Thrombocytopenia in patients treated with heparin, combination antiplatelet therapy, and intra-aortic balloon pump counterpulsation.
OBJECTIVE
Determine the incidence and timing of intra-aortic balloon pump (IABP)-associated thrombocytopenia, if concomitant antiplatelet agents increase the incidence of thrombocytopenia, and the incidence of heparin-induced thrombocytopenia (HIT) in a contemporary IABP population.


BACKGROUND
Previous studies predate the current practice of treating acute coronary syndrome patients with heparin and aspirin plus thienopyridines and glycoprotein IIb/IIIa receptor antagonists such that data are unavailable to determine if their co-administration worsens IABP-associated thrombocytopenia.


METHODS
A retrospective cohort study of adult IABP patients (n = 107) from 2002 to 2006 was performed to determine the indication for and duration of counterpulsation, platelet counts during and for 7 days postcounterpulsation, medications potentially contributing to thrombocytopenia, and HIT antibody results if obtained.


RESULTS
Thrombocytopenia, defined as platelets <150,000/mL or >50% decrease from baseline, occurred in 57.9% of patients. Overall, platelets declined to 60.2 +/- 22.8% of baseline with the mean (+/- standard deviation) nadir on day 2.8 +/- 2.0. Comparing patients who received heparin, aspirin, thienopyridines, and glycoprotein IIb/IIIa antagonists (n = 44) versus heparinized patients +/- aspirin (n = 45), platelet nadirs were 62.7 +/- 20.9% versus 58.3 +/- 23.9% of baseline levels, respectively (P = 0.42). The incidence of HIT was 2.8% in the entire cohort.


CONCLUSIONS
IABP-associated thrombocytopenia occurred in 57.9% of this cohort. HIT was diagnosed in 2.8% and should be considered as a diagnosis if platelet counts do not stabilize or continue to fall after 3-4 days of counterpulsation. Increased use of antiplatelet therapy does not impact the degree of thrombocytopenia although the current practice of prompt IABP removal may offset this effect.
Bream-Rouwenhorst
Heather R
HR
Veterans Affairs Medical Center, University of Iowa College of Pharmacy, Iowa City, Iowa 52246, USA. heather-bream@uiowa.edu
Hobbs
Ryan A
RA
Horwitz
Phillip A
PA
D000925:Anticoagulants / Q000009:adverse effects; D001241:Aspirin / Q000009:adverse effects; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D007423:Intra-Aortic Balloon Pumping / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects; D010976:Platelet Count; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000209:etiology
D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011725:Pyridines; C446540:thienopyridine; D006493:Heparin; D001241:Aspirin