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.
Veterans Affairs Medical Center, University of Iowa College of Pharmacy, Iowa City, Iowa 52246, USA. heather-bream@uiowa.edu
Heather R
HR
Bream-Rouwenhorst
Ryan A
RA
Hobbs
Phillip A
PA
Horwitz
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