, physicians are utilizing this test to determine which antiplatelet to continue on stroke patients. Although a logical choice, it remains unclear whether switching patients from one antiplatelet to another after a negative platelet response test provides any added protection against another stroke. It remains unclear whether aspirin or Plavix resistance plays a factor in primary stroke severity as well as type of stroke or even stroke location.Potential clot morphology, composition, or size many be different in patients on antiplatelet therapy. It is unclear whether antiplatelet resistance could have a role in stroke severity and location.Therefore, a retrospective study was undertaken to review patients who presented with a stroke as confirmed by CT/MRI criteria, and compare antiplatelet response or resistance(of either aspirin or Plavix) and NIHSS as well as location/vascular territories involved. DESIGN/METHODS: A retrospective chart review of stroke patients from 1/2010 to 12/2011 was completed. Inclusion criteria included patients who presented with a stroke and were either on aspirin, plavix or both,who also had a platelet response test done upon admission. NIHSS was noted on admission, and neuroimaging data was reviewed regarding location and vascular distribution. RESULTS: A total of 381 patients were included in the study. The average NIHSS for aspirin responders was 5.53 vs 5.68 for the non-responders(p=0.91), but no statistically significant difference was noted. The average NIHSS for plavix responders was 4.185 versus 6.467 for non-responders, which was statistically significant(p=0.03). The vascular territories involved were compared as well. CONCLUSIONS: Antiplatelet use is widespread in cerebrovascular and cardiovascular disease. Clopidogrel resistance was associated with increased stroke severity. Although, prior studies showed a similar association with aspirin, our study did not. Disclosure: Dr. Mustafa has nothing to disclose. Dr. Kamal has nothing to disclose. Dr. Li has nothing to disclose. Dr. Ghazi has nothing to disclose. Dr. Beltagy has nothing to disclose. Dr. Mehta has received personal compensation for activities with Biogen Idec, Teva, and Gerson Lehrman Group as a consultant or speaker.