Anticoagulation Strategies in MCS: Routine, Bleeding and ... · Rimsans et al (2017) Clinical and...
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Anticoagulation Strategies in MCS: Routine, Bleeding and the Heparin Resistant Patient Mechanical Circulatory Support Symposium 2018 (Houston, TX) Charles Hoopes, MD Professor of Surgery University of Alabama (Birmingham) [email protected]
Transcript of Anticoagulation Strategies in MCS: Routine, Bleeding and ... · Rimsans et al (2017) Clinical and...
Anticoagulation Strategies in MCS: Routine, Bleeding and the Heparin Resistant Patient
Mechanical Circulatory Support Symposium 2018 (Houston, TX)
Charles Hoopes, MDProfessor of SurgeryUniversity of Alabama (Birmingham)[email protected]
Disclosure: I have no professional or financial relationship with any of the devices or technologies discussed.
“Substantial variability remains in the approach to anticoagulant and antiplatelet therapy for patients on MCS, largely because of the lack of high-quality data.”
Anticoagulation with VADs and ECMO: walking the tightrope
L Raffini (2017) Hematology
(1) device design and deployment (shear-induced platelet activation, blood path, pulsitility)
(2) anticoagulation (VKA + antiplatelet … DTI, Xa antagonists)
(3) monitoring (ACT, aPTT, PT/INR, Xa, TEG, LDH, pFHgb, microparticles)
(4) management (early ‘bridging’ and late surveillance, TTR)
Why is there a lack of consensus?
Given our general agreement on …
Defining the problem …
Understanding the mechanism …
Measuring the intervention …
Adatya and Bennett (2015)J Thorac Dis 7(12): 2129–2138
… Technique, therapy,and management
Absent or short heparin bridgeInadequate INR targetTime in Therapeutic Range (TTR)Antiplatelet therapyBiomarkers (LDH) thresholds
… a strong influence of outflow graft angle on thrombogenicity (platelet residence times and activation state characterized by shear stress accumulation) with significantly reduced thrombogenic potential for acutely-angled anastomosed outflow grafts.
Aliseda et al (2017) ASAIO 63: 14-23
“… European-Americans with a variant of CYP2C9 (CYP2C9*2) required less of the drug according to race-specific dosing models, yet African-Americans did not. While all participants, regardless of race, who carried VKORC1 required lower dose, according to race-specific dosing models, the proportional dose reduction was greater among European-Americans.”
genotype-guided dosingrace-adjusted analysisrace-specific algorithms
“… algorithms - including clinical, genetic and environmental factors - to predict a patient’s risk of hemorrhage”
The Hugh Kaul Personalized Medicine Institute at UAB
Prop of pop with poormedication compliance was 36% for anticoagulants(N=362, 10 years)
Source: US CommercialInsurance Database
Sixteen patients randomized …
Half of the dabigatran patients had a thrombotic event …
Early termination …
Comparable to RE-ALIGN results …“Pradaxa” direct thrombin inhibition
JHLT 2014 Jan;33(1):35-43
LDH > 600pfHgb > 40
… hemolysis induced pro-thrombotic state
Significant discordance betweenaPTT and anti-FXa …
prolonged aPTT with INR >1.8
Alvarez et al (2016) J Card Fail 22(7):501-11
21 cases in 15 patients
Rimsans et al (2017) Clinical and Applied Thrombosis/Hemostasis 23(5) 405-409
10 cases in 6 patients
• Bruckner et al (2009) High incidence of thromboembolic events. JHLT 28:785• Bradford et al (2015) Safety of prothrombin complex concentrate during LVAD insertion. ASAIO 61:509
Platelets are aggregated by unfractionated heparin
“… the VA ECMO weaning success rate was lower … and the in-hospital mortality higher for patients on continuous heparin infusion. We did not find any evidence … of thrombotic complications from heparin discontinuation.”
Chung et al (2017) ASAIO 63:32-36
“The apodictic adherence to anticoagulation in therapeutic dosage should be critically scrutinized in every patient.”
Artif Organs, Vol. 21, No. 9, 1997
Contact activation versustissue factor mediated coagulation
CLS = clot life spanCGT = clot growth timeCLT = clot lysis time
• standardized protocol, individual therapy
• a normocoagulable state in a prothromboticenvironment
• device specific
• CI (coagulation index) … (R, K, angle) + clot strength
• No differences in INR between TE and non-TE group
• Protocol: CI, INR, MA-AA, MA-ADP
• Fibrinogen and FVII … normal TEG R values and prolonged INR
