Context Studies comparing outcomes of cardiac care in women vs men yield various
results, with some suggesting worse outcomes for women and others suggesting
Objective To determine whether extent of coronary disease, treatment strategy,
and follow-up time influence the risk of death in women vs men among patients
who have had cardiac catheterization.
Design, Setting, and Patients We studied a large inception cohort by using detailed clinical data
from a registry of 37 401 patients undergoing cardiac catheterization
in Alberta, Canada, from 1995-2000, with follow-up through December 31, 2001.
Main Outcome Measures The risk of death for women vs men was assessed for all patients combined
and then in analyses stratified by degree of coronary anatomic risk and by
treatment strategy (no revascularization, percutaneous coronary intervention
[PCI], coronary artery bypass graft [CABG] surgery). The latter analysis included
a graphic assessment of the changing relative risk over time for women vs
Results Women had higher 1-year mortality than men did (5.6% vs 4.6%; P<.001). However, stratified analyses demonstrated that
sex differences in risk occurred only early after catheterization and were
most apparent among patients undergoing revascularization. The early risk-adjusted
relative risks for women vs men were elevated at 3.49 (95% confidence interval
[CI], 1.95-6.24) for CABG surgery and 2.38 (95% CI, 1.48-3.83) for PCI on
day 1 after catheterization, with a subsequent decrease in relative risk over
time to equivalence in risk between sexes before 1 year.
Conclusions Sex-based differences in death rates after cardiac catheterization are
time- and treatment-specific. This finding may at least partially explain
the discrepancies in results from earlier studies on sex differences in outcomes
of cardiac care.