Coronary artery disease is one of the main causes of morbidity
and mortality worldwide. Throughout the last decade improvements
in the diagnosis and treatment of atherosclerosis have caused a
marked reduction in the morbidity and mortality in men, whereas the
rate of recurrent atherothrombotic events, including cardiovascular
death, in women has increased. As platelet reactivity plays a vital role
in thrombus formation and atherosclerosis, dual antiplatelet therapy
with both aspirin and clopidogrel has become the cornerstone in the
treatment of patients undergoing coronary stent implantation and
those presenting with Acute Coronary Syndrome (ACS). Previous
studies have suggested that women do not accrue equal therapeutic
benefit of antithrombotic therapy. Although multiple contributing
factors have been described, the physiological mechanism behind
this gender disparity remains unclear.
Gender differences in platelet function: Influence of gender
on platelet biology was put forward over 30 years ago [1–4]. Sites of
potential gender differences are in molecular mechanisms of platelet
adhesion/aggregation. Latest works have shown that a gender and
age difference in platelet count significantly (with higher values in
women vs. men and in younger vs. older subjects), and that platelets
in women have a higher number of surface receptors and to bind a
greater amount of fibrinogen [5,3,6,7]. paradoxically females have
higher bleeding tendency over males.
However, some are of opinion that platelet count and surface
expression of glycoprotein (GP) Ib -IX-V (responsible for initiating
adhesion through a von Will ebrand factor) and GP IIb/IIIa receptors
(responsible for initiating aggregation mainly through fibrinogen)
may not accurately reflect overall platelet reactivity .
Cardiovascular risk is still underestimated in women though they
are experiencing higher mortality and worse prognosis after acute
cardiovascular events. Cause of Acute coronary syndrome in females
is plaque erosion as compared men where majority is due to plaque
rupture which is nidus for platelet activation. Gender differences are
seen in thrombotic and hemorrhagic risk during Dual Antiplatelet
Therapy (DAPT), thus suggesting a potential variability in platelet
reactivity according to sex.
Women are generally less represented than men in cardiovascular
trials for reasons that include:
- Underestimation of cardiac risk due to atypical nature of angina,
misinterpretation of symptoms, biased referral for cardiac
testing, lower rates of appropriate diagnosis or treatment
and lesser rates of referral to coronary angiography for acute
coronary syndromes (ACS) .
- Lower prevalence of cardiovascular diseases in women below the
age of 65. On the other hand, women included in antithrombotic
drug trials are on average older and have more comorbidities and
risk factors than men, and are thus at a higher risk of adverse
outcomes, including thrombotic and bleeding events .
- Moreover, because women are more prone to bleeding
complications than men owing, to lower body weight, lower
glomerular filtration rates, and more frequent overdosing of
antithrombotic drugs, the net clinical benefit of antiplatelet
agents tends to be generally smaller in women than in age-matched
Evidence that gender differences play a role in platelet reactivity
was first reported over 30 years ago and this observation has been
confirmed in many studies.
Compare the MACCE Between the Studies: Differences in
vessel wall biology between men and women, as well as the direct
influence of sex hormones (oestrogens, progesterone or androgens)
on platelets or their indirect effect on the vasculature, might be
underlying conditions from a biological point of view.
Since platelet reactivity plays a pivotal role in thrombus formation
and atherosclerosis, dual antiplatelet therapy with both aspirin and
clopidogrel has become the mainstay in the treatment of patients
undergoing coronary stent implantation and those presenting with ACS. However, both drugs result in a wide interindividual range in
platelet inhibition and the association between high end treatment
platelet inhibition and the occurrence of adverse events is well
Therefore, the aim of the present study is to compare the
magnitude of High on-Treatment Platelet Reactivity (HRPR) between
genders in patients on dual antiplatelet therapy undergoing elective
and emergency coronary stenting and their correlation with MACCE.