PMID- 23386070
OWN - NLM
STAT- MEDLINE
DCOM- 20130729
LR  - 20141120
IS  - 1542-6270 (Electronic)
IS  - 1060-0280 (Linking)
VI  - 47
IP  - 2
DP  - 2013 Feb
TI  - Discordant aPTT and anti-Xa values and outcomes in hospitalized patients treated 
      with intravenous unfractionated heparin.
PG  - 151-8
LID - 10.1345/aph.1R635 [doi]
AB  - BACKGROUND: Both the activated partial thromboplastin time (aPTT) and anti-Xa 
      assay can be used to monitor unfractionated heparin (UFH). Following 
      implementation of an anti-Xa method for heparin dosing protocols in our hospital, 
      we became aware of many patients with discordant aPTT and anti-Xa values. 
      OBJECTIVE: To determine the frequency of discordant aPTT and anti-Xa values in a 
      large cohort of hospitalized patients treated with UFH, as well as the 
      demographics, coagulation status, indication for UFH, and clinical outcomes in 
      this population. METHODS: All aPTT and anti-Xa values from adults hospitalized 
      between February and August 2009 at Stanford Hospital who were treated with UFH 
      were analyzed. All samples were drawn simultaneously. A polynomial fit 
      correlating aPTT and anti-Xa with a 99% confidence limit was designed. Paired 
      aPTT/anti-Xa values were grouped according to whether the paired values fell 
      within or outside of the concordant area. Patients were placed into groups based 
      on concordance status, and clinical outcomes were assessed. RESULTS: A total of 
      2321 paired values from 539 patients were studied; 42% of data pairs had a high 
      aPTT value relative to the anti-Xa value. Patients with elevated baseline 
      prothrombin time/international normalized ratio or aPTT frequently demonstrated 
      disproportionate relative prolongation of the aPTT. Patients with at least 2 
      consecutive high aPTT to anti-Xa values had increased 21-day major bleeding (9% 
      vs 3%; p = 0.0316) and 30-day mortality (14% dead vs 5% dead at 30 days; p = 
      0.0202) compared with patients with consistently concordant values. CONCLUSIONS: 
      aPTT and anti-Xa values are frequently discordant when used to measure UFH in 
      hospitalized patients. A disproportionate prolongation of the aPTT relative to 
      the anti-Xa was the most common discordant pattern in our study. Patients with 
      relatively high aPTT to anti-Xa values appear to be at increased risk of adverse 
      outcomes. Monitoring both aPTT and Xa values may have utility in managing such 
      patients.
FAU - Price, Elizabeth A
AU  - Price EA
AD  - Department of Medicine (Hematology), School of Medicine, Stanford University, 
      Stanford, CA, USA.
FAU - Jin, Jing
AU  - Jin J
FAU - Nguyen, Huong Marie
AU  - Nguyen HM
FAU - Krishnan, Gomathi
AU  - Krishnan G
FAU - Bowen, Raffick
AU  - Bowen R
FAU - Zehnder, James L
AU  - Zehnder JL
LA  - eng
PT  - Journal Article
DEP - 20130205
PL  - United States
TA  - Ann Pharmacother
JT  - The Annals of pharmacotherapy
JID - 9203131
RN  - 0 (Anticoagulants)
RN  - 0 (Antithrombins)
RN  - 9005-49-6 (Heparin)
SB  - IM
CIN - Ann Pharmacother. 2013 Sep;47(9):1239-40. PMID: 24259747
MH  - Aged
MH  - Anticoagulants/administration & dosage/*adverse effects/therapeutic use
MH  - Antithrombins/*blood
MH  - Blood Coagulation/*drug effects
MH  - California/epidemiology
MH  - Cohort Studies
MH  - Drug Monitoring/*methods
MH  - Female
MH  - Follow-Up Studies
MH  - Hemorrhage/*chemically induced/epidemiology/mortality/prevention & control
MH  - Heparin/administration & dosage/*adverse effects/therapeutic use
MH  - Hospitals, University
MH  - Humans
MH  - Infusions, Intravenous
MH  - Male
MH  - Middle Aged
MH  - Mortality
MH  - Partial Thromboplastin Time
MH  - Retrospective Studies
MH  - Risk
MH  - Secondary Prevention
MH  - Thrombosis/blood/epidemiology/mortality/*prevention & control
EDAT- 2013/02/07 06:00
MHDA- 2013/07/31 06:00
CRDT- 2013/02/07 06:00
PHST- 2013/02/07 06:00 [entrez]
PHST- 2013/02/07 06:00 [pubmed]
PHST- 2013/07/31 06:00 [medline]
AID - aph.1R635 [pii]
AID - 10.1345/aph.1R635 [doi]
PST - ppublish
SO  - Ann Pharmacother. 2013 Feb;47(2):151-8. doi: 10.1345/aph.1R635. Epub 2013 Feb 5.