Measurement of hemostatic indexes in conjunction with transcranial doppler sonography in patients with ventricular assist devices.
OBJECTIVE
Clinical thromboembolism (TE) remains an impediment to the chronic application of ventricular assist devices (VADs). Microembolic signals (MES) have been detected by transcranial Doppler ultrasound (TCD) in patients with VADs, although their origin and relation to TE remain undefined. We have investigated the hypothesis that hemostatic alterations are related to MES and that MES are associated with TE in a group of 27 VAD patients.


METHODS
Indexes of coagulation, fibrinolysis, and cellular activation and aggregation were measured before and during the VAD implantation period in conjunction with TCD. Groups were defined on the basis of presence of MES, degree of MES showering, and incidence of TE.


RESULTS
MES were observed in 67 (58%) of 115 of individual postoperative TCD measurements and in 21 (78%) of 27 patients. Of patients with TE, 10 (83%) of 12 had detectable MES compared with 11 (73%) of 15 patients without TE (P=0.66). MES were significantly associated with elevated thrombin generation during the implantation period, as reflected by plasma prothrombin fragment F1.2. Elevations in indexes of coagulation, platelet activation, and fibrinolysis relative to normal control subjects were found for patients with VADs with and without detected MES.


CONCLUSIONS
Although no significant relation between MES and TE in VAD patients was found, the data support the hypothesis that MES are related to increased hemostatic activity in this patient group despite aggressive anticoagulant therapy.
Wilhelm
C R
CR
Department of Surgery (Cardiothoracic) and McGowan Center for Artificial Organ Development, University of Pittsburgh, PA, USA.
Ristich
J
J
Knepper
L E
LE
Holubkov
R
R
Wisniewski
S R
SR
Kormos
R L
RL
Wagner
W R
WR
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000990:Antithrombin III / Q000032:analysis; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005342:Fibrinolysis; D005434:Flow Cytometry; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D002546:Ischemic Attack, Transient / Q000097:blood / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000032:analysis; D010447:Peptide Hydrolases / Q000032:analysis; D015539:Platelet Activation; D011516:Prothrombin / Q000032:analysis; D020521:Stroke / Q000097:blood / Q000000981:diagnostic imaging*; D013917:Thrombin / Q000378:metabolism*; D017585:Ultrasonography, Doppler, Transcranial
D010446:Peptide Fragments; C046193:antithrombin III-protease complex; C045879:prothrombin fragment 1.2; D000990:Antithrombin III; D011516:Prothrombin; D010447:Peptide Hydrolases; D013917:Thrombin