The gender effect in stroke thrombolysis: of CASES, controls, and treatment-effect modification.
BACKGROUND
Large studies of patients with acute stroke not receiving thrombolytic therapy have repeatedly demonstrated poorer outcomes for women compared to men. An analysis of five pooled randomized controlled trials testing IV recombinant tissue plasminogen activator (rtPA) demonstrated that rtPA benefits women more than men; the usual gender difference, apparent among controls, was totally nullified in the rtPA group. This nullification of the usual gender effect among rtPA-treated patients has not been confirmed.


METHODS
We analyzed baseline characteristics and functional outcomes in men vs women in the Canadian Alteplase for Stroke Effectiveness Study (CASES), a multicenter study that collected outcomes data for patients treated with rtPA in Canada to assess the safety and effectiveness of alteplase for stroke in the context of routine care.


RESULTS
Among 1,110 patients, including 615 men and 505 women, a normal or near normal outcome at 90 days was found in 37.1% of men vs 36.0% of women (p = 0.71). This was essentially unchanged after adjusting for differences in baseline characteristics, including age >70, glucose, hypertension, atrial fibrillation, hypercholesterolemia, baseline National Institute of Health Stroke Severity, and baseline Alberta Stroke Program Early CT score (35.2% in men vs 38.2% in women, p = 0.332). Ninety-day mortality was similar between the sexes in both the adjusted and unadjusted analysis.


CONCLUSIONS
There was no difference in 90-day outcomes in recombinant tissue plasminogen activator (rtPA)-treated men and rtPA-treated women. This is consistent with the pooled analysis of randomized controlled trials, showing greater benefit for thrombolysis in women and nullification of the usual gender difference in outcome.
Kent
David M
DM
Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA 02111, USA. Dkent1@tuftsmedicalcenter.org
Buchan
Alastair M
AM
Hill
Michael D
MD
D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology; D002170:Canada; D016022:Case-Control Studies; D002985:Clinical Protocols; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data; D005260:Female; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D020767:Intracranial Thrombosis / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D012727:Sex Characteristics; D012737:Sex Factors; D020521:Stroke / Q000188:drug therapy* / Q000503:physiopathology; D015912:Thrombolytic Therapy / Q000706:statistics & numerical data* / Q000639:trends; D010959:Tissue Plasminogen Activator / Q000494:pharmacology; D016896:Treatment Outcome
D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator