PMID- 15306747
OWN - NLM
STAT- MEDLINE
DCOM- 20050322
LR  - 20181113
IS  - 0929-5305 (Print)
IS  - 0929-5305 (Linking)
VI  - 17
IP  - 2
DP  - 2004 Apr
TI  - Establishing a new target range for unfractionated heparin for acute coronary 
      syndromes.
PG  - 121-6
AB  - INTRODUCTION: The target activated partial thromboplastin time (aPTT) range of 
      1.5 to 2.5 times the control value or 45 to 75 seconds recommended by the ACC/AHA 
      for patients receiving unfractionated heparin (UFH) for acute coronary syndromes 
      (ACS) is vulnerable to variation in test reagents. Rather than use the standard 
      target aPTT range, it has been recommended that each institution establish its 
      own target aPTT range based upon anti-factor Xa heparin levels. As a quality 
      assurance project, we evaluated our institution's therapeutic aPTT range by 
      examining the correlation between aPTTs and anti-factor Xa heparin levels and 
      established a new target aPTT range with a new thromboplastin reagent based upon 
      the therapeutic anti-factor Xa heparin levels. METHODS: Sixty-two plasma samples 
      from 26 consecutive patients receiving UFH for ACS were analyzed. Plasma aPTTs 
      measured with a thromboplastin reagent and a new thromboplastin reagent and 
      anti-factor Xa heparin levels were obtained on each plasma sample. Linear 
      regression analysis was performed to establish a new target aPTT range from 
      corresponding therapeutic anti-factor Xa heparin levels. RESULTS: Thirty-two 
      percent of patients with our institution's target range aPTTs of 61 to 100 
      seconds had anti-factor Xa heparin levels below 0.35 to 0.7 U/mL while 68% of 
      patients had therapeutic anti-factor Xa heparin levels (positive predictive value 
      = 68%). When the same blood was tested with a new thromboplastin reagent lot, 
      only 9% of patients with target range aPTTs had anti-factor Xa heparin levels 
      below 0.35 U/mL while 91% of patients had therapeutic anti-factor Xa heparin 
      levels (positive predictive value = 91%). The Pearson correlation coefficient ( r 
      ) for the new thromboplastin reagent lot was 0.93. The target aPTT range 
      established with the new thromboplastin reagent lot was 61 to 100 seconds. 
      CONCLUSION: Monitoring aPTTs without standardizing the thromboplastin reagent may 
      not adequately reflect therapeutic heparin levels. Despite apparently target 
      aPTTs, patients treated with UFH may be under-anticoagulated. Our new 
      anti-Xa-adjusted target aPTT range shows an increase in the positive predictive 
      value of aPTTs. Large-scale clinical studies are needed to determine the optimal 
      anti-factor Xa range for ACS patients treated with UFH, with further refinements 
      if glycoprotein IIb/IIIa inhibitors are concomitantly used and to show a benefit 
      in clinical outcomes for monitoring plasma heparin levels with anti-factor Xa 
      heparin levels. Institutional standardization of the aPTT is necessary to ensure 
      optimal patient care when changing thromboplastin reagents.
FAU - Lee, Michael S
AU  - Lee MS
AD  - St. Luke's-Roosevelt Hospital Center, Division of Cardiology, College of 
      Physicians and Surgeons, Columbia University, 1111 Amsterdam Avenue, New York 
      City, NY 10025, USA.
FAU - Menon, Venu
AU  - Menon V
FAU - Schappert, Joseph
AU  - Schappert J
FAU - Wilentz, James R
AU  - Wilentz JR
FAU - Singh, Varinder
AU  - Singh V
FAU - Hochman, Judith S
AU  - Hochman JS
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - J Thromb Thrombolysis
JT  - Journal of thrombosis and thrombolysis
JID - 9502018
RN  - 0 (Factor Xa Inhibitors)
RN  - 9005-49-6 (Heparin)
RN  - EC 3.4.21.6 (Factor Xa)
SB  - IM
MH  - Acute Disease
MH  - Aged
MH  - Aged, 80 and over
MH  - Coronary Artery Disease/*blood/drug therapy
MH  - Coronary Disease/*blood/drug therapy
MH  - Factor Xa/metabolism
MH  - Factor Xa Inhibitors
MH  - Female
MH  - Heparin/*blood/*therapeutic use
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Partial Thromboplastin Time/standards/*statistics & numerical data
MH  - Reference Values
MH  - Regression Analysis
EDAT- 2004/08/13 05:00
MHDA- 2005/03/23 09:00
CRDT- 2004/08/13 05:00
PHST- 2004/08/13 05:00 [pubmed]
PHST- 2005/03/23 09:00 [medline]
PHST- 2004/08/13 05:00 [entrez]
AID - 5273363 [pii]
AID - 10.1023/B:THRO.0000037667.52940.64 [doi]
PST - ppublish
SO  - J Thromb Thrombolysis. 2004 Apr;17(2):121-6. doi: 
      10.1023/B:THRO.0000037667.52940.64.