ASH 2018: HIT Flashcards
If risk of HIT is low for patient receiving heparin, don’t do
Platelet count monitoring to screen for HIT
If risk of HIT is 0.1% - 100%, do
Platelet count monitoring to screen for HIT
For platelet count monitoring, when to start
A. If patient has had heparin in the 30 days prior
B. If patient is heparin naive
C. If patient is high risk (frequency)
D. If patient is intermediate risk (frequency)
A. Day 0
B. Day 4 - 14 or until heparin is stopped
C. Every other day
D. Every 2 - 3 days
If suspected HIT and 4T score shows intermediate or high probability, strong recommendation for
Immunoassay
If immunoassay is positive, conditional recommendation to follow up with a functional assay
If suspected HIT and low 4T score, don’t do (2 things)
- HIT laboratory testing
- Empiric HIT therapy
Strong recommendations
If suspected HIT and intermediate 4T score, regardless of whether or not they have an indication for therapeutic anticoagulation, strong recommendation to
Discontinue heparin
If suspected HIT, intermediate 4T score, no Other indication for therapeutic anticoagulation, conditional recommendation for (incl if high bleeding risk or no high bleeding risk)
Non-heparin anticoagulation at therapeutic dosing if not at high risk for bleeding
Non-heparin anticoagulation at prophylactic dosing if at high risk for bleeding
If suspected HIT, intermediate 4T score, and Another indication for therapeutic anticoagulation, conditional recommendation for
Therapeutic dosing of non-heparin anticoagulant
If suspected HIT, high 4T score, strong recommendation for
Discontinuation of heparin and initiation of non-heparin anticoagulant
If suspected HIT, high 4T score and negative immunoassay, strong recommendation to
Stop non-heparin anticoagulant and restart heparin
If suspected HIT, intermediate 4T score and positive immunoassay, strong recommendation to
Continue avoiding heparin
Administer therapeutic doses of non-heparin anticoagulant
In acute HITT (HIT + Thrombosis) or HIT patients, strong recommendation to
Discontinue heparin and start non-heparin anticoagulant
Preferred drugs for acute HIT if critical illness, increased bleed risk, life or limb threatening thromboembolism, or increased need for urgent procedures
Vs.
Reasonable options in clinically stable patients at average bleeding risks
Argatroban or Bivalirudin
Vs.
Fondaparinux or DOACs
If DOAC for acute HITT, most published option (with dose)
If acute, isolated HIT (with dose)
Rivaroxaban 15 mg BID x 3 weeks, then 20 mg daily
Rivaroxaban 15 mg BID until platelet count recovery, then 20 mg daily
Routine insertion of IVC filter in acute HIT or HITT?
No
When to start warfarin in acute HITT or HIT
After platelet count recovery (150 x 10^9)
If on warfarin and diagnosed with HIT or HITT
Stop warfarin, give vitamin K and start non-heparin anticoagulant
Routine platelet transfusion for acute HIT or HITT?
No
If acute isolated HIT, to screen for asymptomatic proximal DVT, conditional recommendation to do
Bilateral lower extremity compression ultrasonography
If acute isolated HIT and upper extremity central venous catheter, conditional recommendation to do… And to not do…
(Do) upper extremity ultrasonography in the limb with the catheter to screen for asymptomatic DVT
(Don’t) upper extremity ultrasonography in limbs without the catheter
How long to anticoagulate in acute isolated HIT with no DVT found?
Until platelet count recovery
If subacute HIT A, which is preferred between DOACs or warfarin
DOACs
What is Suspected vs. Acute vs. subacute HIT A vs. subacute HIT B vs. Remote
Suspected: low platelets Acute: positive immunoassay and if possible functional assay Subacute A: platelet count recovery Subacute B: functional assay recovery Remote: immunoassay recovery
If acute HIT or subacute HIT A and requiring cardiovascular surgery
Delay surgery until functional assay recovery (subacute B) or immunoassay recovery (remote HIT)
If cannot delay surgery while acute HIT or subacute HIT A
Intraoperative Bivalirudin or plasma exchange and then intraoperative heparin or intraoperative heparin with a potent antiplatelet like tirofiban
If cardiovascular surgery needed in a patient with subacute HIT B or remote HIT
Intraoperative heparin
If subacute HIT A or acute HIT and need PCI
Bivalirudin
If Bivalirudin is not available, can use Argatroban
If subacute HIT B or remote HIT and need PCI
Bivalirudin
Heparin is an acceptable alternative if no other anticoag can be used
If acute HIT on dialysis
Argatroban, Danaparoid, or Bivalirudin
In subacute HIT A, subacute HIT B, or remote HIT and on dialysis and not otherwise receiving anticoagulation
Regional Citrate
If remote HIT and require VTE tx/prophylaxis
DOAC, warfarin, fondaparinux, or Danaparoid > UFH/LMWH
How long to wear an emergency identifier post HIT
3 months
