Evaluation of platelets in heart failure: is platelet activity related to etiology, functional class, or clinical outcomes?
OBJECTIVE
We sought to determine whether platelet activity in patients with heart failure is related to an ischemic versus nonischemic etiologic condition, clinical disease severity, or adverse clinical outcomes.


BACKGROUND
Platelet activity may affect outcome in patients with heart failure. A prospective evaluation of the relation of baseline platelet function to etiologic condition, New York Heart Association (NYHA) class, and clinical outcomes has not been previously reported.


METHODS
Ninety-six consecutive outpatients with ambulatory heart failure with an ejection fraction <0.40 and NYHA Class II to IV symptoms who presented to the Duke Heart Failure Clinic and 14 healthy control subjects formed the study groups. Baseline characteristics and blood analyzed for thromboxane (Tx) B2, 6-keto PGF(1alpha), platelet contractile force, adenosine diphosphate/collagen shear-induced closure time, whole blood aggregation and CD41, CD31, CD62p, and CD51/CD61 by flow cytometry were determined. Survival status and hospitalizations were determined in the heart failure patient cohort.


RESULTS
The median age of patients was 65 years (22% female, 64% white). An ischemic etiologic condition was present in 61% of patients. The population had mild to moderate heart failure: NYHA class I (1%), II (41%), III (46%), and IV (12.5%) and severe ventricular dysfunction (median ejection fraction = 0.20). There were 39 clinical events (7 deaths, 3 cardiac transplants, 29 other first hospitalizations) in 305 median days of observation. Platelet activity, indicated by whole blood aggregation with 5 micromol adenosine diphosphate (P =.04) and Tx B2 (P =.01), was higher in patients with heart failure. Whole blood aggregation was greater than the 90th percentile in 22% of patients with heart failure versus 7% of control subjects. Platelet function did not differ for any of the markers between the ischemic and nonischemic groups and was not affected by antecedent aspirin. There was no relation of NYHA class or the occurrence of events to platelet activity.


CONCLUSIONS
Platelet activity is heightened in 22% of outpatients with stable heart failure symptoms and is not affected by antecedent aspirin therapy. The degree of platelet activation is similar in ischemic and nonischemic patients with heart failure and is not related to clinical disease severity. Current methods to assess platelet activation do not appear to predict outcome.
Gurbel
Paul A
PA
Sinai Center for Thrombosis Research, Baltimore, Md 21215, USA. Pgurbel@Sinai-balt.com
Gattis
Wendy A
WA
Fuzaylov
Sergey F
SF
Gaulden
Laura
L
Hasselblad
Vic
V
Serebruany
Victor L
VL
O'Connor
Christopher M
CM
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage; D001241:Aspirin / Q000008:administration & dosage; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015539:Platelet Activation / Q000187:drug effects / Q000502:physiology; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology; D011446:Prospective Studies
D000925:Anticoagulants; D000244:Adenosine Diphosphate; D001241:Aspirin