Swissmedic Vigilance News

Sex differences in outcomes of intravenous thrombolysis in acute ischaemic
stroke patients with preadmission use of antiplatelets
Roberta Noseda 1 , Carlo W. Cereda 2 , Alessandro Ceschi 1
1
Clinical Pharmacology and Toxicology Department, Institute of Pharmacological Sciences of Southern Switzerland,
Ente Ospedaliero Cantonale, Lugano
2
Neurocenter of Southern Switzerland, Ospedale Regionale di Lugano, Ente Ospedaliero Cantonale, Lugano
The article presented below is an abbreviated version of the original article published by Noseda R. et al., 2023 (1).
Introduction
Intravenous thrombolysis (IVT) with recombinant tissue
plasminogen activator (rtPA) is the only approved
pharmacological reperfusion treatment for acute
ischaemic stroke (AIS) (2). Clinical outcomes of IVT
with rtPA rely strictly on patient individuality, which
encompasses biological sex, among others (3, 4).
Sex differences have been investigated in relation
to safety and functional outcomes of IVT with rtPA
in patients with AIS, but with heterogeneous and
unsettled findings (5–7).
Although the use of antiplatelets (single or dual)
before stroke onset has been associated with an increased
risk of haemorrhagic complications following
IVT (7), preadmission use of antiplatelets is not
considered a contraindication for IVT with rtPA in
eligible patients with AIS (2). Data on the association
of preadmission use of antiplatelets with safety
and functional outcomes after IVT with rtPA in patients
with AIS are also contradictory (8–11).
Platelet count and reactivity are higher in females
(12–14), therefore females with preadmission
use of antiplatelets and AIS may respond differently
from males to IVT. There is a lack of studies
specifically evaluating the interaction between patient
sex and preadmission use of antiplatelets in
relation to both safety and functional outcomes of
IVT in patients with AIS.
The aim of this cohort study was to compare safety
and functional outcomes after IVT between females
and males with regard to preadmission use
of antiplatelets in a large multicentre Swiss cohort
reflecting daily clinical practice in acute stroke care.
Methods
Consecutive patients admitted from 1 January
2014 to 31 January 31 2020 to hospitals participating
in the Swiss Stroke Registry (SSR) (15) presenting
with AIS and receiving IVT without endovascular
treatment were included. Patients who used
anticoagulants before admission and patients with
missing data on age, sex and preadmission use of
antiplatelets were excluded. The study population
was divided into two groups based on patient biological
sex and thereafter compared in terms of
preadmission use of antiplatelets.
The safety outcome was in-hospital symptomatic
intracerebral haemorrhage (sICH) occurring within
seven days of AIS onset. The functional outcome was
functional independence, defined as a modified
Rankin Scale (mRS) score of 0 to 2, at three months
after hospital discharge. The mRS is an ordinal scale
that ranges from 0 (no symptoms) to 6 (death),
which is widely used to measure functional outcomes
(16).
Multivariable logistic regression models were fitted
to assess the association between patient sex and
each outcome according to preadmission use of antiplatelets
(single vs no use or dual vs no use). With
this aim, interaction variables between patient sex
and preadmission use of antiplatelets (either single
or dual) were introduced. Regression models were
adjusted for meaningful demographic and clinical
patient variables that could potentially influence
outcome measures. These variables included age,
National Institutes of Health Stroke Scale (NIHSS)
score at admission, pre-stroke disability (defined
by mRS score), medical history of hypertension,
Swissmedic Vigilance News | Edition 31 – November 2023
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