Reduced platelet activity is more common than reported anti-platelet medication use in patients with intracerebral hemorrhage

Andrew M. Naidech, Sarice L. Bassin, Richard A. Bernstein, H. Hunt Batjer, Mark J. Alberts, Paul F. Lindholm, Thomas P. Bleck

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Background: Anti-platelet medication and reduced platelet activity are associated with an increased risk of death after intracerebral hemorrhage (ICH). The optimal assay for assessing platelet activity is not defined. We hypothesized that reduced platelet activity would be common after ICH. Patients and Methods: We prospectively enrolled 72 consecutive patients with ICH and routinely measured platelet activity with both the PFA-100 (Siemens AG, Germany) and the VerifyNow-ASA (Accumetrics, CA, USA) systems on admission. We prospectively recorded anti-platelet medication use prior to ICH. Results: VerifyNow-ASA measurements were associated with aspirin (P = 0.001) and clopidogrel (P = 0.01) use prior to ICH. Combined clopidogrel and aspirin therapy was more potent than either alone. Of 33 patients with reduced platelet activity on the VerifyNow-ASA assay, 14 (42%) were not known to take anti-platelet agents. Of 27 patients with reduced platelet activity on the PFA-100, a related but different 14 (52%) were not known to take anti-platelet agents. There was a poor agreement between the assays (κ = 0.26, P = 0.07) on which patients had reduced platelet activity among the patients not known to take aspirin. Conclusions: A medication history does not reliably identify patients with reduced platelet activity after ICH, and this may explain studies that found no association between known aspirin use and outcomes. Future studies should screen for unknown use of anti-platelet medications after ICH. Neither assay perfectly identified patients who reportedly used anti-platelet medication before ICH.

Original languageEnglish (US)
Pages (from-to)307-310
Number of pages4
JournalNeurocritical Care
Volume11
Issue number3
DOIs
StatePublished - Jan 2009

Fingerprint

Cerebral Hemorrhage
Blood Platelets
clopidogrel
Aspirin
Germany

Keywords

  • Intracerebral hemorrhage
  • Platelets

ASJC Scopus subject areas

  • Clinical Neurology
  • Critical Care and Intensive Care Medicine

Cite this

Reduced platelet activity is more common than reported anti-platelet medication use in patients with intracerebral hemorrhage. / Naidech, Andrew M.; Bassin, Sarice L.; Bernstein, Richard A.; Batjer, H. Hunt; Alberts, Mark J.; Lindholm, Paul F.; Bleck, Thomas P.

In: Neurocritical Care, Vol. 11, No. 3, 01.2009, p. 307-310.

Research output: Contribution to journalArticle

Naidech, Andrew M. ; Bassin, Sarice L. ; Bernstein, Richard A. ; Batjer, H. Hunt ; Alberts, Mark J. ; Lindholm, Paul F. ; Bleck, Thomas P. / Reduced platelet activity is more common than reported anti-platelet medication use in patients with intracerebral hemorrhage. In: Neurocritical Care. 2009 ; Vol. 11, No. 3. pp. 307-310.
@article{ee498ecac954426995370a3e07cf041b,
title = "Reduced platelet activity is more common than reported anti-platelet medication use in patients with intracerebral hemorrhage",
abstract = "Background: Anti-platelet medication and reduced platelet activity are associated with an increased risk of death after intracerebral hemorrhage (ICH). The optimal assay for assessing platelet activity is not defined. We hypothesized that reduced platelet activity would be common after ICH. Patients and Methods: We prospectively enrolled 72 consecutive patients with ICH and routinely measured platelet activity with both the PFA-100 (Siemens AG, Germany) and the VerifyNow-ASA (Accumetrics, CA, USA) systems on admission. We prospectively recorded anti-platelet medication use prior to ICH. Results: VerifyNow-ASA measurements were associated with aspirin (P = 0.001) and clopidogrel (P = 0.01) use prior to ICH. Combined clopidogrel and aspirin therapy was more potent than either alone. Of 33 patients with reduced platelet activity on the VerifyNow-ASA assay, 14 (42{\%}) were not known to take anti-platelet agents. Of 27 patients with reduced platelet activity on the PFA-100, a related but different 14 (52{\%}) were not known to take anti-platelet agents. There was a poor agreement between the assays (κ = 0.26, P = 0.07) on which patients had reduced platelet activity among the patients not known to take aspirin. Conclusions: A medication history does not reliably identify patients with reduced platelet activity after ICH, and this may explain studies that found no association between known aspirin use and outcomes. Future studies should screen for unknown use of anti-platelet medications after ICH. Neither assay perfectly identified patients who reportedly used anti-platelet medication before ICH.",
keywords = "Intracerebral hemorrhage, Platelets",
author = "Naidech, {Andrew M.} and Bassin, {Sarice L.} and Bernstein, {Richard A.} and Batjer, {H. Hunt} and Alberts, {Mark J.} and Lindholm, {Paul F.} and Bleck, {Thomas P.}",
year = "2009",
month = "1",
doi = "10.1007/s12028-009-9219-7",
language = "English (US)",
volume = "11",
pages = "307--310",
journal = "Neurocritical Care",
issn = "1541-6933",
publisher = "Humana Press",
number = "3",

}

TY - JOUR

T1 - Reduced platelet activity is more common than reported anti-platelet medication use in patients with intracerebral hemorrhage

AU - Naidech, Andrew M.

AU - Bassin, Sarice L.

AU - Bernstein, Richard A.

AU - Batjer, H. Hunt

AU - Alberts, Mark J.

AU - Lindholm, Paul F.

AU - Bleck, Thomas P.

PY - 2009/1

Y1 - 2009/1

N2 - Background: Anti-platelet medication and reduced platelet activity are associated with an increased risk of death after intracerebral hemorrhage (ICH). The optimal assay for assessing platelet activity is not defined. We hypothesized that reduced platelet activity would be common after ICH. Patients and Methods: We prospectively enrolled 72 consecutive patients with ICH and routinely measured platelet activity with both the PFA-100 (Siemens AG, Germany) and the VerifyNow-ASA (Accumetrics, CA, USA) systems on admission. We prospectively recorded anti-platelet medication use prior to ICH. Results: VerifyNow-ASA measurements were associated with aspirin (P = 0.001) and clopidogrel (P = 0.01) use prior to ICH. Combined clopidogrel and aspirin therapy was more potent than either alone. Of 33 patients with reduced platelet activity on the VerifyNow-ASA assay, 14 (42%) were not known to take anti-platelet agents. Of 27 patients with reduced platelet activity on the PFA-100, a related but different 14 (52%) were not known to take anti-platelet agents. There was a poor agreement between the assays (κ = 0.26, P = 0.07) on which patients had reduced platelet activity among the patients not known to take aspirin. Conclusions: A medication history does not reliably identify patients with reduced platelet activity after ICH, and this may explain studies that found no association between known aspirin use and outcomes. Future studies should screen for unknown use of anti-platelet medications after ICH. Neither assay perfectly identified patients who reportedly used anti-platelet medication before ICH.

AB - Background: Anti-platelet medication and reduced platelet activity are associated with an increased risk of death after intracerebral hemorrhage (ICH). The optimal assay for assessing platelet activity is not defined. We hypothesized that reduced platelet activity would be common after ICH. Patients and Methods: We prospectively enrolled 72 consecutive patients with ICH and routinely measured platelet activity with both the PFA-100 (Siemens AG, Germany) and the VerifyNow-ASA (Accumetrics, CA, USA) systems on admission. We prospectively recorded anti-platelet medication use prior to ICH. Results: VerifyNow-ASA measurements were associated with aspirin (P = 0.001) and clopidogrel (P = 0.01) use prior to ICH. Combined clopidogrel and aspirin therapy was more potent than either alone. Of 33 patients with reduced platelet activity on the VerifyNow-ASA assay, 14 (42%) were not known to take anti-platelet agents. Of 27 patients with reduced platelet activity on the PFA-100, a related but different 14 (52%) were not known to take anti-platelet agents. There was a poor agreement between the assays (κ = 0.26, P = 0.07) on which patients had reduced platelet activity among the patients not known to take aspirin. Conclusions: A medication history does not reliably identify patients with reduced platelet activity after ICH, and this may explain studies that found no association between known aspirin use and outcomes. Future studies should screen for unknown use of anti-platelet medications after ICH. Neither assay perfectly identified patients who reportedly used anti-platelet medication before ICH.

KW - Intracerebral hemorrhage

KW - Platelets

UR - http://www.scopus.com/inward/record.url?scp=71949100304&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=71949100304&partnerID=8YFLogxK

U2 - 10.1007/s12028-009-9219-7

DO - 10.1007/s12028-009-9219-7

M3 - Article

C2 - 19381881

AN - SCOPUS:71949100304

VL - 11

SP - 307

EP - 310

JO - Neurocritical Care

JF - Neurocritical Care

SN - 1541-6933

IS - 3

ER -