RT Book, Section
A1 Middeldorp, Saskia
A1 Coppens, Michiel
A2 Kaushansky, Kenneth
A2 Levi, Marcel
SR Print(0)
ID 1148373371
T1 Hereditary Thrombophilia
T2 Williams Hematology Hemostasis and Thrombosis
YR 2017
FD 2017
PB McGraw-Hill Education
PP New York, NY
SN 9781260117080
LK accesscardiology.mhmedical.com/content.aspx?aid=1148373371
RD 2024/10/13
AB SUMMARYThrombophilia  refers  to  laboratory  abnormalities  that  increase  the  risk  of  venous  thromboembolism  (VTE).  Over  the  past  several  decades,  numerous  factors  have  been  identified.  The  most  prevalent  examples  of  hereditary  forms  of  thrombophilia  include  the  factor  V  Leiden  and  prothrombin  G20210A  mutations;  deficiencies  of  the  natural  anticoagulants  antithrombin,  protein  C,  and  protein  S;  persistently  elevated  levels  of  coagulation  factor  VIII;  and  mild  hyperhomocysteinemia.  Taken  together,  some  form  of  hereditary  thrombophilia  can  be  identified  in  more  than  50  percent  of  patients  with  VTE  who  are  without  obvious  reasons  for  VTE,  such  as  trauma  or  prolonged  stasis.  Moreover,  hereditary  thrombophilia  has  been  associated  with  arterial  cardiovascular  disease  and  obstetric  complications  such  as  (recurrent)  pregnancy  loss  and  preeclampsia.  The  high  yield  of  thrombophilia  testing  has  led  to  widespread  testing  for  these  abnormalities  in  patients.  Nevertheless,  thrombophilia  testing  remains  a  topic  of  ongoing  debate,  mostly  because  of  the  lack  of  evidence-based  therapeutic  consequences.  While  hereditary  thrombophilia  is  a  clear  risk  factor  for  a  first  VTE,  the  risk  for  recurrent  episodes  is  only  slightly  increased  compared  with  nonaffected  patients,  and  prolonged  anticoagulation  is  probably  not  warranted  unless  VTE  is  recurrent.  A  similar  lack  of  therapeutic  consequences  applies  to  patients  with  arterial  cardiovascular  disease  and  women  with  obstetric  complications.  Thrombophilia  testing  in  asymptomatic  relatives  of  patients  with  VTE  may  be  useful  in  families  with  antithrombin,  protein  C,  or  protein  S  deficiency,  or  for  siblings  of  patients  who  are  homozygous  for  factor  V  Leiden,  and  is  limited  to  women  who  intend  to  become  pregnant  or  who  would  like  to  use  oral  contraceptives.  Careful  counseling  with  knowledge  of  absolute  risks  helps  patients  to  make  an  informed  decision  in  which  their  own  preferences  can  be  taken  into  account.